History of technology, the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek techne, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both fine and applied. When it first appeared in English in the 17th century, it was used to mean a discussion of the applied arts only, and gradually these “arts” themselves came to be the object of the designation. By the early 20th century the term embraced a growing range of means, processes, and ideas in addition to tools and machines. By mid-century technology was defined by such phrases as “the means or activity by which man seeks to change or manipulate his environment.” Even such broad definitions have been criticized by observers who point out the increasing difficulty of distinguishing between scientific inquiry and technological activity.
A highly compressed account of the history of technology such as this one must adopt a rigorous methodological pattern if it is to do justice to the subject without grossly distorting it one way or another. The plan followed in the present article is primarily chronological, tracing the development of technology through phases that succeed each other in time. Obviously, the division between phases is to a large extent arbitrary. One factor in the weighting has been the enormous acceleration of Western technological development in recent centuries; Eastern technology is considered in this article in the main only as it relates to the development of modern technology.
Within each chronological phase a standard method has been adopted for surveying the technological experience and innovations. This begins with a brief review of the general social conditions of the period under discussion, and then goes on to consider the dominant materials and sources of power of the period, and their application to food production, manufacturing industry, building construction, transport and communications, military technology, and medical technology. In a final section the sociocultural consequences of technological change in the period are examined. This framework is modified according to the particular requirements of every period discussions of new materials, for instance, occupy a substantial place in the accounts of earlier phases when new metals were being introduced but are comparatively unimportant in descriptions of some of the later phases but the general pattern is retained throughout. One key factor that does not fit easily into this pattern is that of the development of tools. It has seemed most convenient to relate these to the study of materials, rather than to any particular application, but it has not been possible to be completely consistent in this treatment. Further discussion of specific areas of technological development is provided in a variety of other articles:
General Considerations
Essentially, techniques are methods of creating new tools and products of tools, and the capacity for constructing such artifacts is a determining characteristic of humanlike species. Other species make artifacts: bees build elaborate hives to deposit their honey, birds make nests, and beavers build dams. But these attributes are the result of patterns of instinctive behaviour and cannot be varied to suit rapidly changing circumstances. Human beings, in contrast to other species, do not possess highly developed instinctive reactions but do have the capacity to think systematically and creatively about techniques. Humans can thus innovate and consciously modify the environment in a way no other species has achieved. An ape may on occasion use a stick to beat bananas from a tree, but a person can fashion the stick into a cutting tool and remove a whole bunch of bananas. Somewhere in the transition between the two, the hominid, the first humanlike species, emerges. By virtue of humanity’s nature as a toolmaker, humans have therefore been technologists from the beginning, and the history of technology encompasses the whole evolution of humankind.
In using rational faculties to devise techniques and modify the environment, humankind has attacked problems other than those of survival and the production of wealth with which the term technology is usually associated today. The technique of language, for example, involves the manipulation of sounds and symbols in a meaningful way, and similarly the techniques of artistic and ritual creativity represent other aspects of the technological incentive. This article does not deal with these cultural and religious techniques, but it is valuable to establish their relationship at the outset because the history of technology reveals a profound interaction between the incentives and opportunities of technological innovation on the one hand and the sociocultural conditions of the human group within which they occur on the other.
Social involvement in technological advances
An awareness of this interaction is important in surveying the development of technology through successive civilizations. To simplify the relationship as much as possible, there are three points at which there must be some social involvement in technological innovation: social need, social resources, and a sympathetic social ethos. In default of any of these factors it is unlikely that a technological innovation will be widely adopted or be successful.
The sense of social need must be strongly felt, or people will not be prepared to devote resources to a technological innovation. The thing needed may be a more efficient cutting tool, a more powerful lifting device, a labour-saving machine, or a means of using new fuels or a new source of energy. Or, because military needs have always provided a stimulus to technological innovation, it may take the form of a requirement for better weapons. In modern societies, needs have been generated by advertising. Whatever the source of social need, it is essential that enough people be conscious of it to provide a market for an artifact or commodity that can meet the need.
Social resources are similarly an indispensable prerequisite to a successful innovation. Many inventions have foundered because the social resources vital for their realization the capital, materials, and skilled personnel were not available. The notebooks of Leonardo da Vinci are full of ideas for helicopters, submarines, and airplanes, but few of these reached even the model stage because resources of one sort or another were lacking. The resource of capital involves the existence of surplus productivity and an organization capable of directing the available wealth into channels in which the inventor can use it. The resource of materials involves the availability of appropriate metallurgical, ceramic, plastic, or textile substances that can perform whatever functions a new invention requires of them. The resource of skilled personnel implies the presence of technicians capable of constructing new artifacts and devising novel processes. A society, in short, has to be well primed with suitable resources in order to sustain technological innovation.
A sympathetic social ethos implies an environment receptive to new ideas, one in which the dominant social groups are prepared to consider innovation seriously. Such receptivity may be limited to specific fields of innovation for example, improvements in weapons or in navigational techniques or it may take the form of a more generalized attitude of inquiry, as was the case among the industrial middle classes in Britain during the 18th century, who were willing to cultivate new ideas and inventors, the breeders of such ideas. Whatever the psychological basis of inventive genius, there can be no doubt that the existence of socially important groups willing to encourage inventors and to use their ideas has been a crucial factor in the history of technology.
Social conditions are thus of the utmost importance in the development of new techniques, some of which will be considered below in more detail. It is worthwhile, however, to register another explanatory note. This concerns the rationality of technology. It has already been observed that technology involves the application of reason to techniques, and in the 20th century it came to be regarded as almost axiomatic that technology is a rational activity stemming from the traditions of modern science. Nevertheless, it should be observed that technology, in the sense in which the term is being used here, is much older than science, and also that techniques have tended to ossify over centuries of practice or to become diverted into such para-rational exercises as alchemy. Some techniques became so complex, often depending upon processes of chemical change that were not understood even when they were widely practiced, that technology sometimes became itself a “mystery” or cult into which an apprentice had to be initiated like a priest into holy orders, and in which it was more important to copy an ancient formula than to innovate. The modern philosophy of progress cannot be read back into the history of technology; for most of its long existence technology has been virtually stagnant, mysterious, and even irrational. It is not fanciful to see some lingering fragments of this powerful technological tradition in the modern world, and there is more than an element of irrationality in the contemporary dilemma of a highly technological society contemplating the likelihood that it will use its sophisticated techniques in order to accomplish its own destruction. It is thus necessary to beware of over facile identification of technology with the “progressive” forces in contemporary civilization.
On the other hand it is impossible to deny that there is a progressive element in technology, as it is clear from the most elementary survey that the acquisition of techniques is a cumulative matter, in which each generation inherits a stock of techniques on which it can build if it chooses and if social conditions permit. Over a long period of time the history of technology inevitably highlights the moments of innovation that show this cumulative quality as some societies advance, stage by stage, from comparatively primitive to more sophisticated techniques. But although this development has occurred and is still going on, it is not intrinsic to the nature of technology that such a process of accumulation should occur, and it has certainly not been an inevitable development. The fact that many societies have remained stagnant for long periods of time, even at quite developed stages of technological evolution, and that some have actually regressed and lost the accumulated techniques passed on to them, demonstrates the ambiguous nature of technology and the critical importance of its relationship with other social factors.
Modes of technological transmission
Another aspect of the cumulative character of technology that will require further investigation is the manner of transmission of technological innovations. This is an elusive problem, and it is necessary to accept the phenomenon of simultaneous or parallel invention in cases in which there is insufficient evidence to show the transmission of ideas in one direction or another. The mechanics of their transmission have been enormously improved in recent centuries by the printing press and other means of communication and also by the increased facility with which travelers visit the sources of innovation and carry ideas back to their own homes. Traditionally, however, the major mode of transmission has been the movement of artifacts and craftsmen. Trade in artifacts has ensured their widespread distribution and encouraged imitation. Even more important, the migration of craftsmen whether the itinerant metalworkers of early civilizations or the German rocket engineers whose expert knowledge was acquired by both the Soviet Union and the United States after World War II has promoted the spread of new technologies.
The evidence for such processes of technological transmission is a reminder that the material for the study of the history of technology comes from a variety of sources. Much of it relies, like any historical examination, on documentary matter, although this is sparse for the early civilizations because of the general lack of interest in technology on the part of scribes and chroniclers. For these societies, therefore, and for the many millennia of earlier unrecorded history in which slow but substantial technological advances were made, it is necessary to rely heavily upon archaeological evidence. Even in connection with the recent past, the historical understanding of the processes of rapid industrialization can be made deeper and more vivid by the study of “industrial archaeology.” Much valuable material of this nature has been accumulated in museums, and even more remains in the place of its use for the observation of the field worker. The historian of technology must be prepared to use all these sources, and to call upon the skills of the archaeologist, the engineer, the architect, and other specialists as appropriate.
Technology In The Ancient World
The beginnings Stone Age technology (to c. 3000 BCE)
The identification of the history of technology with the history of humanlike species does not help in fixing a precise point for its origin, because the estimates of prehistorians and anthropologists concerning the emergence of human species vary so widely. Animals occasionally use natural tools such as sticks or stones, and the creatures that became human doubtless did the same for hundreds of millennia before the first giant step of fashioning their own tools. Even then it was an interminable time before they put such toolmaking on a regular basis, and still more aeons passed as they arrived at the successive stages of standardizing their simple stone choppers and pounders and of manufacturing them that is, providing sites and assigning specialists to the work. A degree of specialization in toolmaking was achieved by the time of the Neanderthals (70,000 BCE); more-advanced tools, requiring assemblage of head and haft, were produced by Cro-Magnons (perhaps as early as 35,000 BCE); while the application of mechanical principles was achieved by pottery-making Neolithic (New Stone Age; 6000 BCE) and Metal Age peoples (about 3000 BCE).
Earliest communities
For all except approximately the past 10,000 years, humans lived almost entirely in small nomadic communities dependent for survival on their skills in gathering food, hunting and fishing, and avoiding predators. It is reasonable to suppose that most of these communities developed in tropical latitudes, especially in Africa, where climatic conditions are most favourable to a creature with such poor bodily protection as humans have. It is also reasonable to suppose that tribes moved out thence into the subtropical regions and eventually into the landmass of Eurasia, although their colonization of this region must have been severely limited by the successive periods of glaciation, which rendered large parts of it inhospitable and even uninhabitable, even though humankind has shown remarkable versatility in adapting to such unfavorable conditions.
The Neolithic Revolution
Toward the end of the last ice age, some 15,000 to 20,000 years ago, a few of the communities that were most favored by geography and climate began to make the transition from the long period of Paleolithic, or Old Stone Age, savagery to a more settled way of life depending on animal husbandry and agriculture. This period of transition, the Neolithic Period, or New Stone Age, led eventually to a marked rise in population, to a growth in the size of communities, and to the beginnings of town life. It is sometimes referred to as the Neolithic Revolution because the speed of technological innovation increased so greatly and human social and political organization underwent a corresponding increase in complexity. To understand the beginnings of technology, it is thus necessary to survey developments from the Old Stone Age through the New Stone Age down to the emergence of the first urban civilizations about 3000 BCE.
The material that gives its name and a technological unity to these periods of prehistory is stone. Though it may be assumed that primitive humans used other materials such as wood, bone, fur, leaves, and grasses before they mastered the use of stone, apart from bone antlers, presumably used as picks in flint mines and elsewhere, and other fragments of bone implements, none of these has survived. The stone tools of early humans, on the other hand, have survived in surprising abundance, and over the many millennia of prehistory important advances in technique were made in the use of stone. Stones became tools only when they were shaped deliberately for specific purposes, and, for this to be done efficiently, suitable hard and fine-grained stones had to be found and means devised for shaping them and particularly for putting a cutting edge on them. Flint became a very popular stone for this purpose, although fine sandstones and certain volcanic rocks were also widely used. There is much Paleolithic evidence of skill in flaking and polishing stones to make scraping and cutting tools. These early tools were held in the hand, but gradually ways of protecting the hand from sharp edges on the stone, at first by wrapping one end in fur or grass or setting it in a wooden handle, were devised. Much later the technique of fixing the stone head to a haft converted these hand tools into more versatile tools and weapons.
With the widening mastery of the material world in the Neolithic Period, other substances were brought into service, such as clay for pottery and brick, and increasing competence in handling textile raw materials led to the creation of the first woven fabrics to take the place of animal skins. About the same time, curiosity about the behaviour of metallic oxides in the presence of fire promoted one of the most significant technological innovations of all time and marked the succession from the Stone Age to the Metal Age.
Power
The use of fire was another basic technique mastered at some unknown time in the Old Stone Age. The discovery that fire could be tamed and controlled and the further discovery that a fire could be generated by persistent friction between two dry wooden surfaces were momentous. Fire was the most important contribution of prehistory to power technology, although little power was obtained directly from fire except as defense against wild animals. For the most part, prehistoric communities remained completely dependent upon manpower, but, in making the transition to a more settled pattern of life in the New Stone Age, they began to derive some power from animals that had been domesticated. It also seems likely that by the end of prehistoric times the sail had emerged as a means of harnessing the wind for small boats, beginning a long sequence of developments in marine transport.
