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History of Technology — 4. The Industrial Revolution History of Technology — 4. The Industrial Revolution
Síntese da Encyclopaedia Britannica
(1750-1900)
Nota: para consultar as restantes partes da sínteseconsult no final desta parte e clicanos hyperlinks azuis para abrir os respectivosficheiros pdf History of Technology — 4. The Industrial Revolution IV. 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 forpurposes of understanding and instruction and because there were sufficientinnovations at the turn of the 18th and 19th centuries to justify the choice of this asone of the periods. The term is imprecise, however, because the IndustrialRevolution has no clearly defined beginning or end. Moreover, it is misleading if itcarries the implication of a once-for-all change from a “preindustrial” to a -postindustrial- society, because, as has been seen, the events of the traditionalIndustrial Revolution had been well prepared in a mounting tempo of industrial,commercial, and technological activity from about AD 1000 and led into a continuingacceleration of the processes of industrialization that is still proceeding in our owntime. The term Industrial Revolution must thus be employed with some care. It isused below to describe an extraordinary quickening in the rate of growth andchange, 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 arevery 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 tocontinental Europe and North America. Equally clearly, the Industrial Revolution thateventually transformed these parts of the Western world surpassed in magnitudethe achievements of Britain, and the process was carried further to change radicallythe socioeconomic life of the Far East, Africa, Latin America, and Australasia. Thereasons for this succession of events are complex, but they were implicit in theearlier account of the buildup toward rapid industrialization. Partly through goodfortune and partly through conscious effort, Britain by the early 18th century came topossess the combination of social needs and social resources that provided thenecessary preconditions of commercially successful innovation and a social systemcapable of sustaining and institutionalizing the processes of rapid technologicalchange once they had started. This section will therefore be concerned, in the firstplace, with events in Britain, although in discussing later phases of the period it willbe necessary to trace the way in which British technical achievements were diffusedand 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 poweravailable to industry and any other potential consumer were animate energy and thepower of wind and water, the only exception of any significance being theatmospheric steam engines that had been installed for pumping purposes, mainly incoal mines. It is to be emphasized that this use of steam power was exceptional and History of Technology — 4. The Industrial Revolution remained so for most industrial purposes until well into the 19th century. Steam didnot simply replace other sources of power: it transformed them. The same sort ofscientific inquiry that led to the development of the steam engine was also applied tothe traditional sources of inanimate energy, with the result that both waterwheelsand windmills were improved in design and efficiency. Numerous engineerscontributed to the refinement of waterwheel construction, and by the middle of the19th century new designs made possible increases in the speed of revolution of thewaterwheel 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 thesails pointed into the wind. Spring sails replaced the traditional canvas rig of thewindmill with the equivalent of a modern venetian blind, the shutters of which couldbe opened or closed, to let the wind pass through or to provide a surface uponwhich 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 controlledon all the sails simultaneously by a lever inside the mill connected by rod linkagesthrough the windshaft with the bar operating the movement of the shutters on eachsweep. The control could be made more fully automatic by hanging weights on thelever in the mill to determine the maximum wind pressure beyond which the shutterswould open and spill the wind. Conversely, counterweights could be attached tokeep the shutters in the open position. With these and other modifications, Britishwindmills adapted to the increasing demands on power technology. But the use ofwind power declined sharply in the 19th century with the spread of steam and theincreasing scale of power utilization. Windmills that had satisfactorily providedpower for small-scale industrial processes were unable to compete with theproduction 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 IndustrialRevolution. Little development took place in the Newcomen atmospheric engineuntil James Watt patented a separate condenser in 1769, but from that point onwardthe steam engine underwent almost continuous improvements for more than acentury. Watt's separate condenser was the outcome of his work on a model of aNewcomen engine that was being used in a University of Glasgow laboratory. Watt'sinspiration was to separate the two actions of heating the cylinder with hot steamand cooling it to condense the steam for every stroke of the engine. By keeping thecylinder permanently hot and the condenser permanently cold, a great economy onenergy used could be effected. This brilliantly simple idea could not be immediately History of Technology — 4. The Industrial Revolution incorporated in a full-scale engine because the engineering of such machines hadhitherto been crude and defective. The backing of a Birmingham industrialist,Matthew Boulton, with his resources of capital and technical competence, wasneeded to convert the idea into a commercial success. Between 1775 and 1800, theperiod over which Watt's patents were extended, the Boulton and Watt partnershipproduced some 500 engines, which despite their high cost in relation to aNewcomen engine were eagerly acquired by the tin-mining industrialists of Cornwalland other power users who badly needed a more economic and reliable source ofenergy.