Tools and weapons
The basic tools of prehistoric peoples were determined by the materials at their disposal. But once they had acquired the techniques of working stone, they were resourceful in devising tools and weapons with points and barbs. Thus, the stone-headed spear, the harpoon, and the arrow all came into widespread use. The spear was given increased impetus by the spear-thrower, a notched pole that gave a sling effect. The bow and arrow were an even more effective combination, the use of which is clearly demonstrated in the earliest “documentary” evidence in the history of technology, the cave paintings of southern France and northern Spain, which depict the bow being used in hunting. The ingenuity of these hunters is also shown in their slings, throwing-sticks (the boomerang of Australian Aboriginal people is a remarkable surviving example), blowguns, bird snares, fish and animal traps, and nets. These tools did not evolve uniformly, as each community developed only those instruments that were most suitable for its own specialized purposes, but all were in use by the end of the Stone Age. In addition, the Neolithic Revolution had contributed some important new tools that were not primarily concerned with hunting. These were the first mechanical applications of rotary action in the shape of the potter’s wheel, the bow drill, the pole lathe, and the wheel itself. It is not possible to be sure when these significant devices were invented, but their presence in the early urban civilizations suggests some continuity with the late Neolithic Period. The potter’s wheel, driven by kicks from the operator, and the wheels of early vehicles both gave continuous rotary movement in one direction. The drill and the lathe, on the other hand, were derived from the bow and had the effect of spinning the drill piece or the workpiece first in one direction and then in the other.
Developments in food production brought further refinements in tools. The processes of food production in Paleolithic times were simple, consisting of gathering, hunting, and fishing. If these methods proved inadequate to sustain a community, it moved to better hunting grounds or perished. With the onset of the Neolithic Revolution, new food-producing skills were devised to serve the needs of agriculture and animal husbandry. Digging sticks and the first crude plows, stone sickles, querns that ground grain by friction between two stones and, most complicated of all, irrigation techniques for keeping the ground watered and fertile all these became well established in the great subtropical river valleys of Egypt and Mesopotamia in the millennia before 3000 BCE.
Building techniques
Prehistoric building techniques also underwent significant developments in the Neolithic Revolution. Nothing is known of the building ability of Paleolithic peoples beyond what can be inferred from a few fragments of stone shelters, but in the New Stone Age some impressive structures were erected, primarily tombs and burial mounds and other religious edifices, but also, toward the end of the period, domestic housing in which sun-dried brick was first used. In northern Europe, where the Neolithic transformation began later than around the eastern Mediterranean and lasted longer, huge stone monuments, of which Stonehenge in England is the outstanding example, still bear eloquent testimony to the technical skill, not to mention the imagination and mathematical competence, of the later Stone Age societies.
Manufacturing
Manufacturing industry had its origin in the New Stone Age, with the application of techniques for grinding corn, baking clay, spinning and weaving textiles, and also, it seems likely, for dyeing, fermenting, and distilling. Some evidence for all these processes can be derived from archaeological findings, and some of them at least were developing into specialized crafts by the time the first urban civilizations appeared. In the same way, the early metalworkers were beginning to acquire the techniques of extracting and working the softer metals, gold, silver, copper, and tin, that were to make their successors a select class of craftsmen. All these incipient fields of specialization, moreover, implied developing trade between different communities and regions, and again the archaeological evidence of the transfer of manufactured products in the later Stone Age is impressive. Flint arrowheads of particular types, for example, can be found widely dispersed over Europe, and the implication of a common locus of manufacture for each is strong.
Such transmission suggests improving facilities for transport and communication. Paleolithic people presumably depended entirely on their own feet, and this remained the normal mode of transport throughout the Stone Age. Domestication of the ox, the donkey, and the camel undoubtedly brought some help, although difficulties in harnessing the horse long delayed its effective use. The dugout canoe and the birch-bark canoe demonstrated the potential of water transport, and, again, there is some evidence that the sail had already appeared by the end of the New Stone Age.
It is notable that the developments so far described in human prehistory took place over a long period of time, compared with the 5,000 years of recorded history, and that they took place first in very small areas of Earth’s surface and involved populations minute by modern criteria. The Neolithic Revolution occurred first in those parts of the world with an unusual combination of qualities: a warm climate, encouraging rapid crop growth, and an annual cycle of flooding that naturally regenerated the fertility of the land. On the Eurasian-African landmass such conditions occur only in Egypt, Mesopotamia, northern India, and some of the great river valleys of China. It was there, then, that men and women of the New Stone Age were stimulated to develop and apply new techniques of agriculture, animal husbandry, irrigation, and manufacture, and it was there that their enterprise was rewarded by increasing productivity, which encouraged the growth of population and triggered a succession of sociopolitical changes that converted the settled Neolithic communities into the first civilizations. Elsewhere the stimulus to technological innovation was lacking or was unrewarded, so that those areas had to await the transmission of technical expertise from the more highly favoured areas. Herein is rooted the separation of the great world civilizations, for while the Egyptian and Mesopotamian civilizations spread their influence westward through the Mediterranean and Europe, those of India and China were limited by geographical barriers to their own hinterlands, which, although vast, were largely isolated from the mainstream of Western technological progress.
The urban revolution (c. 3000–500 BCE)
The technological change so far described took place very slowly over a long period of time, in response to only the most basic social needs, the search for food and shelter, and with few social resources available for any activity other than the fulfillment of these needs. About 5,000 years ago, however, a momentous cultural transition began to take place in a few well-favoured geographical situations. It generated new needs and resources and was accompanied by a significant increase in technological innovation. It was the beginning of the invention of the city.
Craftsmen and scientists
The accumulated agricultural skill of the New Stone Age had made possible a growth in population, and the larger population in turn created a need for the products of specialized craftsmen in a wide range of commodities. These craftsmen included a number of metalworkers, first those treating metals that could be easily obtained in metallic form and particularly the soft metals, such as gold and copper, which could be fashioned by beating. Then came the discovery of the possibility of extracting certain metals from the ores in which they generally occur. Probably the first such material to be used was the carbonate of copper known as malachite, then already in use as a cosmetic and easily reduced to copper in a strong fire. It is impossible to be precise about the time and place of this discovery, but its consequences were tremendous. It led to the search for other metallic ores, to the development of metallurgy, to the encouragement of trade in order to secure specific metals, and to the further development of specialist skills. It contributed substantially to the emergence of urban societies, as it relied heavily upon trade and manufacturing industries, and thus to the rise of the first civilizations. The Stone Age gave way to the early Metal Age, and a new epoch in the story of humankind had begun.
By fairly general consent, civilization consists of a large society with a common culture, settled communities, and sophisticated institutions, all of which presuppose a mastery of elementary literacy and numeration. Mastery of the civilized arts was a minority pursuit in the early civilizations, in all probability the carefully guarded possession of a priestly caste. The very existence of these skills, however, even in the hands of a small minority of the population, is significant because they made available a facility for recording and transmitting information that greatly enlarged the scope for innovation and speculative thought.
Hitherto, technology had existed without the benefit of science, but, by the time of the first Sumerian astronomers, who plotted the motion of the heavenly bodies with remarkable accuracy and based calculations about the calendar and irrigation systems upon their observations, the possibility of a creative relationship between science and technology had appeared. The first fruits of this relationship appeared in greatly improved abilities to measure land, weigh, and keep time, all practical techniques, essential to any complex society, and inconceivable without literacy and the beginnings of scientific observation. With the emergence of these skills in the 3rd millennium BCE, the first civilizations arose in the valleys of the Nile and of the Tigris-Euphrates.
Copper and bronze
The fact that the era of the early civilizations coincides with the technological classification of the Copper Age and Bronze Age is a clue to the technological basis of these societies. The softness of copper, gold, and silver made it inevitable that they should be the first to be worked, but archaeologists now seem to agree that there was no true “Copper Age” except perhaps for a short period at the beginning of Egyptian civilization, because the very softness of that metal limited its utility for everything except decoration or coinage. Attention was thus given early to means of hardening copper to make satisfactory tools and weapons. The reduction of mixed metallic ores probably led to the discovery of alloying, whereby copper was fused with other metals to make bronze. Several bronzes were made, including some containing lead, antimony, and arsenic, but by far the most popular and widespread was that of copper and tin in proportions of about 10 to one. This was a hard yellowish metal that could be melted and cast into the shape required. The bronze smiths took over from the coppersmiths and goldsmiths the technique of heating the metal in a crucible over a strong fire and casting it into simple clay or stone molds to make ax-heads or spearheads or other solid shapes. For the crafting of hollow vessels or sculpture, they devised the so-called cire perdue technique, in which the shape to be molded is formed in wax and set in clay, the wax then being melted and drained out to leave a cavity into which the molten metal is poured.
Bronze became the most important material of the early civilizations, and elaborate arrangements were made to ensure a continuous supply of it. Metals were scarce in the alluvial river valleys where civilization developed and therefore had to be imported. This need led to complicated trading relationships and mining operations at great distances from the homeland. Tin presented a particularly severe problem, as it was in short supply throughout the Middle East. The Bronze Age civilizations were compelled to search far beyond their own frontiers for sources of the metal, and in the process knowledge of the civilized arts was gradually transmitted westward along the developing Mediterranean trade routes.
In most aspects other than the use of metals, the transition from the technology of the New Stone Age to that of early civilizations was fairly gradual, although there was a general increase in competence as specialized skills became more clearly defined, and in techniques of building there were enormous increases in the scale of enterprises. There were no great innovations in power technology, but important improvements were made in the construction of furnaces and kilns in response to the requirements of the metalworkers and potters and of new artisans such as glassworkers. Also, the sailing ship assumed a definitive shape, progressing from a vessel with a small sail rigged in its bows and suitable only for sailing before the prevailing wind up the Nile River, into the substantial oceangoing ship of the later Egyptian dynasties, with a large rectangular sail rigged amidships. Egyptian and Phoenician ships of this type could sail before the wind and across the wind, but for making headway into the wind they had to resort to manpower. Nevertheless, they accomplished remarkable feats of navigation, sailing the length of the Mediterranean and even passing through the Pillars of Hercules into the Atlantic.
Irrigation
Techniques of food production also showed many improvements over Neolithic methods, including one outstanding innovation in the shape of systematic irrigation. The civilizations of Egypt and Mesopotamia depended heavily upon the two great river systems, the Nile and the Tigris-Euphrates, which both watered the ground with their annual floods and rejuvenated it with the rich alluvium they deposited. The Nile flooded with regularity each summer, and the civilizations building in its valley early learned the technique of basin irrigation, ponding back the floodwater for as long as possible after the river had receded, so that enriched soil could bring forth a harvest before the floods of the following season. In the Tigris-Euphrates valley the irrigation problem was more complex, because the floods were less predictable, more fierce, and came earlier than those of the northward-flowing Nile. They also carried more alluvium, which tended to choke irrigation channels. The task of the Sumerian irrigation engineers was that of channeling water from the rivers during the summer months, impounding it, and distributing it to the fields in small installments. The Sumerian system eventually broke down because it led to an accumulation of salt in the soil, with a consequent loss of fertility. Both systems, however, depended on a high degree of social control, requiring skill in measuring and marking out the land and an intricate legal code to ensure justice in the distribution of precious water. Both systems, moreover, depended on intricate engineering in building dikes and embankments, canals and aqueducts (with lengthy stretches underground to prevent loss by evaporation), and the use of water-raising devices such as the shadoof, a balanced beam with a counterweight on one end and a bucket to lift the water on the other.
Urban manufacturing
Manufacturing industry in the early civilizations concentrated on such products as pottery, wines, oils, and cosmetics, which had begun to circulate along the incipient trade routes before the introduction of metals; these became the commodities traded for the metals. In pottery, the potter’s wheel became widely used for spinning the clay into the desired shape, but the older technique of building pots by hand from rolls of clay remained in use for some purposes. In the production of wines and oils various forms of press were developed, while the development of cooking, brewing, and preservatives justified the assertion that the science of chemistry began in the kitchen. Cosmetics too were an offshoot of culinary art.
Pack animals were still the primary means of land transport, the wheeled vehicle developing slowly to meet the divergent needs of agriculture, trade, and war. In the latter category, the chariot appeared as a weapon, even though its use was limited by the continuing difficulty of harnessing a horse. Military technology brought the development of metal plates for armour.
Building
In building technology the major developments concerned the scale of operations rather than any particular innovation. The late Stone Age communities of Mesopotamia had already built extensively in sun-dried brick. Their successors continued the technique but extended its scale to construct the massive square temples called ziggurats. These had a core and facing of bricks, the facing walls sloping slightly inward and broken by regular pilasters built into the brickwork, the whole structure ascending in two or three stages to a temple on the summit. Sumerians were also the first to build columns with brick made from local clay, which also provided the writing material for the scribes.
In Egypt, clay was scarce but good building stone was plentiful, and builders used it in constructing the pyramids and temples that remain today as outstanding monuments of Egyptian civilization. Stones were pulled on rollers and raised up the successive stages of the structure by ramps and by balanced levers adapted from the water-raising shadoof. The stones were shaped by skilled masons, and they were placed in position under the careful supervision of priest-architects who were clearly competent mathematicians and astronomers, as is evident from the precise astronomical alignments. It seems certain that the heavy labour of construction fell upon armies of slaves, which helps to explain both the achievements and limitations of early civilizations. Slaves were usually one of the fruits of military conquest, which presupposes a period of successful territorial expansion, although their status as a subject race could be perpetuated indefinitely. Slave populations provided a competent and cheap labour force for the major constructional works that have been described. On the other hand, the availability of slave labour discouraged technological innovation, a social fact that goes far toward explaining the comparative stagnation of mechanical invention in the ancient world.
Transmitting knowledge
In the ancient world, technological knowledge was transmitted by traders, who went out in search of tin and other commodities, and by craftsmen in metal, stone, leather, and the other mediums, who passed their skills to others by direct instruction or by providing models that challenged other craftsmen to copy them. This transmission through intermediary contact was occurring between the ancient civilizations and their neighbours to the north and west during the 2nd millennium BCE. The pace quickened in the subsequent millennium, distinct new civilizations arising in Crete and Mycenae, in Troy and Carthage. Finally, the introduction of the technique of working iron profoundly changed the capabilities and resources of human societies and ushered in the Classical civilizations of Greece and Rome.