During the quarter of a century in which Boulton and Watt exercised their virtual monopoly over the manufacture of improved steam engines, they introduced manyimportant refinements. Basically they converted the engine from a single-acting (i.e.,applying power only on the downward stroke of the piston) atmospheric pumpingmachine into a versatile prime mover that was double-acting and could be applied torotary motion, thus driving the wheels of industry. The rotary action engine wasquickly adopted by British textile manufacturer Sir Richard Arkwright for use in acotton mill, and although the ill-fated Albion Mill, at the southern end of BlackfriarsBridge in London, was burned down in 1791, when it had been in use for only fiveyears and was still incomplete, it demonstrated the feasibility of applying steampower to large-scale grain milling. Many other industries followed in exploring thepossibilities 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 Cornishengineer Richard Trevithick introduced higher steam pressures, achieving anunprecedented pressure of 145 pounds per square inch (10 kilograms per squarecentimetre) in 1802 with an experimental engine at Coalbrookdale, which workedsafely and efficiently. Almost simultaneously, the versatile American engineer OliverEvans built the first high-pressure steam engine in the United States, using, likeTrevithick, a cylindrical boiler with an internal fire plate and flue. High-pressuresteam engines rapidly became popular in America, partly as a result of Evans'initiative and partly because very few Watt-type low-pressure engines crossed theAtlantic. Trevithick quickly applied his engine to a vehicle, making the firstsuccessful steam locomotive for the Penydarren tramroad in South Wales in 1804.
The success, however, was technological rather than commercial because thelocomotive fractured the cast iron track of the tramway: the age of the railroad had toawait 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 thedevelopment of the large beam pumping engines with a complex sequence of valveactions, which became universally known as Cornish engines; their distinctivecharacteristic was the cutoff of steam injection before the stroke was complete inorder to allow the steam to do work by expanding. These engines were used all over History of Technology — 4. The Industrial Revolution the world for heavy pumping duties, often being shipped out and installed byCornish engineers. Trevithick himself spent many years improving pumping enginesin Latin America. Cornish engines, however, were probably most common inCornwall itself, where they were used in large numbers in the tin and copper miningindustries.
Another consequence of high-pressure steam was the practice of compounding, of using the steam twice or more at descending pressures before it was finallycondensed or exhausted. The technique was first applied by Arthur Woolf, aCornish mining engineer, who by 1811 had produced a very satisfactory andefficient compound beam engine with a high-pressure cylinder placed alongside thelow-pressure cylinder, with both piston rods attached to the same pin of the parallelmotion, 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 ofcompound beam engine, with the high-pressure cylinder on the opposite end of thebeam from the low-pressure cylinder, and working with a shorter stroke. Thisbecame a very popular design. Various other methods of compounding steamengines were adopted, and the practice became increasingly widespread; in thesecond half of the 19th century triple- or quadruple-expansion engines were beingused in industry and marine propulsion. By this time also the conventionalbeam-type vertical engine adopted by Newcomen and retained by Watt began to bereplaced by horizontal-cylinder designs. Beam engines remained in use for somepurposes until the eclipse of the reciprocating steam engine in the 20th century, andother types of vertical engine remained popular, but for both large and small dutiesthe 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 highrotational speed to make the dynamos function efficiently. Such speeds werebeyond the range of the normal reciprocating engine (i.e., with a piston movingbackward and forward in a cylinder). Designers began to investigate the possibilitiesof 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 firstcategory, one solution was to enclose the working parts of the engine and force alubricant around them under pressure. The Willans engine design, for instance, wasof this type and was widely adopted in early British power stations. Anotherimportant modification in the reciprocating design was the uniflow engine, whichincreased efficiency by exhausting steam from ports in the centre of the cylinderinstead of requiring it to change its direction of flow in the cylinder with everymovement 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 constituteda 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 increasingsize (to allow for the expansion of the steam) the energy of the steam was convertedto very rapid circular motion, which was ideal for generating electricity. Manyrefinements have since been made in turbine construction and the size of turbines History of Technology — 4. The Industrial Revolution has been vastly increased, but the basic principles remain the same, and thismethod still provides the main source of electric power except in those areas inwhich the mountainous terrain permits the economic generation of hydroelectricpower by water turbines. Even the most modern nuclear power plants use steamturbines because technology has not yet solved the problem of transforming nuclearenergy directly into electricity. In marine propulsion, too, the steam turbine remainsan important source of power despite competition from the internal-combustionengine.
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 byan international collection of scientists including Benjamin Franklin of Pennsylvania,Alessandro Volta of the University of Pavia, Italy, and Michael Faraday of Britain. Itwas the latter who had demonstrated the nature of the elusive relationship betweenelectricity and magnetism in 1831, and his experiments provided the point ofdeparture for both the mechanical generation of electric current, previously availableonly from chemical reactions within voltaic piles or batteries, and the utilization ofsuch current in electric motors. Both the mechanical generator and the motordepend on the rotation of a continuous coil of conducting wire between the poles ofa strong magnet: turning the coil produces a current in it, while passing a currentthrough the coil causes it to turn. Both generators and motors underwent substantialdevelopment in the middle decades of the 19th century. In particular, French,German, Belgian, and Swiss engineers evolved the most satisfactory forms ofarmature (the coil of wire) and produced the dynamo, which made the large-scalegeneration 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 notimmediately obvious. But in continental Europe and North America there was morescope for experiment. In the United States Thomas Edison applied his inventivegenius to finding fresh uses for electricity, and his development of thecarbon-filament lamp showed how this form of energy could rival gas as a domesticilluminant. The problem had been that electricity had been used successfully forlarge installations such as lighthouses in which arc lamps had been powered bygenerators on the premises, but no way of subdividing the electric light into manysmall units had been devised. The principle of the filament lamp was that a thinconductor could be made incandescent by an electric current provided that it wassealed in a vacuum to keep it from burning out. Edison and the English chemist SirJoseph Swan experimented with various materials for the filament and both chosecarbon. The result was a highly successful small lamp, which could be varied in sizefor any sort of requirement. It is relevant that the success of the carbon-filamentlamp did not immediately mean the supersession of gas lighting. Coal gas had firstbeen used for lighting by William Murdock at his home in Redruth, Cornwall, where History of Technology — 4. The Industrial Revolution he was the agent for the Boulton and Watt company, in 1792. When he moved tothe headquarters of the firm at Soho in Birmingham in 1798, Matthew Boultonauthorized him to experiment in lighting the buildings there by gas, and gas lightingwas subsequently adopted by firms and towns all over Britain in the first half of the19th century. Lighting was normally provided by a fishtail jet of burning gas, butunder the stimulus of competition from electric lighting the quality of gas lighting wasgreatly enhanced by the invention of the gas mantle. Thus improved, gas lightingremained popular for some forms of street lighting until the middle of the 20thcentury.
Lighting alone could not provide an economical market for electricity because its use was confined to the hours of darkness. Successful commercial generationdepended upon the development of other uses for electricity, and particularly onelectric traction. The popularity of urban electric tramways and the adoption ofelectric traction on subway systems such as the London Underground thuscoincided with the widespread construction of generating equipment in the late1880s and 1890s. The subsequent spread of this form of energy is one of the mostremarkable technological success stories of the 20th century, but most of the basictechniques of generation, distribution, and utilization had been mastered by the endof 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 bywater, steam, or internal combustion. The internal-combustion engine is a primemover, and it emerged in the 19th century as a result both of greater scientificunderstanding of the principles of thermodynamics and of a search by engineers fora substitute for steam power in certain circumstances. In an internal-combustionengine the fuel is burned in the engine: the cannon provided an early model of asingle-stroke engine; and several persons had experimented with gunpowder as ameans of driving a piston in a cylinder. The major problem was that of finding asuitable fuel, and the secondary problem was that of igniting the fuel in an enclosedspace to produce an action that could be easily and quickly repeated. The firstproblem 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 maintainignition evenly. The first successful gas engine was made by Étienne Lenoir in Parisin 1859. It was modeled closely on a horizontal steam engine, with an explosivemixture of gas and air ignited by an electric spark on alternate sides of the pistonwhen it was in midstroke position. Although technically satisfactory, the engine wasexpensive to operate, and it was not until the refinement introduced by the Germaninventor Nikolaus Otto in 1878 that the gas engine became a commercial success.
Otto adopted the four-stroke cycle of induction-compression-firing-exhaust that hasbeen known by his name ever since. Gas engines became extensively used for History of Technology — 4. The Industrial Revolution small industrial establishments, which could thus dispense with the upkeep of aboiler 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, dependingon a piped supply of town gas, any more than by the steam engine, with its need fora cumbersome boiler; but, by using alternative fuels derived from oil, theinternal-combustion engine took to wheels, with momentous consequences.