Technological achievements of Greece and Rome (500 BCE–500 CE)
The contributions of Greece and Rome in philosophy and religion, political and legal institutions, poetry and drama, and in the realm of scientific speculation stand in spectacular contrast with their relatively limited contributions in technology. Their mechanical innovation was not distinguished, and, even in the realms of military and construction engineering, in which they showed great ingenuity and aesthetic sensibility, their work represented more a consummation of earlier lines of development than a dramatic innovation. This apparent paradox of the Classical period of the ancient world requires explanation, and the history of technology can provide some clues to the solution of the problem.
The mastery of iron
The outstanding technological factor of the Greco-Roman world was the smelting of iron, a technique derived from unknown metallurgists, probably in Asia Minor, about 1000 BCE that spread far beyond the provincial frontiers of the Roman Empire. The use of the metal had become general in Greece and the Aegean Islands by the dawn of the Classical period about 500 BCE, and it appears to have spread quickly westward thereafter. Iron ore, long a familiar material, had defied reduction into metallic form because of the great heat required in the furnace to perform the chemical transformation (about 1,535 °C [2,795 °F] compared with the 1,083 °C [1,981 °F] necessary for the reduction of copper ores). To reach this temperature, furnace construction had to be improved and ways devised to maintain the heat for several hours. Throughout the Classical period these conditions were achieved only on a small scale, in furnaces burning charcoal and using foot bellows to intensify the heat, and even in these furnaces the heat was not sufficient to reduce the ore completely to molten metal. Instead, a small spongy ball of iron called a bloom was produced in the bottom of the furnace. This was extracted by breaking open the furnace, and then it was hammered into bars of wrought iron, which could be shaped as required by further heating and hammering. Apart from its greater abundance, iron for most purposes provided a harder and stronger material than the earlier metals, although the impossibility of casting it into molds like bronze was an inconvenience. At an early date some smiths devised the cementation process for reheating bars of iron between layers of charcoal to carburize the surface of the iron and thus to produce a coat of steel. Such case-hardened iron could be further heated, hammered, and tempered to make knife and sword blades of high quality. The very best steel in Roman times was Seric steel, brought into the Western world from India, where it was produced in blocks a few inches in diameter by a crucible process, melting the ingredients in an enclosed vessel to achieve purity and consistency in the chemical combination.
Mechanical contrivances
Though slight, the mechanical achievements of the Greco-Roman centuries were not without significance. The world had one of its great mechanical geniuses in Archimedes, who devised remarkable weapons to protect his native Syracuse from Roman invasion and applied his powerful mind to such basic mechanical contrivances as the screw, the pulley, and the lever. Alexandrian engineers, such as Ctesibius and Hero, invented a wealth of ingenious mechanical contrivances including pumps, wind and hydraulic organs, compressed-air engines, and screw-cutting machines. They also devised toys and automata such as the aeolipile, which may be regarded as the first successful steam turbine. Little practical use was found for these inventions, but the Alexandrian school marks an important transition from very simple mechanisms to the more complex devices that properly deserve to be considered “machines.” In a sense it provided a starting point for modern mechanical practice.
The Romans were responsible, through the application and development of available machines, for an important technological transformation: the widespread introduction of rotary motion. This was exemplified in the use of the treadmill for powering cranes and other heavy lifting operations, the introduction of rotary water-raising devices for irrigation works (a scoop wheel powered by a treadmill), and the development of the waterwheel as a prime mover. The 1st-century-BCE Roman engineer Vitruvius gave an account of watermills, and by the end of the Roman era many were in operation.
Agriculture
Iron Age technology was applied to agriculture in the form of the iron (or iron-tipped) plowshare, which opened up the possibility of deeper plowing and of cultivating heavier soils than those normally worked in the Greco-Roman period. The construction of plows improved slowly during these centuries, but the moldboard for turning over the earth did not appear until the 11th century CE, so that the capacity of turning the sod depended more on the wrists of the plowman than on the strength of his draft team; this discouraged tackling heavy ground. The potentialities of the heavy plow were thus not fully exploited in the temperate areas of Europe until after the Roman period. Elsewhere, in the drier climates of North Africa and Spain, the Romans were responsible for extensive irrigation systems, using the Archimedean screw and the noria (an animal- or water-powered scoop wheel) to raise water.
Building
Though many buildings of the Greeks survive as splendid monuments to the civilized communities that built them, as technological monuments they are of little significance. The Greeks adopted a form of column and lintel construction that had been used in Egypt for centuries and was derived from experience of timber construction. In no major sense did Greek building constitute a technological innovation. The Romans copied the Greek style for most ceremonial purposes, but in other respects they were important innovators in building technology. They made extensive use of fired brick and tile as well as stone; they developed a strong cement that would set under water; and they explored the architectural possibilities of the arch, the vault, and the dome. They then applied these techniques in amphitheaters, aqueducts, tunnels, bridges, walls, lighthouses, and roads. Taken together, these constructional works may fairly be regarded as the primary technological achievement of the Romans.
Other fields of technology
In manufacturing, transport, and military technology, the achievements of the Greco-Roman period are not remarkable. The major manufacturing crafts the making of pottery and glass, weaving, leatherworking, fine-metalworking, and so on followed the lines of previous societies, albeit with important developments in style. Superbly decorated Athenian pottery, for example, was widely dispersed along the trade routes of the Mediterranean, and the Romans made good quality pottery available throughout their empire through the manufacture and trade of the standardized red ware called terra sigillata, which was produced in large quantities at several sites in Italy and Gaul.
Transport
Transport, again, followed earlier precedents, the sailing ship emerging as a seagoing vessel with a carvel-built hull (that is, with planks meeting edge-to-edge rather than overlapping as in clinker-built designs), and a fully developed keel with stempost and sternpost. The Greek sailing ship was equipped with a square or rectangular sail to receive a following wind and one or more banks of oarsmen to propel the ship when the wind was contrary. The Greeks began to develop a specialized fighting ship, provided with a ram in the prow, and the cargo ship, dispensing with oarsmen and relying entirely upon the wind, was also well established by the early years of Classical Greece. The Romans took over both forms, but without significant innovation. They gave much more attention to inland transport than to the sea, and they constructed a remarkable network of carefully aligned and well-laid roads, often paved over long stretches, throughout the provinces of the empire. Along these strategic highways the legions marched rapidly to the site of any crisis at which their presence was required. The roads also served for the development of trade, but their primary function was always military, as a vital means of keeping a vast empire in subjection.
Military technology
Roman military technology was inventive on occasion, as in the great siege catapults, depending on both torsion and tension power. But the standard equipment of the legionnaire was simple and conservative, consisting of an iron helmet and breastplate, with a short sword and an iron-tipped spear. As most of their opponents were also equipped with iron weapons and sometimes with superior devices, such as the Celtic chariots, the Roman military achievements depended more on organization and discipline than on technological superiority.
The Greco-Roman era was distinguished for the scientific activity of some of its greatest philosophers. In keeping with Greek speculative thought, however, this tended to be strongly conceptual so that it was in mathematics and other abstract studies that the main scientific achievements are to be found. Some of these had some practical significance, as in the study of perspective effects in building construction. Aristotle in many ways expressed the inquiring empiricism that has caused scientists to seek an explanation for their physical environment. In at least one field, that of medicine and its related subjects, Greek inquiry assumed a highly practical form, Hippocrates and Galen laying the foundations of modern medical science. But this was exceptional, and the normal Hellenic attitude was to pursue scientific enquiry in the realm of ideas without much thought of the possible technological consequences.
From The Middle Ages To 1750
Medieval advance (500–1500 CE)
The millennium between the collapse of the Western Roman Empire in the 5th century CE and the beginning of the colonial expansion of western Europe in the late 15th century has been known traditionally as the Middle Ages, and the first half of this period consists of the five centuries of the Dark Ages. We now know that the period was not as socially stagnant as this title suggests. In the first place, many of the institutions of the later empire survived the collapse and profoundly influenced the formation of the new civilization that developed in western Europe. The Christian church was the outstanding institution of this type, but Roman conceptions of law and administration also continued to exert an influence long after the departure of the legions from the western provinces. Second, and more important, the Teutonic tribes who moved into a large part of western Europe did not come empty-handed, and in some respects their technology was superior to that of the Romans. It has already been observed that they were people of the Iron Age, and although much about the origins of the heavy plow remains obscure these tribes appear to have been the first people with sufficiently strong iron plowshares to undertake the systematic settlement of the forested lowlands of northern and western Europe, the heavy soils of which had frustrated the agricultural techniques of their predecessors.
The invaders came thus as colonizers. They may have been regarded as “barbarians” by the Romanized inhabitants of western Europe who naturally resented their intrusion, and the effect of their invasion was certainly to disrupt trade, industry, and town life. But the newcomers also provided an element of innovation and vitality. About 1000 CE the conditions of comparative political stability necessary for the reestablishment of a vigorous commercial and urban life had been secured by the success of the kingdoms of the region in either absorbing or keeping out the last of the invaders from the East, and thereafter for 500 years the new civilization grew in strength and began to experiment in all aspects of human endeavour. Much of this process involved recovering the knowledge and achievements of the ancient world. The history of medieval technology is thus largely the story of the preservation, recovery, and modification of earlier achievements. But by the end of the period Western civilization had begun to produce some remarkable technological innovations that were to be of the utmost significance.
Innovation
The word innovation raises a problem of great importance in the history of technology. Strictly, an innovation is something entirely new, but there is no such thing as an unprecedented technological innovation because it is impossible for an inventor to work in a vacuum and, however ingenious his invention, it must arise out of his own previous experience. The task of distinguishing an element of novelty in an invention remains a problem of patent law down to the present day, but the problem is made relatively easy by the possession of full documentary records covering previous inventions in many countries. For the millennium of the Middle Ages, however, few such records exist, and it is frequently difficult to explain how particular innovations were introduced to western Europe. The problem is especially perplexing because it is known that many inventions of the period had been developed independently and previously in other civilizations, and it is sometimes difficult if not impossible to know whether something is spontaneous innovation or an invention that had been transmitted by some as yet undiscovered route from those who had originated it in other societies.
The problem is important because it generates a conflict of interpretations about the transmission of technology. On the one hand there is the theory of the diffusionists, according to which all innovation has moved westward from the long-established civilizations of the ancient world, with Egypt and Mesopotamia as the two favourite candidates for the ultimate source of the process. On the other hand is the theory of spontaneous innovation, according to which the primary determinant of technological innovation is social need. Scholarship is as yet unable to solve the problem so far as technological advances of the Middle Ages are concerned because much information is missing. But it does seem likely that at least some of the key inventions of the period the windmill and gunpowder are good examples were developed spontaneously. It is quite certain, however, that others, such as silk working, were transmitted to the West, and, however original the contribution of Western civilization to technological innovation, there can be no doubt at all that in its early centuries at least it looked to the East for ideas and inspiration.
Byzantium
The immediate eastern neighbour of the new civilization of medieval Europe was Byzantium, the surviving bastion of the Roman Empire based in Constantinople (Istanbul), which endured for 1,000 years after the collapse of the western half of the empire. There the literature and traditions of Hellenic civilization were perpetuated, becoming increasingly available to the curiosity and greed of the West through the traders who arrived from Venice and elsewhere. Apart from the influence on Western architectural style of such Byzantine masterpieces as the great domed structure of the Hagia Sophia, the technological contribution of Byzantium itself was probably slight, but it served to mediate between the West and other civilizations one or more stages removed, such as the Islamic world, India, and China.
Islam
The Islamic world had become a civilization of colossal expansive energy in the 7th century and had imposed a unity of religion and culture on much of southwest Asia and North Africa. From the point of view of technological dissemination, the importance of Islam lay in the Arab assimilation of the scientific and technological achievements of Hellenic civilization, to which it made significant additions, and the whole became available to the West through the Moors in Spain, the Arabs in Sicily and the Holy Land, and through commercial contacts with the Levant and North Africa.
India
Islam also provided a transmission belt for some of the technology of East and South Asia, especially that of India and China. The ancient Hindu and Buddhist cultures of the Indian subcontinent had long-established trading connections with the Arab world to the west and came under strong Muslim influence themselves after the Mughal conquest in the 16th century. Indian artisans early acquired an expertise in ironworking and enjoyed a wide reputation for their metal artifacts and textile techniques, but there is little evidence that technical innovation figured prominently in Indian history before the foundation of European trading stations in the 16th century.
China
Civilization flourished continuously in China from about 2000 BCE, when the first of the historical dynasties emerged. From the beginning it was a civilization that valued technological skill in the form of hydraulic engineering, for its survival depended on controlling the enriching but destructive floods of the Huang He (Yellow River). Other technologies appeared at a remarkably early date, including the casting of iron, the production of porcelain, and the manufacture of brass and paper. As one dynasty followed another, Chinese civilization came under the domination of a bureaucratic elite, the mandarins, who gave continuity and stability to Chinese life but who also became a conservative influence on innovation, resisting the introduction of new techniques unless they provided a clear benefit to the bureaucracy. Such an innovation was the development of the water-powered mechanical clock, which achieved an ingenious and elaborate form in the machine built under the supervision of Su Song in 1088. This was driven by a waterwheel that moved regularly, making one part-revolution as each bucket on its rim was filled in turn.
The links between China and the West remained tenuous until modern times, but the occasional encounter such as that resulting from the journey of Marco Polo in 1271–95 alerted the West to the superiority of Chinese technology and stimulated a vigorous westward transfer of techniques. Western knowledge of silk working, the magnetic compass, papermaking, and porcelain were all derived from China. In the latter case, Europeans admired the fine porcelain imported from China for several centuries before they were able to produce anything of a similar quality. Having achieved a condition of comparative social stability, however, the Chinese mandarinate did little to encourage innovation or trading contacts with the outside world. Under their influence, no social group emerged in China equivalent to the mercantile class that flourished in the West and did much to promote trade and industry. The result was that China dropped behind the West in technological skills until the political revolutions and social upheavals of the 20th century awakened the Chinese to the importance of these skills to economic prosperity and inspired a determination to acquire them.
Despite the acquisition of many techniques from the East, the Western world of 500–1500 was forced to solve most of its problems on its own initiative. In doing so it transformed an agrarian society based upon a subsistence economy into a dynamic society with increased productivity sustaining trade, industry, and town life on a steadily growing scale. This was primarily a technological achievement, and one of considerable magnitude.
Power sources
The outstanding feature of this achievement was a revolution in the sources of power. With no large slave labour force to draw on, Europe experienced a labour shortage that stimulated a search for alternative sources of power and the introduction of laboursaving machinery. The first instrument of this power revolution was the horse. By the invention of the horseshoe, the padded, rigid horse collar, and the stirrup, all of which first appeared in the West in the centuries of the Dark Ages, the horse was transformed from an ancillary beast of burden useful only for light duties into a highly versatile source of energy in peace and war. Once the horse could be harnessed to the heavy plow by means of the horse collar, it became a more efficient draft animal than the ox, and the introduction of the stirrup made the mounted warrior supreme in medieval warfare and initiated complex social changes to sustain the great expense of the knight, his armour, and his steed, in a society close to the subsistence line.
Even more significant was the success of medieval technology in harnessing water and wind power. The Romans had pioneered the use of waterpower in the later empire, and some of their techniques probably survived. The type of water mill that flourished first in northern Europe, however, appears to have been the Norse mill, using a horizontally mounted waterwheel driving a pair of grindstones directly, without the intervention of gearing. Examples of this simple type of mill survive in Scandinavia and in the Shetlands; it also occurred in southern Europe, where it was known as the Greek mill. It is possible that a proportion of the 5,624 mills recorded in the Domesday Book of England in 1086 were of this type, although it is probable that by that date the vertically mounted undershot wheel had established itself as more appropriate to the gentle landscape of England; the Norse mill requires a good head of water to turn the wheel at an adequate grinding speed without gearing for the upper millstone (the practice of rotating the upper stone above a stationary bed stone became universal at an early date). Most of the Domesday water mills were used for grinding grain, but in the following centuries other important uses were devised in fulling cloth (shrinking and felting woolen fabrics), sawing wood, and crushing vegetable seeds for oil. Overshot wheels also were introduced where there was sufficient head of water, and the competence of the medieval millwrights in building mills and earthworks and in constructing increasingly elaborate trains of gearing grew correspondingly.
The sail had been used to harness wind power from the dawn of civilization, but the windmill was unknown in the West until the end of the 12th century. Present evidence suggests that the windmill developed spontaneously in the West; though there are precedents in Persia and China, the question remains open. What is certain is that the windmill became widely used in Europe in the Middle Ages. Wind power is generally less reliable than waterpower, but where the latter is deficient wind power is an attractive substitute. Such conditions are found in areas that suffer from drought or from a shortage of surface water and also in low-lying areas where rivers offer little energy. Windmills have thus flourished in places such as Spain or the downlands of England on the one hand, and in the fenlands and polders of the Netherlands on the other hand. The first type of windmill to be widely adopted was the post-mill, in which the whole body of the mill pivots on a post and can be turned to face the sails into the wind. By the 15th century, however, many were adopting the tower-mill type of construction, in which the body of the mill remains stationary with only the cap moving to turn the sails into the wind. As with the water mill, the development of the windmill brought not only greater mechanical power but also greater knowledge of mechanical contrivances, which was applied in making clocks and other devices.
Agriculture and crafts
With new sources of power at its disposal, medieval Europe was able greatly to increase productivity. This is abundantly apparent in agriculture, where the replacement of the ox by the faster gaited horse and the introduction of new crops brought about a distinct improvement in the quantity and variety of food, with a consequent improvement in the diet and energy of the population. It was also apparent in the developing industries of the period, especially the woolen cloth industry in which the spinning wheel was introduced, partially mechanizing this important process, and the practice of using waterpower to drive fulling stocks (wooden hammers raised by cams on a driving shaft) had a profound effect on the location of the industry in England in the later centuries of the Middle Ages. The same principle was adapted to the paper industry late in the Middle Ages, the rags from which paper was derived being pulverized by hammers similar to fulling stocks.
Meanwhile, the traditional crafts flourished within the expanding towns, where there was a growing market for the products of the rope makers, barrel makers (coopers), leatherworkers (curriers), and metalworkers (goldsmiths and silversmiths), to mention only a few of the more important crafts. New crafts such as that of the soapmakers developed in the towns. The technique of making soap appears to have been a Teutonic innovation of the Dark Ages, being unknown in the ancient civilizations. The process consists of decomposing animal or vegetable fats by boiling them with a strong alkali. Long before it became popular for personal cleansing, soap was a valuable industrial commodity for scouring textile fabrics. Its manufacture was one of the first industrial processes to make extensive use of coal as a fuel, and the development of the coal industry in northern Europe constitutes another important medieval innovation, no previous civilization having made any systematic attempt to exploit coal. The mining techniques remained unsophisticated as long as coal was obtainable near the surface, but as the search for the mineral led to greater and greater depths the industry copied methods that had already evolved in the metal-mining industries of north and central Europe. The extent of this evolution was brilliantly summarized by Georgius Agricola in his De re metallica, published in 1556. This large, abundantly illustrated book shows techniques of shafting, pumping (by treadmill, animal power, and waterpower), and of conveying the ore won from the mines in trucks, which anticipated the development of the railways. It is impossible to date precisely the emergence of these important techniques, but the fact that they were well established when Agricola observed them suggests that they had a long ancestry.
Architecture
Relatively few structures survive from the Dark Ages, but the later centuries of the medieval period were a great age of building. The Romanesque and Gothic architecture that produced the outstanding aesthetic contribution of the Middle Ages embodied significant technological innovations. The architect-engineers, who had clearly studied Classical building techniques, showed a readiness to depart from their models and thus to devise a style that was distinctively their own. Their solutions to the problems of constructing very tall masonry buildings while preserving as much natural light as possible were the cross-rib vault, the flying buttress, and the great window panels providing scope for the new craft of the glazier using coloured glass with startling effect.
Military technology
The same period saw the evolution of the fortified stronghold from the Anglo-Saxon motte-and-bailey, a timber tower encircled by a timber and earth wall, to the formidable, fully developed masonry castle that had become an anachronism by the end of the Middle Ages because of the development of artillery. Intrinsic to this innovation were the invention of gunpowder and the development of techniques for casting metals, especially iron. Gunpowder appeared in western Europe in the mid-13th century, although its formula had been known in East Asia long before that date. It consists of a mixture of carbon, sulfur, and saltpetre, of which the first two were available from charcoal and deposits of volcanic sulfur in Europe, whereas saltpetre had to be crystallized by a noxious process of boiling stable sweepings and other decaying refuse. The consolidation of these ingredients into an explosive powder had become an established yet hazardous industry by the close of the Middle Ages.
The first effective cannon appear to have been made of wrought-iron bars strapped together, but although barrels continued to be made in this way for some purposes, the practice of casting cannon in bronze became widespread. The technique of casting in bronze had been known for several millennia, but the casting of cannon presented problems of size and reliability. It is likely that the bronzesmiths were able to draw on the experience of techniques devised by the bell founders as an important adjunct to medieval church building, as the casting of a large bell posed similar problems of heating a substantial amount of metal and of pouring it into a suitable mold. Bronze, however, was an expensive metal to manufacture in bulk, so that the widespread use of cannon in war had to depend upon improvements in iron-casting techniques.
The manufacture of cast iron is the great metallurgical innovation of the Middle Ages. It must be remembered that from the beginning of the Iron Age until late in the Middle Ages the iron ore smelted in the available furnaces had not been completely converted to its liquid form. In the 15th century, however, the development of the blast furnace made possible this fusion, with the result that the molten metal could be poured directly into molds ready to receive it. The emergence of the blast furnace was the result of attempts to increase the size of the traditional blooms. Greater size made necessary the provision of a continuous blast of air, usually from bellows driven by a waterwheel, and the combination increased the internal temperature of the furnace so that the iron became molten. At first, the disk of solid iron left in the bottom of the furnace was regarded as undesirable waste by the iron manufacturer; it possessed properties completely unlike those of the more familiar wrought iron, being crystalline and brittle and thus of no use in the traditional iron forge. But it was soon discovered that the new iron could be cast and turned to profit, particularly in the manufacture of cannon.
Transport
Medieval technology made few contributions to inland transport, though there was some experimentation in bridge building and in the construction of canals; lock gates were developed as early as 1180, when they were employed on the canal between Brugge (now in Belgium) and the sea. Roads remained indifferent where they existed at all, and vehicles were clumsy throughout the period. Wayfarers like Chaucer’s pilgrims traveled on horseback, and this was to remain the best mode of inland transport for centuries to come.
Sea transport was a different story. Here the Middle Ages produced a decisive technological achievement: the creation of a reliable oceangoing ship depending entirely on wind power instead of a combination of wind and muscle. The vital steps in this evolution were, first, the combination of the traditional square sail, used with little modification from Egyptian times through the Roman Empire to the Viking long boats, with the triangular lateen sail developed in the Arab dhow and adopted in the Mediterranean, which gave it the “lateen” (Latin) association attributed to it by the northern seafarers. This combination allowed ships so equipped to sail close to the wind. Second, the adoption of the sternpost rudder gave greatly increased maneuverability, allowing ships to take full advantage of their improved sail power in tacking into a contrary wind. Third, the introduction of the magnetic compass provided a means of checking navigation on the open seas in any weather. The convergence of these improvements in the ships of the later Middle Ages, together with other improvements in construction and equipment such as better barrels for carrying water, more reliable ropes, sails, and anchors, the availability of navigational charts (first recorded in use on board ship in 1270), and the astrolabe (for measuring the angle of the Sun or a star above the horizon) lent confidence to adventurous mariners and thus led directly to the voyages of discovery that marked the end of the Middle Ages and the beginning of the expansion of Europe that has characterized modern times.
Communications
While transport technology was evolving toward these revolutionary developments, techniques of recording and communication were making no less momentous advances. The medieval interest in mechanical contrivances is well illustrated by the development of the mechanical clock, the oldest of which, driven by weights and controlled by a verge, an oscillating arm engaging with a gear wheel, and dated 1386, survives in Salisbury Cathedral, England. Clocks driven by springs had appeared by the mid-15th century, making it possible to construct more compact mechanisms and preparing the way for the portable clock. The problem of overcoming the diminishing power of the spring as it unwound was solved by the simple compensating mechanism of the fusee a conical drum on the shaft that permitted the spring to exert an increasing moment, or tendency to increase motion, as its power declined. It has been argued that the medieval fascination with clocks reflects an increased sense of the importance of timekeeping in business and elsewhere, but it can be seen with equal justice as representing a new sense of inquiry into the possibilities and practical uses of mechanical devices.
Even more significant than the invention of the mechanical clock was the 15th-century invention of printing with movable metal type. The details of this epochal invention are disappointingly obscure, but there is general agreement that the first large-scale printing workshop was that established at Mainz by Johannes Gutenberg, which was producing a sufficient quantity of accurate type to print a Vulgate Bible about 1455. It is clear, however, that this invention drew heavily upon long previous experience with block printing using a single block to print a design or picture and on developments in typecasting and ink making. It also made heavy demands on the paper industry, which had been established in Europe since the 12th century but had developed slowly until the invention of printing and the subsequent vogue for the printed word. The printing press itself, vital for securing a firm and even print over the whole page, was an adaptation of the screw press already familiar in the winepress and other applications. The printers found an enormous demand for their product, so that the technique spread rapidly and the printed word became an essential medium of political, social, religious, and scientific communication as well as a convenient means for the dissemination of news and information. By 1500 almost 40,000 recorded editions of books had been printed in 14 European countries, with Germany and Italy accounting for two-thirds. Few single inventions have had such far-reaching consequences.
For all its isolation and intellectual deprivation, the new civilization that took shape in western Europe in the millennium 500 to 1500 achieved some astonishing feats of technological innovation. The intellectual curiosity that led to the foundation of the first universities in the 12th century and applied itself to the recovery of the ancient learning from whatever source it could be obtained was the mainspring also of the technological resourcefulness that encouraged the introduction of the windmill, the improvement and wider application of waterpower, the development of new industrial techniques, the invention of the mechanical clock and gunpowder, the evolution of the sailing ship, and the invention of large-scale printing. Such achievements could not have taken place within a static society. Technological innovation was both the cause and the effect of dynamic development. It is no coincidence that these achievements occurred within the context of a European society that was increasing in population and productivity, stimulating industrial and commercial activity, and expressing itself in the life of new towns and striking cultural activity. Medieval technology mirrored the aspiration of a new and dynamic civilization.
The emergence of Western technology (1500–1750)
The technological history of the Middle Ages was one of slow but substantial development. In the succeeding period the tempo of change increased markedly and was associated with profound social, political, religious, and intellectual upheavals in western Europe.
The emergence of the nation-state, the cleavage of the Christian church by the Protestant Reformation, the Renaissance and its accompanying scientific revolution, and the overseas expansion of European states all had interactions with developing technology. This expansion became possible after the advance in naval technology opened up the ocean routes to Western navigators. The conversion of voyages of discovery into imperialism and colonization was made possible by the new firepower. The combination of light, maneuverable ships with the firepower of iron cannon gave European adventurers a decisive advantage, enhanced by other technological assets.