Bituminous deposits had been known in Southwest Asia from antiquity and hadbeen worked for building material, illuminants, and medicinal products. Thewestward expansion of settlement in America, with many homesteads beyond therange of city gas supplies, promoted the exploitation of the easily available sourcesof crude oil for the manufacture of kerosene (paraffin). In 1859 the oil industry tookon new significance when Edwin L. Drake bored successfully through 69 feet (21metres) of rock to strike oil in Pennsylvania, thus inaugurating the search for andexploitation of the deep oil resources of the world. While world supplies of oilexpanded dramatically, the main demand was at first for the kerosene, the middlefraction distilled from the raw material, which was used as the fuel in oil lamps. Themost volatile fraction of the oil, gasoline, remained an embarrassing waste productuntil it was discovered that this could be burned in a light internal-combustionengine; the result was an ideal prime mover for vehicles. The way was prepared forthis development by the success of oil engines burning cruder fractions of oil.
Kerosene-burning oil engines, modeled closely on existing gas engines, hademerged in the 1870s, and by the late 1880s engines using the vapour of heavy oilin a jet of compressed air and working on the Otto cycle had become an attractiveproposition 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 fromthermodynamic principles of minimizing heat losses, Diesel devised an engine inwhich the very high compression of the air in the cylinder secured the spontaneousignition of the oil when it was injected in a carefully determined quantity. Thisensured high thermal efficiency, but it also made necessary a heavy structurebecause of the high compression maintained, and also a rather rough performanceat low speeds compared with other oil engines. It was therefore not immediatelysuitable for locomotive purposes, but Diesel went on improving his engine and in the20th 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 GottliebDaimler and Carl Benz equipped the first motorcycle and the first motorcarrespectively with engines of their own design in 1885. Benz's -horseless carriage-became the prototype of the modern automobile, the development and History of Technology — 4. The Industrial Revolution consequences of which can be more conveniently considered in relation to therevolution 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 theinnovators in internal combustion were continental Europeans and Americans. Thetransition, indeed, reflects the general change in international leadership in theIndustrial Revolution, with Britain being gradually displaced from its position ofunchallenged superiority in industrialization and technological innovation. A similartransition occurred in the theoretical understanding of heat engines: it was the workof the Frenchman Sadi Carnot and other scientific investigators that led to the newscience of thermodynamics, rather than that of the British engineers who had mostpractical 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 representthe only significant developments in this field during the Industrial Revolution.
Rather, the success of these machines stimulated speculation about alternativesources of power, and in at least one case achieved a success the fullconsequences 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 enginedepends 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 theexposition of the laws of thermodynamics, Stirling had devised a cycle of heattransfer that was ingenious and economical. Various constructional problems limitedthe size of hot-air engines to very small units, so that although they were widelyused for driving fans and similar light duties before the availability of the electricmotor, they did not assume great technological significance. But the economy andcomparative cleanness of the hot-air engine were making it once more the subject ofintensive 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 fuelstimulated the coal industry, which had already grown rapidly by the beginning ofthe 18th century, into continuing expansion and innovation. The steam engine,which enormously increased the need for coal, contributed significantly towardobtaining it by providing more efficient mine pumps and, eventually, improvedventilating equipment. Other inventions such as that of the miners' safety lamphelped to improve working conditions, although the immediate consequence of itsintroduction in 1816 was to persuade mineowners to work dangerous seams, whichhad thitherto been regarded as inaccessible. The principle of the lamp was that theflame 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 coalmines until the advent of electric battery lamps. With these improvements, together History of Technology — 4. The Industrial Revolution with the simultaneous revolution in the transport system, British coal productionincreased steadily throughout the 19th century. The other important fuel for the newprime movers was petroleum, and the rapid expansion of its production has alreadybeen mentioned. In the hands of John D. Rockefeller and his Standard Oilorganization it grew into a vast undertaking in the United States after the end of theCivil War, but the oil-extraction industry was not so well organized elsewhere untilthe 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 forworking with iron and steel was one of the outstanding British achievements of theIndustrial Revolution. The essential characteristic of this achievement was thatchanging the fuel of the iron and steel industry from charcoal to coal enormouslyincreased the production of these metals. It also provided another incentive to coalproduction and made available the materials that were indispensable for theconstruction of steam engines and every other sophisticated form of machine. Thetransformation that began with a coke-smelting process in 1709 was carried furtherby the development of crucible steel in about 1740 and by the puddling and rollingprocess to produce wrought iron in 1784. The first development led to high-qualitycast steel by fusion of the ingredients (wrought iron and charcoal, in carefullymeasured proportions) in sealed ceramic crucibles that could be heated in acoal-fired furnace. The second applied the principle of the reverberatory furnace,whereby the hot gases passed over the surface of the metal being heated ratherthan through it, thus greatly reducing the risk of contamination by impurities in thecoal fuels, and the discovery that by puddling, or stirring, the molten metal and bypassing it hot from the furnace to be hammered and rolled, the metal could beconsolidated and the conversion of cast iron to wrought iron made completelyeffective.