The Reformation, not itself a factor of major significance to the history of technology, nevertheless had interactions with it; the capacity of the new printing presses to disseminate all points of view contributed to the religious upheavals, while the intellectual ferment provoked by the Reformation resulted in a rigorous assertion of the vocational character of work and thus stimulated industrial and commercial activity and technological innovation. It is an indication of the nature of this encouragement that so many of the inventors and scientists of the period were Calvinists, Puritans, and, in England, Dissenters.
The Renaissance
The Renaissance had more obviously technological content than the Reformation. The concept of “renaissance” is elusive. Since the scholars of the Middle Ages had already achieved a very full recovery of the literary legacy of the ancient world, as a “rebirth” of knowledge the Renaissance marked rather a point of transition after which the posture of deference to the ancients began to be replaced by a consciously dynamic, progressive attitude. Even while they looked back to Classical models, Renaissance men looked for ways of improving upon them. This attitude is outstandingly represented in the genius of Leonardo da Vinci. As an artist of original perception he was recognized by his contemporaries, but some of his most novel work is recorded in his notebooks and was virtually unknown in his own time. This included ingenious designs for submarines, airplanes, and helicopters and drawings of elaborate trains of gears and of the patterns of flow in liquids. The early 16th century was not yet ready for these novelties: they met no specific social need, and the resources necessary for their development were not available.
An often overlooked aspect of the Renaissance is the scientific revolution that accompanied it. As with the term Renaissance itself, the concept is complex, having to do with intellectual liberation from the ancient world. For centuries the authority of Aristotle in dynamics, of Ptolemy in astronomy, and of Galen in medicine had been taken for granted. Beginning in the 16th century their authority was challenged and overthrown, and scientists set out by observation and experiment to establish new explanatory models of the natural world. One distinctive characteristic of these models was that they were tentative, never receiving the authoritarian prestige long accorded to the ancient masters. Since this fundamental shift of emphasis, science has been committed to a progressive, forward-looking attitude and has come increasingly to seek practical applications for scientific research.
Technology performed a service for science in this revolution by providing it with instruments that greatly enhanced its powers. The use of the telescope by Galileo to observe the moons of Jupiter was a dramatic example of this service, but the telescope was only one of many tools and instruments that proved valuable in navigation, mapmaking, and laboratory experiments. More significant were the services of the new sciences to technology, and the most important of these was the theoretical preparation for the invention of the steam engine.
The steam engine
The researches of a number of scientists, especially those of Robert Boyle of England with atmospheric pressure, of Otto von Guericke of Germany with a vacuum, and of the French Huguenot Denis Papin with pressure vessels, helped to equip practical technologists with the theoretical basis of steam power. Distressingly little is known about the manner in which this knowledge was assimilated by pioneers such as Thomas Savery and Thomas Newcomen, but it is inconceivable that they could have been ignorant of it. Savery took out a patent for a “new Invention for Raiseing of Water and occasioning Motion to all Sorts of Mill Work by the Impellent Force of Fire” in 1698 (No. 356). His apparatus depended on the condensation of steam in a vessel, creating a partial vacuum into which water was forced by atmospheric pressure.
Credit for the first commercially successful steam engine, however, must go to Newcomen, who erected his first machine near Dudley Castle in Staffordshire in 1712. It operated by atmospheric pressure on the top face of a piston in a cylinder, in the lower part of which steam was condensed to create a partial vacuum. The piston was connected to one end of a rocking beam, the other end of which carried the pumping rod in the mine shaft. Newcomen was a tradesman in Dartmouth, Devon, and his engines were robust but unsophisticated. Their heavy fuel consumption made them uneconomical when used where coal was expensive, but in the British coalfields they performed an essential service by keeping deep mines clear of water and were extensively adopted for this purpose. In this way the early steam engines fulfilled one of the most pressing needs of British industry in the 18th century. Although waterpower and wind power remained the basic sources of power for industry, a new prime mover had thus appeared in the shape of the steam engine, with tremendous potential for further development as and when new applications could be found for it.
Metallurgy and mining
One cause of the rising demand for coal in Britain was the depletion of the woodland and supplies of charcoal, making manufacturers anxious to find a new source of fuel. Of particular importance were experiments of the iron industry in using coal instead of charcoal to smelt iron ore and to process cast iron into wrought iron and steel. The first success in these attempts came in 1709, when Abraham Darby, a Quaker ironfounder in Shropshire, used coke to reduce iron ore in his enlarged and improved blast furnace. Other processes, such as glassmaking, brickmaking, and the manufacture of pottery, had already adopted coal as their staple fuel. Great technical improvements had taken place in all these processes. In ceramics, for instance, the long efforts of European manufacturers to imitate the hard, translucent quality of Chinese porcelain culminated in Meissen at the beginning of the 18th century; the process was subsequently discovered independently in Britain in the middle of the century. Stoneware, requiring a lower firing temperature than porcelain, had achieved great decorative distinction in the 17th century as a result of the Dutch success with opaque white tin glazes at their Delft potteries, and the process had been widely imitated.
The period from 1500 to 1750 witnessed a steady expansion in mining for minerals other than coal and iron. The gold and silver mines of Saxony and Bohemia provided the inspiration for the treatise by Agricola, De re metallica, mentioned above, which distilled the cumulative experience of several centuries in mining and metalworking and became, with the help of some brilliant woodcuts and the printing press, a worldwide manual on mining practice. Queen Elizabeth I introduced German miners to England in order to develop the mineral resources of the country, and one result of this was the establishment of brass manufacture. This metal, an alloy of copper and zinc, had been known in the ancient world and in Eastern civilizations but was not developed commercially in western Europe until the 17th century. Metallic zinc had still not been isolated, but brass was made by heating copper with charcoal and calamine, an oxide of zinc mined in England in the Mendip Hills and elsewhere, and was worked up by hammering, annealing (a heating process to soften the material), and wiredrawing into a wide range of household and industrial commodities. Other nonferrous metals such as tin and lead were sought out and exploited with increasing enterprise in this period, but as their ores commonly occurred at some distance from sources of coal, as in the case of the Cornish tin mines, the employment of Newcomen engines to assist in drainage was rarely economical, and this circumstance restricted the extent of the mining operations.
Technology performed a service for science in this revolution by providing it with instruments that greatly enhanced its powers. The use of the telescope by Galileo to observe the moons of Jupiter was a dramatic example of this service, but the telescope was only one of many tools and instruments that proved valuable in navigation, mapmaking, and laboratory experiments. More significant were the services of the new sciences to technology, and the most important of these was the theoretical preparation for the invention of the steam engine.
The steam engine
The researches of a number of scientists, especially those of Robert Boyle of England with atmospheric pressure, of Otto von Guericke of Germany with a vacuum, and of the French Huguenot Denis Papin with pressure vessels, helped to equip practical technologists with the theoretical basis of steam power. Distressingly little is known about the manner in which this knowledge was assimilated by pioneers such as Thomas Savery and Thomas Newcomen, but it is inconceivable that they could have been ignorant of it. Savery took out a patent for a “new Invention for Raiseing of Water and occasioning Motion to all Sorts of Mill Work by the Impellent Force of Fire” in 1698 (No. 356). His apparatus depended on the condensation of steam in a vessel, creating a partial vacuum into which water was forced by atmospheric pressure.
Credit for the first commercially successful steam engine, however, must go to Newcomen, who erected his first machine near Dudley Castle in Staffordshire in 1712. It operated by atmospheric pressure on the top face of a piston in a cylinder, in the lower part of which steam was condensed to create a partial vacuum. The piston was connected to one end of a rocking beam, the other end of which carried the pumping rod in the mine shaft. Newcomen was a tradesman in Dartmouth, Devon, and his engines were robust but unsophisticated. Their heavy fuel consumption made them uneconomical when used where coal was expensive, but in the British coalfields they performed an essential service by keeping deep mines clear of water and were extensively adopted for this purpose. In this way the early steam engines fulfilled one of the most pressing needs of British industry in the 18th century. Although waterpower and wind power remained the basic sources of power for industry, a new prime mover had thus appeared in the shape of the steam engine, with tremendous potential for further development as and when new applications could be found for it.
Metallurgy and mining
One cause of the rising demand for coal in Britain was the depletion of the woodland and supplies of charcoal, making manufacturers anxious to find a new source of fuel. Of particular importance were experiments of the iron industry in using coal instead of charcoal to smelt iron ore and to process cast iron into wrought iron and steel. The first success in these attempts came in 1709, when Abraham Darby, a Quaker ironfounder in Shropshire, used coke to reduce iron ore in his enlarged and improved blast furnace. Other processes, such as glassmaking, brickmaking, and the manufacture of pottery, had already adopted coal as their staple fuel. Great technical improvements had taken place in all these processes. In ceramics, for instance, the long efforts of European manufacturers to imitate the hard, translucent quality of Chinese porcelain culminated in Meissen at the beginning of the 18th century; the process was subsequently discovered independently in Britain in the middle of the century. Stoneware, requiring a lower firing temperature than porcelain, had achieved great decorative distinction in the 17th century as a result of the Dutch success with opaque white tin glazes at their Delft potteries, and the process had been widely imitated.
The period from 1500 to 1750 witnessed a steady expansion in mining for minerals other than coal and iron. The gold and silver mines of Saxony and Bohemia provided the inspiration for the treatise by Agricola, De re metallica, mentioned above, which distilled the cumulative experience of several centuries in mining and metalworking and became, with the help of some brilliant woodcuts and the printing press, a worldwide manual on mining practice. Queen Elizabeth I introduced German miners to England in order to develop the mineral resources of the country, and one result of this was the establishment of brass manufacture. This metal, an alloy of copper and zinc, had been known in the ancient world and in Eastern civilizations but was not developed commercially in western Europe until the 17th century. Metallic zinc had still not been isolated, but brass was made by heating copper with charcoal and calamine, an oxide of zinc mined in England in the Mendip Hills and elsewhere, and was worked up by hammering, annealing (a heating process to soften the material), and wiredrawing into a wide range of household and industrial commodities. Other nonferrous metals such as tin and lead were sought out and exploited with increasing enterprise in this period, but as their ores commonly occurred at some distance from sources of coal, as in the case of the Cornish tin mines, the employment of Newcomen engines to assist in drainage was rarely economical, and this circumstance restricted the extent of the mining operations.
Construction
Construction techniques did not undergo any great change in the period 1500–1750. The practice of building in stone and brick became general, although timber remained an important building material for roofs and floors, and, in areas in which stone was in short supply, the half-timber type of construction retained its popularity into the 17th century. Thereafter, however, the spread of brick and tile manufacturing provided a cheap and readily available substitute, although it suffered an eclipse on aesthetic grounds in the 18th century, when Classical styles enjoyed a vogue and brick came to be regarded as inappropriate for facing such buildings. Brickmaking, however, had become an important industry for ordinary domestic building by then and, indeed, entered into the export trade as Dutch and Swedish ships regularly carried brick as ballast to the New World, providing a valuable building material for the early American settlements. Cast iron was coming into use in buildings, but only for decorative purposes. Glass was also beginning to become an important feature of buildings of all sorts, encouraging the development of an industry that still relied largely on ancient skills of fusing sand to make glass and blowing, molding, and cutting it into the shapes required.
Land reclamation
More substantial constructional techniques were required in land drainage and military fortification, although again their importance is shown rather in their scale and complexity than in any novel features. The Dutch, wrestling with the sea for centuries, had devised extensive dikes; their techniques were borrowed by English landowners in the 17th century in an attempt to reclaim tracts of fenlands.
Military fortifications
In military fortification, the French strongholds designed by Sébastien de Vauban in the late 17th century demonstrated how warfare had adapted to the new weapons and, in particular, to heavy artillery. With earthen embankments to protect their salients, these star-shaped fortresses were virtually impregnable to the assault weapons of the day. Firearms remained cumbersome, with awkward firing devices and slow reloading. The quality of weapons improved somewhat as gunsmiths became more skillful.
Transport and communications
Like constructional techniques, transport and communications made substantial progress without any great technical innovations. Road building was greatly improved in France, and, with the completion of the Canal du Midi between the Mediterranean and the Bay of Biscay in 1692, large-scale civil engineering achieved an outstanding success. The canal is 150 miles (241 km) long, with a hundred locks, a tunnel, three major aqueducts, many culverts, and a large summit reservoir.
The sea remained the greatest highway of commerce, stimulating innovation in the sailing ship. The Elizabethan galleon with its great maneuverability and firepower, the Dutch herring busses and fluitschips with their commodious hulls and shallow draft, the versatile East Indiamen of both the Dutch and the British East India companies, and the mighty ships of the line produced for the French and British navies in the 18th century indicate some of the main directions of evolution.
The needs of reliable navigation created a demand for better instruments. The quadrant was improved by conversion to the octant, using mirrors to align the image of a star with the horizon and to measure its angle more accurately: with further refinements the modern sextant evolved. Even more significant was the ingenuity shown by scientists and instrument makers in the construction of a clock that would keep accurate time at sea: such a clock, by showing the time in Greenwich when it was noon aboard ship would show how far east or west of Greenwich the ship lay (longitude). A prize of £20,000 was offered by the British Board of Longitude for this purpose in 1714, but it was not awarded until 1763 when John Harrison’s so-called No. 4 chronometer fulfilled all the requirements.
Chemistry
Robert Boyle’s contribution to the theory of steam power has been mentioned, but Boyle is more commonly recognized as the “father of chemistry,” in which field he was responsible for the recognition of an element as a material that cannot be resolved into other substances. It was not until the end of the 18th and the beginning of the 19th century, however, that the work of Antoine Lavoisier and John Dalton put modern chemical science on a firm theoretical basis. Chemistry was still struggling to free itself from the traditions of alchemy. Even alchemy was not without practical applications, for it promoted experiments with materials and led to the development of specialized laboratory equipment that was used in the manufacture of dyes, cosmetics, and certain pharmaceutical products. For the most part, pharmacy still relied upon recipes based on herbs and other natural products, but the systematic preparation of these eventually led to the discovery of useful new drugs.