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 wasencouraged to move toward the major coalfields. Abundant cheap iron thus becamean outstanding feature of the early stages of the Industrial Revolution in Britain.
Cast iron was available for bridge construction, for the framework of fireprooffactories, and for other civil-engineering purposes such as Thomas Telford's novelcast-iron aqueducts. Wrought iron was available for all manner of mechanicaldevices requiring strength and precision. Steel remained a comparatively rare metaluntil the second half of the 19th century, when the situation was transformed by the History of Technology — 4. The Industrial Revolution Bessemer and Siemens processes for manufacturing steel in bulk. Henry Bessemertook out the patent for his converter in 1856. It consisted of a large vessel chargedwith molten iron, through which cold air was blown. There was a spectacularreaction resulting from the combination of impurities in the iron with oxygen in theair, and when this subsided it left mild steel in the converter. Bessemer was virtuallya professional inventor with little previous knowledge of the iron and steel industry;his process was closely paralleled by that of the American iron manufacturer WilliamKelly, 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 theinitial heat transferred to the gases circulating round the large hearth in which thereactions within the molten metal could be carefully controlled to produce steel ofthe quality required. The open-hearth process was gradually refined and by the endof the 19th century had overtaken the Bessemer process in the amount of steelproduced. The effect of these two processes was to make steel available in bulkinstead of small-scale ingots of cast crucible steel, and thenceforward steel steadilyreplaced 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-gradeiron ores in the world contain a proportion of phosphorus, which proved difficult toeliminate but which ruined any steel produced from them. The problem was solvedby the British scientists S.G. Thomas and Percy Gilchrist, who invented the basicslag process, in which the furnace or converter was lined with an alkaline materialwith which the phosphorus could combine to produce a phosphatic slag; this, in turn,became an important raw material in the nascent artificial-fertilizer industry. Themost important effect of this innovation was to make the extensive phosphoric oresof Lorraine and elsewhere available for exploitation. Among other things, therefore,it contributed significantly to the rise of the German heavy iron and steel industry inthe Ruhr. Other improvements in British steel production were made in the late 19thcentury, particularly in the development of alloys for specialized purposes, but thesecontributed more to the quality than the quantity of steel and did not affect the shiftaway from Britain to continental Europe and North America of dominance in thisindustry. British production continued to increase, but by 1900 it had been overtakenby 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 largemachines, and taking shape for the first time in the Soho workshop of Boulton andWatt in Birmingham, where the skills of the precision engineer, developed in History of Technology — 4. The Industrial Revolution manufacturing scientific instruments and small arms, were first applied to theconstruction of large industrial machinery. The engineering workshops that maturedin the 19th century played a vital part in the increasing mechanization of industryand transport. Not only did they deliver the looms, locomotives, and other hardwarein steadily growing quantities, but they also transformed the machine tools on whichthese machines were made. The lathe became an all-metal, power-driven machinewith a completely rigid base and a slide rest to hold the cutting tool, capable of moresustained and vastly more accurate work than the hand- or foot-operatedwooden-framed lathes that preceded it. Drilling and slotting machines, milling andplaning machines, and a steam hammer invented by James Nasmyth (an invertedvertical steam engine with the hammer on the lower end of the piston rod), wereamong the machines devised or improved from earlier woodworking models by thenew mechanical engineering industry. After the middle of the 19th century,specialization within the machinery industry became more pronounced, as somemanufacturers concentrated on vehicle production while others devoted themselvesto the particular needs of industries such as coal mining, papermaking, and sugarrefining. This movement toward greater specialization was accelerated by theestablishment of mechanical engineering in the other industrial nations, especially inGermany, where electrical engineering and other new skills made rapid progress,and in the United States, where labour shortages encouraged the development ofstandardization and mass-production techniques in fields as widely separated asagricultural machinery, small arms, typewriters, and sewing machines. Even beforethe coming of the bicycle, the automobile, and the airplane, therefore, the pattern ofthe modern engineering industry had been clearly established. The dramaticincreases in engineering precision, represented by the machine designed by Britishmechanical engineer Sir Joseph Whitworth in 1856 for measuring to an accuracy of0.000001 inch (even though such refinement was not necessary in everydayworkshop practice), and the corresponding increase in the productive capacity ofthe engineering industry, acted as a continuing encouragement to furthermechanical 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 theIndustrial Revolution bracket the period in which the processes of cottonmanufacture in Britain were transformed from those of a small-scale domesticindustry scattered over the towns and villages of the South Pennines into those of alarge-scale, concentrated, power-driven, mechanized, factory-organized, urbanindustry. The transformation was undoubtedly dramatic both to contemporaries andto posterity, and there is no doubting its immense significance in the overall patternof British industrialization. But its importance in the history of technology should notbe exaggerated. Certainly there were many interesting mechanical improvements, atleast at the beginning of the transformation. The development of the spinning wheel History of Technology — 4. The Industrial Revolution into the spinning jenny, and the use of rollers and moving trolleys to mechanizespinning in the shape of the frame and the mule, respectively, initiated a drastic risein the productivity of the industry. But these were secondary innovations in thesense that there were precedents for them in the experiments of the previousgeneration; that in any case the first British textile factory was the Derby silk millbuilt in 1719; and that the most far-reaching innovation in cotton manufacture wasthe introduction of steam power to drive carding machines, spinning machines,power looms, and printing machines. This, however, is probably to overstate thecase, and the cotton innovators should not be deprived of credit for their enterpriseand ingenuity in transforming the British cotton industry and making it the model forsubsequent exercises in industrialization. Not only was it copied, belatedly andslowly, by the woolen-cloth industry in Britain, but wherever other nations sought toindustrialize they tried to acquire British cotton machinery and the expertise ofBritish 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 risingdemand for raw cotton, for example, encouraged the plantation economy of thesouthern United States and the introduction of the cotton gin, an importantcontrivance for separating mechanically the cotton fibres from the seeds, husks, andstems 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 oftextiles was the long time that was taken by natural bleaching techniques, relying onsunlight, rain, sour milk, and urine. The modern chemical industry was virtuallycalled into being in order to develop more rapid bleaching techniques for the Britishcotton industry. Its first success came in the middle of the 18th century, when JohnRoebuck 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 ofmore effective chlorine bleaches, and in the manufacture of bleaching powder, aprocess perfected by Charles Tennant at his St. Rollox factory in Glasgow in 1799.
This product effectively met the requirements of the cotton-textile industry, andthereafter 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 ofother manufacturing processes. The result was the successful establishment of theLeblanc soda process, patented by Nicolas Leblanc in France in 1791, formanufacturing sodium carbonate (soda) on a large scale; this remained the mainalkali process used in Britain until the end of the 19th century, even though theBelgian Solvay process, which was considerably more economical, was replacing itelsewhere.
History of Technology — 4. The Industrial Revolution 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 aspecific industrial demand than the pioneering work of a group of German scientistson the nature of coal and its derivatives. Following their work, W.H. Perkin, at theRoyal College of Chemistry in London, produced the first artificial dye from aniline in1856. In the same period, the middle third of the 19th century, work on the qualitiesof cellulosic materials was leading to the development of high explosives such asnitrocellulose, nitroglycerine, and dynamite, while experiments with the solidificationand 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 thecentury 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 medicalknowledge increased and drugs began to play a constructive part in therapy. Theperiod of the Industrial Revolution witnessed the first real progress in medicalservices since the ancient civilizations. Great advances in the sciences of anatomyand physiology had had remarkably little effect on medical practice. In 18th-centuryBritain, however, hospital provision increased in quantity although not invariably inquality, while a significant start was made in immunizing people against smallpoxculminating in Edward Jenner's vaccination process of 1796, by which protectionfrom the disease was provided by administering a dose of the much less virulent butrelated disease of cowpox. But it took many decades of use and further smallpoxepidemics to secure its widespread adoption and thus to make it effective incontrolling the disease. By this time Louis Pasteur and others had established thebacteriological origin of many common diseases and thereby helped to promotemovements for better public health and immunization against many virulentdiseases such as typhoid fever and diphtheria. Parallel improvements in anesthetics(beginning with Sir Humphry Davy's discovery of nitrous oxide, or -laughing gas,- in1799) and antiseptics were making possible elaborate surgery, and by the end ofthe century X rays and radiology were placing powerful new tools at the disposal ofmedical technology, while the use of synthetic drugs such as the barbiturates andaspirin (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 newmachines and processes to improve the productivity of their estates. Under thesame sort of stimuli, agricultural improvement continued into the 19th century andwas extended to food processing in Britain and elsewhere. The steam engine wasnot readily adapted for agricultural purposes, yet ways were found of harnessing itto threshing machines and even to plows by means of a cable between powerfultraction engines pulling a plow across a field. In the United States mechanization ofagriculture began later than in Britain, but because of the comparative labour History of Technology — 4. The Industrial Revolution shortage it proceeded more quickly and more thoroughly. The McCormick reaperand the combine harvester were both developed in the United States, as werebarbed wire and the food-packing and canning industries, Chicago becoming thecentre for these processes. The introduction of refrigeration techniques in thesecond half of the 19th century made it possible to convey meat from Australia andArgentina to European markets, and the same markets encouraged the growth ofdairy farming and market gardening, with distant producers such as New Zealandable to send their butter in refrigerated ships to wherever in the world it could besold.