The period from 1500 to 1750 witnessed the emergence of Western technology in the sense that the superior techniques of Western civilization enabled the nations that composed it to expand their influence over the whole known world. Yet, with the exception of the steam engine, this period was not marked by outstanding technological innovation. What was, perhaps, more important than any particular innovation was the evolution, however faltering and partial and limited to Britain in the first place, of a technique of innovation, or what has been called “the invention of invention.” The creation of a political and social environment conducive to invention, the building up of vast commercial resources to support inventions likely to produce profitable results, the exploitation of mineral, agricultural, and other raw material resources for industrial purposes, and, above all, the recognition of specific needs for invention and an unwillingness to be defeated by difficulties, together produced a society ripe for an industrial revolution based on technological innovation. The technological achievements of the period 1500–1750, therefore, must be judged in part by their substantial contribution to the spectacular innovations of the following period.
The Industrial Revolution (1750–1900)
The term Industrial Revolution, like similar historical concepts, is more convenient than precise. It is convenient because history requires division into periods for purposes of understanding and instruction and because there were sufficient innovations at the turn of the 18th and 19th centuries to justify the choice of this as one of the periods. The term is imprecise, however, because the Industrial Revolution has no clearly defined beginning or end. Moreover, it is misleading if it carries the implication of a once-for-all change from a “preindustrial” to a “postindustrial” society, because, as has been seen, the events of the traditional Industrial Revolution had been well prepared in a mounting tempo of industrial, commercial, and technological activity from about 1000 CE and led into a continuing acceleration of the processes of industrialization that is still proceeding in our own time. The term Industrial Revolution must thus be employed with some care. It is used below to describe an extraordinary quickening in the rate of growth and change and, more particularly, to describe the first 150 years of this period of time, as it will be convenient to pursue the developments of the 20th century separately.
The Industrial Revolution, in this sense, has been a worldwide phenomenon, at least in so far as it has occurred in all those parts of the world, of which there are very few exceptions, where the influence of Western civilization has been felt. Beyond any doubt it occurred first in Britain, and its effects spread only gradually to continental Europe and North America. Equally clearly, the Industrial Revolution that eventually transformed these parts of the Western world surpassed in magnitude the achievements of Britain, and the process was carried further to change radically the socioeconomic life of Asia, Africa, Latin America, and Australasia. The reasons for this succession of events are complex, but they were implicit in the earlier account of the buildup toward rapid industrialization. Partly through good fortune and partly through conscious effort, Britain by the early 18th century came to possess the combination of social needs and social resources that provided the necessary preconditions of commercially successful innovation and a social system capable of sustaining and institutionalizing the processes of rapid technological change once they had started. This section will therefore be concerned, in the first place, with events in Britain, although in discussing later phases of the period it will be necessary to trace the way in which British technical achievements were diffused and superseded in other parts of the Western world.
Power technology
An outstanding feature of the Industrial Revolution has been the advance in power technology. At the beginning of this period, the major sources of power available to industry and any other potential consumer were animate energy and the power of wind and water, the only exception of any significance being the atmospheric steam engines that had been installed for pumping purposes, mainly in coal mines. It is to be emphasized that this use of steam power was exceptional and remained so for most industrial purposes until well into the 19th century. Steam did not simply replace other sources of power: it transformed them. The same sort of scientific inquiry that led to the development of the steam engine was also applied to the traditional sources of inanimate energy, with the result that both waterwheels and windmills were improved in design and efficiency. Numerous engineers contributed to the refinement of waterwheel construction, and by the middle of the 19th century new designs made possible increases in the speed of revolution of the waterwheel and thus prepared the way for the emergence of the water turbine, which is still an extremely efficient device for converting energy.
Windmills
Meanwhile, British windmill construction was improved considerably by the refinements of sails and by the self-correcting device of the fantail, which kept the sails pointed into the wind. Spring sails replaced the traditional canvas rig of the windmill with the equivalent of a modern venetian blind, the shutters of which could be opened or closed, to let the wind pass through or to provide a surface upon which its pressure could be exerted. Sail design was further improved with the “patent” sail in 1807. In mills equipped with these sails, the shutters were controlled on all the sails simultaneously by a lever inside the mill connected by rod linkages through the windshaft with the bar operating the movement of the shutters on each sweep. The control could be made more fully automatic by hanging weights on the lever in the mill to determine the maximum wind pressure beyond which the shutters would open and spill the wind. Conversely, counterweights could be attached to keep the shutters in the open position. With these and other modifications, British windmills adapted to the increasing demands on power technology. But the use of wind power declined sharply in the 19th century with the spread of steam and the increasing scale of power utilization. Windmills that had satisfactorily provided power for small-scale industrial processes were unable to compete with the production of large-scale steam-powered mills.
Steam engines
Although the qualification regarding older sources of power is important, steam became the characteristic and ubiquitous power source of the British Industrial Revolution. Little development took place in the Newcomen atmospheric engine until James Watt patented a separate condenser in 1769, but from that point onward the steam engine underwent almost continuous improvements for more than a century. Watt’s separate condenser was the outcome of his work on a model of a Newcomen engine that was being used in a University of Glasgow laboratory. Watt’s inspiration was to separate the two actions of heating the cylinder with hot steam and cooling it to condense the steam for every stroke of the engine. By keeping the cylinder permanently hot and the condenser permanently cold, a great economy on energy used could be effected. This brilliantly simple idea could not be immediately incorporated in a full-scale engine because the engineering of such machines had hitherto been crude and defective. The backing of a Birmingham industrialist, Matthew Boulton, with his resources of capital and technical competence, was needed to convert the idea into a commercial success. Between 1775 and 1800, the period over which Watt’s patents were extended, the Boulton and Watt partnership produced some 500 engines, which despite their high cost in relation to a Newcomen engine were eagerly acquired by the tin-mining industrialists of Cornwall and other power users who badly needed a more economic and reliable source of energy.
During the quarter of a century in which Boulton and Watt exercised their virtual monopoly over the manufacture of improved steam engines, they introduced many important refinements. Basically they converted the engine from a single-acting (i.e., applying power only on the downward stroke of the piston) atmospheric pumping machine into a versatile prime mover that was double-acting and could be applied to rotary motion, thus driving the wheels of industry. The rotary action engine was quickly adopted by British textile manufacturer Sir Richard Arkwright for use in a cotton mill, and although the ill-fated Albion Mill, at the southern end of Blackfriars Bridge in London, was burned down in 1791, when it had been in use for only five years and was still incomplete, it demonstrated the feasibility of applying steam power to large-scale grain milling. Many other industries followed in exploring the possibilities of steam power, and it soon became widely used.
Watt’s patents had the temporary effect of restricting the development of high-pressure steam, necessary in such major power applications as the locomotive. This development came quickly once these patents lapsed in 1800. The Cornish engineer Richard Trevithick introduced higher steam pressures, achieving an unprecedented pressure of 145 pounds per square inch (10 kilograms per square centimetre) in 1802 with an experimental engine at Coalbrookdale, which worked safely and efficiently. Almost simultaneously, the versatile American engineer Oliver Evans built the first high-pressure steam engine in the United States, using, like Trevithick, a cylindrical boiler with an internal fire plate and flue. High-pressure steam engines rapidly became popular in America, partly as a result of Evans’ initiative and partly because very few Watt-type low-pressure engines crossed the Atlantic. Trevithick quickly applied his engine to a vehicle, making the first successful steam locomotive for the Penydarren tramroad in South Wales in 1804. The success, however, was technological rather than commercial because the locomotive fractured the cast iron track of the tramway: the age of the railroad had to await further development both of the permanent way and of the locomotive.
Meanwhile, the stationary steam engine advanced steadily to meet an ever-widening market of industrial requirements. High-pressure steam led to the development of the large beam pumping engines with a complex sequence of valve actions, which became universally known as Cornish engines; their distinctive characteristic was the cutoff of steam injection before the stroke was complete in order to allow the steam to do work by expanding. These engines were used all over the world for heavy pumping duties, often being shipped out and installed by Cornish engineers. Trevithick himself spent many years improving pumping engines in Latin America. Cornish engines, however, were probably most common in Cornwall itself, where they were used in large numbers in the tin and copper mining industries.
Another consequence of high-pressure steam was the practice of compounding, of using the steam twice or more at descending pressures before it was finally condensed or exhausted. The technique was first applied by Arthur Woolf, a Cornish mining engineer, who by 1811 had produced a very satisfactory and efficient compound beam engine with a high-pressure cylinder placed alongside the low-pressure cylinder, with both piston rods attached to the same pin of the parallel motion, which was a parallelogram of rods connecting the piston to the beam, patented by Watt in 1784. In 1845 John McNaught introduced an alternative form of compound beam engine, with the high-pressure cylinder on the opposite end of the beam from the low-pressure cylinder, and working with a shorter stroke. This became a very popular design. Various other methods of compounding steam engines were adopted, and the practice became increasingly widespread; in the second half of the 19th century triple- or quadruple-expansion engines were being used in industry and marine propulsion. By this time also the conventional beam-type vertical engine adopted by Newcomen and retained by Watt began to be replaced by horizontal-cylinder designs. Beam engines remained in use for some purposes until the eclipse of the reciprocating steam engine in the 20th century, and other types of vertical engine remained popular, but for both large and small duties the engine designs with horizontal cylinders became by far the most common.
A demand for power to generate electricity stimulated new thinking about the steam engine in the 1880s. The problem was that of achieving a sufficiently high rotational speed to make the dynamos function efficiently. Such speeds were beyond the range of the normal reciprocating engine (i.e., with a piston moving backward and forward in a cylinder). Designers began to investigate the possibilities of radical modifications to the reciprocating engine to achieve the speeds desired, or of devising a steam engine working on a completely different principle. In the first category, one solution was to enclose the working parts of the engine and force a lubricant around them under pressure. The Willans engine design, for instance, was of this type and was widely adopted in early British power stations. Another important modification in the reciprocating design was the uniflow engine, which increased efficiency by exhausting steam from ports in the centre of the cylinder instead of requiring it to change its direction of flow in the cylinder with every movement of the piston. Full success in achieving a high-speed steam engine, however, depended on the steam turbine, a design of such novelty that it constituted a major technological innovation. This was invented by Sir Charles Parsons in 1884. By passing steam through the blades of a series of rotors of gradually increasing size (to allow for the expansion of the steam) the energy of the steam was converted to very rapid circular motion, which was ideal for generating electricity. Many refinements have since been made in turbine construction and the size of turbines has been vastly increased, but the basic principles remain the same, and this method still provides the main source of electric power except in those areas in which the mountainous terrain permits the economic generation of hydroelectric power by water turbines. Even the most modern nuclear power plants use steam turbines because technology has not yet solved the problem of transforming nuclear energy directly into electricity. In marine propulsion, too, the steam turbine remains an important source of power despite competition from the internal-combustion engine.
Electricity
The development of electricity as a source of power preceded this conjunction with steam power late in the 19th century. The pioneering work had been done by an international collection of scientists including Benjamin Franklin of Pennsylvania, Alessandro Volta of the University of Pavia, Italy, and Michael Faraday of Britain. It was the latter who had demonstrated the nature of the elusive relationship between electricity and magnetism in 1831, and his experiments provided the point of departure for both the mechanical generation of electric current, previously available only from chemical reactions within voltaic piles or batteries, and the utilization of such current in electric motors. Both the mechanical generator and the motor depend on the rotation of a continuous coil of conducting wire between the poles of a strong magnet: turning the coil produces a current in it, while passing a current through the coil causes it to turn. Both generators and motors underwent substantial development in the middle decades of the 19th century. In particular, French, German, Belgian, and Swiss engineers evolved the most satisfactory forms of armature (the coil of wire) and produced the dynamo, which made the large-scale generation of electricity commercially feasible.
The next problem was that of finding a market. In Britain, with its now well-established tradition of steam power, coal, and coal gas, such a market was not immediately obvious. But in continental Europe and North America there was more scope for experiment. In the United States Thomas Edison applied his inventive genius to finding fresh uses for electricity, and his development of the carbon-filament lamp showed how this form of energy could rival gas as a domestic illuminant. The problem had been that electricity had been used successfully for large installations such as lighthouses in which arc lamps had been powered by generators on the premises, but no way of subdividing the electric light into many small units had been devised. The principle of the filament lamp was that a thin conductor could be made incandescent by an electric current provided that it was sealed in a vacuum to keep it from burning out. Edison and the English chemist Sir Joseph Swan experimented with various materials for the filament and both chose carbon. The result was a highly successful small lamp, which could be varied in size for any sort of requirement. It is relevant that the success of the carbon-filament lamp did not immediately mean the supersession of gas lighting. Coal gas had first been used for lighting by William Murdock at his home in Redroot, Cornwall, where he was the agent for the Boulton and Watt company, in 1792. When he moved to the headquarters of the firm at Soho in Birmingham in 1798, Matthew Boulton authorized him to experiment in lighting the buildings there by gas, and gas lighting was subsequently adopted by firms and towns all over Britain in the first half of the 19th century. Lighting was normally provided by a fishtail jet of burning gas, but under the stimulus of competition from electric lighting the quality of gas lighting was greatly enhanced by the invention of the gas mantle. Thus improved, gas lighting remained popular for some forms of street lighting until the middle of the 20th century.
Lighting alone could not provide an economical market for electricity because its use was confined to the hours of darkness. Successful commercial generation depended upon the development of other uses for electricity, and particularly on electric traction. The popularity of urban electric tramways and the adoption of electric traction on subway systems such as the London Underground thus coincided with the widespread construction of generating equipment in the late 1880s and 1890s. The subsequent spread of this form of energy is one of the most remarkable technological success stories of the 20th century, but most of the basic techniques of generation, distribution, and utilization had been mastered by the end of the 19th century.
Internal-combustion engine
Electricity does not constitute a prime mover, for however important it may be as a form of energy it has to be derived from a mechanical generator powered by water, steam, or internal combustion. The internal-combustion engine is a prime mover, and it emerged in the 19th century as a result both of greater scientific understanding of the principles of thermodynamics and of a search by engineers for a substitute for steam power in certain circumstances. In an internal-combustion engine the fuel is burned in the engine: the cannon provided an early model of a single-stroke engine; and several persons had experimented with gunpowder as a means of driving a piston in a cylinder. The major problem was that of finding a suitable fuel, and the secondary problem was that of igniting the fuel in an enclosed space to produce an action that could be easily and quickly repeated. The first problem was solved in the mid-19th century by the introduction of town gas supplies, but the second problem proved more intractable as it was difficult to maintain ignition evenly. The first successful gas engine was made by Étienne Lenoir in Paris in 1859. It was modeled closely on a horizontal steam engine, with an explosive mixture of gas and air ignited by an electric spark on alternate sides of the piston when it was in midstroke position. Although technically satisfactory, the engine was expensive to operate, and it was not until the refinement introduced by the German inventor Nikolaus Otto in 1878 that the gas engine became a commercial success. Otto adopted the four-stroke cycle of induction-compression-firing-exhaust that has been known by his name ever since. Gas engines became extensively used for small industrial establishments, which could thus dispense with the upkeep of a boiler necessary in any steam plant, however small.
Petroleum
The economic potential for the internal-combustion engine lay in the need for a light locomotive engine. This could not be provided by the gas engine, depending on a piped supply of town gas, any more than by the steam engine, with its need for a cumbersome boiler; but, by using alternative fuels derived from oil, the internal-combustion engine took to wheels, with momentous consequences. Bituminous deposits had been known in Southwest Asia from antiquity and had been worked for building material, illuminants, and medicinal products. The westward expansion of settlement in America, with many homesteads beyond the range of city gas supplies, promoted the exploitation of the easily available sources of crude oil for the manufacture of kerosene (paraffin). In 1859 the oil industry took on new significance when Edwin L. Drake bored successfully through 69 feet (21 metres) of rock to strike oil in Pennsylvania, thus inaugurating the search for and exploitation of the deep oil resources of the world. While world supplies of oil expanded dramatically, the main demand was at first for the kerosene, the middle fraction distilled from the raw material, which was used as the fuel in oil lamps. The most volatile fraction of the oil, gasoline, remained an embarrassing waste product until it was discovered that this could be burned in a light internal-combustion engine; the result was an ideal prime mover for vehicles. The way was prepared for this development by the success of oil engines burning cruder fractions of oil. Kerosene-burning oil engines, modeled closely on existing gas engines, had emerged in the 1870s, and by the late 1880s engines using the vapour of heavy oil in a jet of compressed air and working on the Otto cycle had become an attractive proposition for light duties in places too isolated to use town gas.
The greatest refinements in the heavy-oil engine are associated with the work of Rudolf Diesel of Germany, who took out his first patents in 1892. Working from thermodynamic principles of minimizing heat losses, Diesel devised an engine in which the very high compression of the air in the cylinder secured the spontaneous ignition of the oil when it was injected in a carefully determined quantity. This ensured high thermal efficiency, but it also made necessary a heavy structure because of the high compression maintained, and also a rather rough performance at low speeds compared with other oil engines. It was therefore not immediately suitable for locomotive purposes, but Diesel went on improving his engine and in the 20th century it became an important form of vehicular propulsion.
Meantime the light high-speed gasoline (petrol) engine predominated. The first applications of the new engine to locomotion were made in Germany, where Gottlieb Daimler and Carl Benz equipped the first motorcycle and the first motorcar respectively with engines of their own design in 1885. Benz’s “horseless carriage” became the prototype of the modern automobile, the development and consequences of which can be more conveniently considered in relation to the revolution in transport.
By the end of the 19th century, the internal-combustion engine was challenging the steam engine in many industrial and transport applications. It is notable that, whereas the pioneers of the steam engine had been almost all Britons, most of the innovators in internal combustion were continental Europeans and Americans. The transition, indeed, reflects the general change in international leadership in the Industrial Revolution, with Britain being gradually displaced from its position of unchallenged superiority in industrialization and technological innovation. A similar transition occurred in the theoretical understanding of heat engines: it was the work of the Frenchman Sadi Carnot and other scientific investigators that led to the new science of thermodynamics, rather than that of the British engineers who had most practical experience of the engines on which the science was based.
It should not be concluded, however, that British innovation in prime movers was confined to the steam engine, or even that steam and internal combustion represent the only significant developments in this field during the Industrial Revolution. Rather, the success of these machines stimulated speculation about alternative sources of power, and in at least one case achieved a success the full consequences of which were not completely developed. This was the hot-air engine, for which a Scotsman, Robert Stirling, took out a patent in 1816. The hot-air engine depends for its power on the expansion and displacement of air inside a cylinder, heated by the external and continuous combustion of the fuel. Even before the exposition of the laws of thermodynamics, Stirling had devised a cycle of heat transfer that was ingenious and economical. Various constructional problems limited the size of hot-air engines to very small units, so that although they were widely used for driving fans and similar light duties before the availability of the electric motor, they did not assume great technological significance. But the economy and comparative cleanness of the hot-air engine were making it once more the subject of intensive research in the early 1970s.
The transformation of power technology in the Industrial Revolution had repercussions throughout industry and society. In the first place, the demand for fuel stimulated the coal industry, which had already grown rapidly by the beginning of the 18th century, into continuing expansion and innovation. The steam engine, which enormously increased the need for coal, contributed significantly toward obtaining it by providing more efficient mine pumps and, eventually, improved ventilating equipment. Other inventions such as that of the miners’ safety lamp helped to improve working conditions, although the immediate consequence of its introduction in 1816 was to persuade mineowners to work dangerous seams, which had thitherto been regarded as inaccessible. The principle of the lamp was that the flame from the wick of an oil lamp was enclosed within a cylinder of wire gauze, through which insufficient heat passed to ignite the explosive gas (firedamp) outside. It was subsequently improved, but remained a vital source of light in coal mines until the advent of electric battery lamps. With these improvements, together with the simultaneous revolution in the transport system, British coal production increased steadily throughout the 19th century. The other important fuel for the new prime movers was petroleum, and the rapid expansion of its production has already been mentioned. In the hands of John D. Rockefeller and his Standard Oil organization it grew into a vast undertaking in the United States after the end of the Civil War, but the oil-extraction industry was not so well organized elsewhere until the 20th century.
Development of industries
Metallurgy
Another industry that interacted closely with the power revolution was that concerned with metallurgy and the metal trades. The development of techniques for working with iron and steel was one of the outstanding British achievements of the Industrial Revolution. The essential characteristic of this achievement was that changing the fuel of the iron and steel industry from charcoal to coal enormously increased the production of these metals. It also provided another incentive to coal production and made available the materials that were indispensable for the construction of steam engines and every other sophisticated form of machine. The transformation that began with a coke-smelting process in 1709 was carried further by the development of crucible steel in about 1740 and by the puddling and rolling process to produce wrought iron in 1784. The first development led to high-quality cast steel by fusion of the ingredients (wrought iron and charcoal, in carefully measured proportions) in sealed ceramic crucibles that could be heated in a coal-fired furnace. The second applied the principle of the reverberatory furnace, whereby the hot gases passed over the surface of the metal being heated rather than through it, thus greatly reducing the risk of contamination by impurities in the coal fuels, and the discovery that by puddling, or stirring, the molten metal and by passing it hot from the furnace to be hammered and rolled, the metal could be consolidated and the conversion of cast iron to wrought iron made completely effective.
Iron and steel
The result of this series of innovations was that the British iron and steel industry was freed from its reliance upon the forests as a source of charcoal and was encouraged to move toward the major coalfields. Abundant cheap iron thus became an outstanding feature of the early stages of the Industrial Revolution in Britain. Cast iron was available for bridge construction, for the framework of fireproof factories, and for other civil-engineering purposes such as Thomas Telford’s novel cast-iron aqueducts. Wrought iron was available for all manner of mechanical devices requiring strength and precision. Steel remained a comparatively rare metal until the second half of the 19th century, when the situation was transformed by the Bessemer and Siemens processes for manufacturing steel in bulk. Henry Bessemer took out the patent for his converter in 1856. It consisted of a large vessel charged with molten iron, through which cold air was blown. There was a spectacular reaction resulting from the combination of impurities in the iron with oxygen in the air, and when this subsided it left mild steel in the converter. Bessemer was virtually a professional inventor with little previous knowledge of the iron and steel industry; his process was closely paralleled by that of the American iron manufacturer William Kelly, who was prevented by bankruptcy from taking advantage of his invention. Meanwhile, the Siemens-Martin open-hearth process was introduced in 1864, utilizing the hot waste gases of cheap fuel to heat a regenerative furnace, with the initial heat transferred to the gases circulating round the large hearth in which the reactions within the molten metal could be carefully controlled to produce steel of the quality required. The open-hearth process was gradually refined and by the end of the 19th century had overtaken the Bessemer process in the amount of steel produced. The effect of these two processes was to make steel available in bulk instead of small-scale ingots of cast crucible steel, and thenceforward steel steadily replaced wrought iron as the major commodity of the iron and steel industry.
Low-grade ores
The transition to cheap steel did not take place without technical problems, one of the most difficult of which was the fact that most of the easily available low-grade iron ores in the world contain a proportion of phosphorus, which proved difficult to eliminate but which ruined any steel produced from them. The problem was solved by the British scientists S.G. Thomas and Percy Gilchrist, who invented the basic slag process, in which the furnace or converter was lined with an alkaline material with which the phosphorus could combine to produce a phosphatic slag; this, in turn, became an important raw material in the nascent artificial-fertilizer industry. The most important effect of this innovation was to make the extensive phosphoric ores of Lorraine and elsewhere available for exploitation. Among other things, therefore, it contributed significantly to the rise of the German heavy iron and steel industry in the Ruhr. Other improvements in British steel production were made in the late 19th century, particularly in the development of alloys for specialized purposes, but these contributed more to the quality than the quantity of steel and did not affect the shift away from Britain to continental Europe and North America of dominance in this industry. British production continued to increase, but by 1900 it had been overtaken by that of the United States and Germany.
Mechanical engineering
Closely linked with the iron and steel industry was the rise of mechanical engineering, brought about by the demand for steam engines and other large machines, and taking shape for the first time in the Soho workshop of Boulton and Watt in Birmingham, where the skills of the precision engineer, developed in manufacturing scientific instruments and small arms, were first applied to the construction of large industrial machinery. The engineering workshops that matured in the 19th century played a vital part in the increasing mechanization of industry and transport. Not only did they deliver the looms, locomotives, and other hardware in steadily growing quantities, but they also transformed the machine tools on which these machines were made. The lathe became an all-metal, power-driven machine with a completely rigid base and a slide rest to hold the cutting tool, capable of more sustained and vastly more accurate work than the hand- or foot-operated wooden-framed lathes that preceded it. Drilling and slotting machines, milling and planing machines, and a steam hammer invented by James Nasmyth (an inverted vertical steam engine with the hammer on the lower end of the piston rod), were among the machines devised or improved from earlier woodworking models by the new mechanical engineering industry. After the middle of the 19th century, specialization within the machinery industry became more pronounced, as some manufacturers concentrated on vehicle production while others devoted themselves to the particular needs of industries such as coal mining, papermaking, and sugar refining. This movement toward greater specialization was accelerated by the establishment of mechanical engineering in the other industrial nations, especially in Germany, where electrical engineering and other new skills made rapid progress, and in the United States, where labour shortages encouraged the development of standardization and mass-production techniques in fields as widely separated as agricultural machinery, small arms, typewriters, and sewing machines. Even before the coming of the bicycle, the automobile, and the airplane, therefore, the pattern of the modern engineering industry had been clearly established. The dramatic increases in engineering precision, represented by the machine designed by British mechanical engineer Sir Joseph Whitworth in 1856 for measuring to an accuracy of 0.000001 inch (even though such refinement was not necessary in everyday workshop practice), and the corresponding increase in the productive capacity of the engineering industry, acted as a continuing encouragement to further mechanical innovation.
Textiles
The industry that, probably more than any other, gave its character to the British Industrial Revolution was the cotton-textile industry. The traditional dates of the Industrial Revolution bracket the period in which the processes of cotton manufacture in Britain were transformed from those of a small-scale domestic industry scattered over the towns and villages of the South Pennines into those of a large-scale, concentrated, power-driven, mechanized, factory-organized, urban industry. The transformation was undoubtedly dramatic both to contemporaries and to posterity, and there is no doubting its immense significance in the overall pattern of British industrialization. But its importance in the history of technology should not be exaggerated. Certainly there were many interesting mechanical improvements, at least at the beginning of the transformation. The development of the spinning wheel into the spinning jenny, and the use of rollers and moving trolleys to mechanize spinning in the shape of the frame and the mule, respectively, initiated a drastic rise in the productivity of the industry. But these were secondary innovations in the sense that there were precedents for them in the experiments of the previous generation; that in any case the first British textile factory was the Derby silk mill built in 1719; and that the most far-reaching innovation in cotton manufacture was the introduction of steam power to drive carding machines, spinning machines, power looms, and printing machines. This, however, is probably to overstate the case, and the cotton innovators should not be deprived of credit for their enterprise and ingenuity in transforming the British cotton industry and making it the model for subsequent exercises in industrialization. Not only was it copied, belatedly and slowly, by the woolen-cloth industry in Britain, but wherever other nations sought to industrialize they tried to acquire British cotton machinery and the expertise of British cotton industrialists and artisans.