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 thisdependence toward the end of the 19th century, and the introduction of compressedair and hydraulic tools also contributed to the lightening of drudgery. The latter twoinventions were important in other respects, such as in mining engineering and inthe operation of lifts, lock gates, and cranes. The use of a tunneling shield, to allowa tunnel to be driven through soft or uncertain rock strata, was pioneered by theFrench émigré engineer Marc Brunel in the construction of the first tunnelunderneath the Thames River in London (1825-42), and the technique was adoptedelsewhere. The iron bell or caisson was introduced for working below water level inorder to lay foundations for bridges or other structures, and bridge building madegreat advances with the perfecting of the suspension bridge-by the British engineersThomas Telford and Isambard Kingdom Brunel and the German-American engineerJohn 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, althoughseveral distinguished cast-iron bridges survive, such as that erected at Ironbridge inShropshire between 1777 and 1779, which has been fittingly described as the -Stonehenge of the Industrial Revolution.- The sections were cast at theCoalbrookdale furnace nearby and assembled by mortising and wedging on themodel of a timber construction, without the use of bolts or rivets. The design wasquickly superseded in other cast-iron bridges, but the bridge still stands as the firstimportant structural use of cast iron. Cast iron became very important in the framingof large buildings, the elegant Crystal Palace of 1851 being an outstandingexample. This was designed by the ingenious gardener-turned-architect Sir JosephPaxton on the model of a greenhouse that he had built on the Chatsworth estate ofthe Duke of Devonshire. Its cast-iron beams were manufactured by three differentfirms 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, andreinforced concrete was being introduced. In water-supply and sewage-disposalworks, civil engineering achieved some monumental successes, especially in the History of Technology — 4. The Industrial Revolution design of dams, which improved considerably in the period, and in long-distancepiping 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 halfof the 18th century. Although of great economic importance, these were not of muchsignificance in the history of technology, as good roads and canals had existed incontinental Europe for at least a century before their adoption in Britain. A networkof hard-surfaced roads was built in France in the 17th and early 18th centuries andcopied in Germany. Pierre Trésaguet of France improved road construction in thelate 18th century by separating the hard-stone wearing surface from the rubblesubstrata and providing ample drainage. Nevertheless, by the beginning of the 19thcentury, British engineers were beginning to innovate in both road- andcanal-building techniques, with J.L. McAdam's inexpensive and long-wearing roadsurface of compacted stones and Thomas Telford's well-engineered canals. Theoutstanding 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 firstquarter of the 19th century culminated in the Stockton & Darlington Railway, openedin 1825, and a further five years of experience with steam locomotives led to theLiverpool and Manchester Railway, which, when it opened in 1830, constituted thefirst fully timetabled railway service with scheduled freight and passenger trafficrelying entirely on the steam locomotive for traction. This railway was designed byGeorge Stephenson, and the locomotives were the work of Stephenson and his sonRobert, the first locomotive being the famous Rocket, which won a competition heldby the proprietors of the railway at Rainhill, outside Liverpool, in 1829. The openingof the Liverpool and Manchester line may fairly be regarded as the inauguration ofthe Railway Era, which continued until World War I. During this time railways werebuilt across all the countries and continents of the world, opening up vast areas tothe markets of industrial society. Locomotives increased rapidly in size and power,but the essential principles remained the same as those established by theStephensons in the early 1830s: horizontal cylinders mounted beneath amultitubular boiler with a firebox at the rear and a tender carrying supplies of waterand fuel. This was the form developed from the Rocket, which had diagonalcylinders, being itself a stage in the transition from the vertical cylinders, oftenencased by the boiler, which had been typical of the earliest locomotives (exceptTrevithick's Penydarren engine, which had a horizontal cylinder). Meanwhile, the History of Technology — 4. The Industrial Revolution construction of the permanent way underwent a corresponding improvement on thatwhich had been common on the preceding tramroads: wrought-iron, and eventuallysteel, rails replaced the cast-iron rails, which cracked easily under a steamlocomotive, and well-aligned track with easy gradients and substantial supportingcivil-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 asuccess equal to that of the railway engine, but its development was so constrictedby the unsuitability of most roads and by the jealousy of other road users that itachieved 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 topower farm machines, was nevertheless a distinguished product of 19th-centurysteam 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 weremade on the Seine River in