One of the important consequences of the rapid rise of the British cotton industry was the dynamic stimulus it gave to other processes and industries. The rising demand for raw cotton, for example, encouraged the plantation economy of the southern United States and the introduction of the cotton gin, an important contrivance for separating mechanically the cotton fibres from the seeds, husks, and stems of the plant.
Chemicals
In Britain the growth of the textile industry brought a sudden increase of interest in the chemical industry, because one formidable bottleneck in the production of textiles was the long time that was taken by natural bleaching techniques, relying on sunlight, rain, sour milk, and urine. The modern chemical industry was virtually called into being in order to develop more rapid bleaching techniques for the British cotton industry. Its first success came in the middle of the 18th century, when John Roebuck invented the method of mass producing sulfuric acid in lead chambers. The acid was used directly in bleaching, but it was also used in the production of more effective chlorine bleaches, and in the manufacture of bleaching powder, a process perfected by Charles Tennant at his St. Rollox factory in Glasgow in 1799. This product effectively met the requirements of the cotton-textile industry, and thereafter the chemical industry turned its attention to the needs of other industries, and particularly to the increasing demand for alkali in soap, glass, and a range of other manufacturing processes. The result was the successful establishment of the Leblanc soda process, patented by Nicolas Leblanc in France in 1791, for manufacturing sodium carbonate (soda) on a large scale; this remained the main alkali process used in Britain until the end of the 19th century, even though the Belgian Solvay process, which was considerably more economical, was replacing it elsewhere.
Innovation in the chemical industry shifted, in the middle of the 19th century, from the heavy chemical processes to organic chemistry. The stimulus here was less a specific industrial demand than the pioneering work of a group of German scientists on the nature of coal and its derivatives. Following their work, W.H. Perkin, at the Royal College of Chemistry in London, produced the first artificial dye from aniline in 1856. In the same period, the middle third of the 19th century, work on the qualities of cellulosic materials was leading to the development of high explosives such as nitrocellulose, nitroglycerine, and dynamite, while experiments with the solidification and extrusion of cellulosic liquids were producing the first plastics, such as celluloid, and the first artificial fibres, so-called artificial silk, or rayon. By the end of the century all these processes had become the bases for large chemical industries.
An important by-product of the expanding chemical industry was the manufacture of a widening range of medicinal and pharmaceutical materials as medical knowledge increased and drugs began to play a constructive part in therapy. The period of the Industrial Revolution witnessed the first real progress in medical services since the ancient civilizations. Great advances in the sciences of anatomy and physiology had had remarkably little effect on medical practice. In 18th-century Britain, however, hospital provision increased in quantity although not invariably in quality, while a significant start was made in immunizing people against smallpox culminating in Edward Jenner’s vaccination process of 1796, by which protection from the disease was provided by administering a dose of the much less virulent but related disease of cowpox. But it took many decades of use and further smallpox epidemics to secure its widespread adoption and thus to make it effective in controlling the disease. By this time Louis Pasteur and others had established the bacteriological origin of many common diseases and thereby helped to promote movements for better public health and immunization against many virulent diseases such as typhoid fever and diphtheria. Parallel improvements in anesthetics (beginning with Sir Humphry Davy’s discovery of nitrous oxide, or “laughing gas,” in 1799) and antiseptics were making possible elaborate surgery, and by the end of the century X-rays and radiology were placing powerful new tools at the disposal of medical technology, while the use of synthetic drugs such as the barbiturates and aspirin (acetylsalicylic acid) had become established.
Agriculture
The agricultural improvements of the 18th century had been promoted by people whose industrial and commercial interests made them willing to experiment with new machines and processes to improve the productivity of their estates. Under the same sort of stimuli, agricultural improvement continued into the 19th century and was extended to food processing in Britain and elsewhere. The steam engine was not readily adapted for agricultural purposes, yet ways were found of harnessing it to threshing machines and even to plows by means of a cable between powerful traction engines pulling a plow across a field. In the United States mechanization of agriculture began later than in Britain, but because of the comparative labour shortage it proceeded more quickly and more thoroughly. The McCormick reaper and the combine harvester were both developed in the United States, as were barbed wire and the food-packing and canning industries, Chicago becoming the centre for these processes. The introduction of refrigeration techniques in the second half of the 19th century made it possible to convey meat from Australia and Argentina to European markets, and the same markets encouraged the growth of dairy farming and market gardening, with distant producers such as New Zealand able to send their butter in refrigerated ships to wherever in the world it could be sold.
Civil engineering
For large civil-engineering works, the heavy work of moving earth continued to depend throughout this period on human labour organized by building contractors. But the use of gunpowder, dynamite, and steam diggers helped to reduce this dependence toward the end of the 19th century, and the introduction of compressed air and hydraulic tools also contributed to the lightening of drudgery. The latter two inventions were important in other respects, such as in mining engineering and in the operation of lifts, lock gates, and cranes. The use of a tunneling shield, to allow a tunnel to be driven through soft or uncertain rock strata, was pioneered by the French émigré engineer Marc Brunel in the construction of the first tunnel underneath the Thames River in London (1825–42), and the technique was adopted elsewhere. The iron bell or caisson was introduced for working below water level in order to lay foundations for bridges or other structures, and bridge building made great advances with the perfecting of the suspension bridge by the British engineers Thomas Telford and Isambard Kingdom Brunel and the German American engineer John Roebling and the development of the truss bridge, first in timber, then in iron. Wrought iron gradually replaced cast iron as a bridge-building material, although several distinguished cast-iron bridges survive, such as that erected at Ironbridge in Shropshire between 1777 and 1779, which has been fittingly described as the “Stonehenge of the Industrial Revolution.” The sections were cast at the Coalbrookdale furnace nearby and assembled by mortising and wedging on the model of a timber construction, without the use of bolts or rivets. The design was quickly superseded in other cast-iron bridges, but the bridge still stands as the first important structural use of cast iron. Cast iron became very important in the framing of large buildings, the elegant Crystal Palace of 1851 being an outstanding example. This was designed by the ingenious gardener-turned-architect Sir Joseph Paxton on the model of a greenhouse that he had built on the Chatsworth estate of the duke of Devonshire. Its cast-iron beams were manufactured by three different firms and tested for size and strength on the site. By the end of the 19th century, however, steel was beginning to replace cast iron as well as wrought iron, and reinforced concrete was being introduced. In water-supply and sewage-disposal works, civil engineering achieved some monumental successes, especially in the design of dams, which improved considerably in the period, and in long-distance piping and pumping.
Transport and communications
Transport and communications provide an example of a revolution within the Industrial Revolution, so completely were the modes transformed in the period 1750–1900. The first improvements in Britain came in roads and canals in the second half of the 18th century. Although of great economic importance, these were not of much significance in the history of technology, as good roads and canals had existed in continental Europe for at least a century before their adoption in Britain. A network of hard-surfaced roads was built in France in the 17th and early 18th centuries and copied in Germany. Pierre Trésaguet of France improved road construction in the late 18th century by separating the hard-stone wearing surface from the rubble substrata and providing ample drainage. Nevertheless, by the beginning of the 19th century, British engineers were beginning to innovate in both road- and canal-building techniques, with J.L. McAdam’s inexpensive and long-wearing road surface of compacted stones and Thomas Telford’s well-engineered canals. The outstanding innovation in transport, however, was the application of steam power, which occurred in three forms.
Steam locomotive
First was the evolution of the railroad: the combination of the steam locomotive and a permanent travel way of metal rails. Experiments in this conjunction in the first quarter of the 19th century culminated in the Stockton & Darlington Railway, opened in 1825, and a further five years of experience with steam locomotives led to the Liverpool and Manchester Railway, which, when it opened in 1830, constituted the first fully timetabled railway service with scheduled freight and passenger traffic relying entirely on the steam locomotive for traction. This railway was designed by George Stephenson, and the locomotives were the work of Stephenson and his son Robert, the first locomotive being the famous Rocket, which won a competition held by the proprietors of the railway at Rainhill, outside Liverpool, in 1829. The opening of the Liverpool and Manchester line may fairly be regarded as the inauguration of the railway era, which continued until World War I. During this time railways were built across all the countries and continents of the world, opening up vast areas to the markets of industrial society. Locomotives increased rapidly in size and power, but the essential principles remained the same as those established by the Stephensons in the early 1830s: horizontal cylinders mounted beneath a multitubular boiler with a firebox at the rear and a tender carrying supplies of water and fuel. This was the form developed from the Rocket, which had diagonal cylinders, being itself a stage in the transition from the vertical cylinders, often encased by the boiler, which had been typical of the earliest locomotives (except Trevithick’s Penydarren engine, which had a horizontal cylinder). Meanwhile, the construction of the permanent way underwent a corresponding improvement on that which had been common on the preceding tramroads: wrought-iron, and eventually steel, rails replaced the cast-iron rails, which cracked easily under a steam locomotive, and well-aligned track with easy gradients and substantial supporting civil-engineering works became a commonplace of the railroads of the world.
Road locomotive
The second form in which steam power was applied to transport was that of the road locomotive. There is no technical reason why this should not have enjoyed a success equal to that of the railway engine, but its development was so constricted by the unsuitability of most roads and by the jealousy of other road users that it achieved general utility only for heavy traction work and such duties as road rolling. The steam traction engine, which could be readily adapted from road haulage to power farm machines, was nevertheless a distinguished product of 19th-century steam technology.
Steamboats and ships
The third application was considerably more important, because it transformed marine transport. The initial attempts to use a steam engine to power a boat were made on the Seine River in France in 1775, and several experimental steamships were built by William Symington in Britain at the turn of the 19th century. The first commercial success in steam propulsion for a ship, however, was that of the American Robert Fulton, whose paddle steamer the “North River Steamboat,” commonly known as the Clermont after its first overnight port, plied between New York and Albany in 1807, equipped with a Boulton and Watt engine of the modified beam or side-lever type, with two beams placed alongside the base of the engine in order to lower the centre of gravity. A similar engine was installed in the Glasgow-built Comet, which was put in service on the Clyde in 1812 and was the first successful steamship in Europe. All the early steamships were paddle-driven, and all were small vessels suitable only for ferry and packet duties because it was long thought that the fuel requirements of a steamship would be so large as to preclude long-distance cargo carrying. The further development of the steamship was thus delayed until the 1830s, when I.K. Brunel began to apply his ingenious and innovating mind to the problems of steamship construction. His three great steamships each marked a leap forward in technique. The Great Western (launched 1837), the first built specifically for oceanic service in the North Atlantic, demonstrated that the proportion of space required for fuel decreased as the total volume of the ship increased. The Great Britain (launched 1843) was the first large iron ship in the world and the first to be screw-propelled; its return to the port of Bristol in 1970, after a long working life and abandonment to the elements, is a remarkable testimony to the strength of its construction. The Great Eastern (launched 1858), with its total displacement of 18,918 tons, was by far the largest ship built in the 19th century. With a double iron hull and two sets of engines driving both a screw and paddles, this leviathan was never an economic success, but it admirably demonstrated the technical possibilities of the large iron steamship. By the end of the century, steamships were well on the way to displacing the sailing ship on all the main trade routes of the world.
Printing and photography
Communications were equally transformed in the 19th century. The steam engine helped to mechanize and thus to speed up the processes of papermaking and printing. In the latter case the acceleration was achieved by the introduction of the high-speed rotary press and the Linotype machine for casting type and setting it in justified lines (i.e., with even right-hand margins). Printing, indeed, had to undergo a technological revolution comparable to the 15th-century invention of movable type to be able to supply the greatly increasing market for the printed word. Another important process that was to make a vital contribution to modern printing was discovered and developed in the 19th century: photography. The first photograph was taken in 1826 or 1827 by the French physicist J.N. Niepce, using a pewter plate coated with a form of bitumen that hardened on exposure. His partner L.-J.-M. Daguerre and the Englishman W.H. Fox Talbot adopted silver compounds to give light sensitivity, and the technique developed rapidly in the middle decades of the century. By the 1890s George Eastman in the United States was manufacturing cameras and celluloid photographic film for a popular market, and the first experiments with the cinema were beginning to attract attention.
Telegraphs and telephones
The great innovations in communications technology, however, derived from electricity. The first was the electric telegraph, invented or at least made into a practical proposition for use on the developing British railway system by two British inventors, Sir William Cooke and Sir Charles Wheatstone, who collaborated on the work and took out a joint patent in 1837. Almost simultaneously, the American inventor Samuel F.B. Morse devised the signaling code that was subsequently adopted all over the world. In the next quarter of a century the continents of the world were linked telegraphically by transoceanic cables, and the main political and commercial centers were brought into instantaneous communication. The telegraph system also played an important part in the opening up of the American West by providing rapid aid in the maintenance of law and order. The electric telegraph was followed by the telephone, invented by Alexander Graham Bell in 1876 and adopted quickly for short-range oral communication in the cities of America and at a somewhat more leisurely pace in those of Europe. About the same time, theoretical work on the electromagnetic properties of light and other radiation was beginning to produce astonishing experimental results, and the possibilities of wireless telegraphy began to be explored. By the end of the century, Guglielmo Marconi had transmitted messages over many miles in Britain and was preparing the apparatus with which he made the first transatlantic radio communication on December 12, 1901. The world was thus being drawn inexorably into a closer community by the spread of instantaneous communication.
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