France in 1775, and several experimental steamshipswere built by William Symington in Britain at the turn of the 19th century. The firstcommercial success in steam propulsion for a ship, however, was that of theAmerican Robert Fulton, whose paddle steamer the -North River Steamboat,-commonly known as the Clermont after its first overnight port, plied between NewYork and Albany in 1807, equipped with a Boulton and Watt engine of the modifiedbeam or side-lever type, with two beams placed alongside the base of the engine inorder to lower the centre of gravity. A similar engine was installed in theGlasgow-built Comet, which was put in service on the Clyde in 1812 and was thefirst 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 waslong thought that the fuel requirements of a steamship would be so large as topreclude long-distance cargo carrying. The further development of the steamshipwas thus delayed until the 1830s, when I.K. Brunel began to apply his ingenious andinnovating mind to the problems of steamship construction. His three greatsteamships each marked a leap forward in technique. The Great Western (launched1837), the first built specifically for oceanic service in the North Atlantic,demonstrated that the proportion of space required for fuel decreased as the totalvolume of the ship increased. The Great Britain (launched 1843) was the first largeiron ship in the world and the first to be screw-propelled; its return to the port ofBristol in 1970, after a long working life and abandonment to the elements, is aremarkable 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 History of Technology — 4. The Industrial Revolution ship built in the 19th century. With a double iron hull and two sets of engines drivingboth a screw and paddles, this leviathan was never an economic success, but itadmirably demonstrated the technical possibilities of the large iron steamship. Bythe end of the century, steamships were well on the way to displacing the sailingship 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 andprinting. In the latter case the acceleration was achieved by the introduction of thehigh-speed rotary press and the Linotype machine for casting type and setting it injustified lines (i.e., with even right-hand margins). Printing, indeed, had to undergo atechnological revolution comparable to the 15th-century invention of movable typeto be able to supply the greatly increasing market for the printed word. Anotherimportant process that was to make a vital contribution to modern printing wasdiscovered and developed in the 19th century: photography. The first photographwas taken in 1826 or 1827 by the French physicist J.N. Niepce, using a pewter platecoated 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 givelight sensitivity, and the technique developed rapidly in the middle decades of thecentury. By the 1890s George Eastman in the United States was manufacturingcameras and celluloid photographic film for a popular market, and the firstexperiments 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 apractical proposition for use on the developing British railway system by two Britishinventors, Sir William Cooke and Sir Charles Wheatstone, who collaborated on thework and took out a joint patent in 1837. Almost simultaneously, the Americaninventor Samuel F.B. Morse devised the signaling code that was subsequentlyadopted all over the world. In the next quarter of a century the continents of theworld were linked telegraphically by transoceanic cables, and the main political andcommercial centres were brought into instantaneous communication. The telegraphsystem also played an important part in the opening up of the American West byproviding rapid aid in the maintenance of law and order. The electric telegraph wasfollowed by the telephone, invented by Alexander Graham Bell in 1876 and adoptedquickly for short-range oral communication in the cities of America and at asomewhat more leisurely pace in those of Europe. About the same time, theoreticalwork on the electromagnetic properties of light and other radiation was beginning toproduce astonishing experimental results, and the possibilities of wirelesstelegraphy began to be explored. By the end of the century, Guglielmo Marconi had History of Technology — 4. The Industrial Revolution transmitted messages over many miles in Britain and was preparing the apparatuswith which he made the first transatlantic radio communication on Dec. 12, 1901.
The world was thus being drawn inexorably into a closer community by the spread ofinstantaneous communication.
Military technology
One area of technology was not dramatically influenced by the application of steam or electricity by the end of the 19th century: military technology. Although thesize of armies increased between 1750 and 1900, there were few major innovationsin techniques, except at sea where naval architecture rather reluctantly accepted theadvent of the iron steamship and devoted itself to matching ever-increasingfirepower with the strength of the armour plating on the hulls. The quality of artilleryand of firearms improved with the new high explosives that became available in themiddle of the 19th century, but experiments such as the three-wheeled iron guncarriage, invented by the French army engineer Nicolas Cugnot in 1769, whichcounts as the first steam-powered road vehicle, did not give rise to any confidencethat steam could be profitably used in battle. Railroads and the electric telegraphwere put to effective military use, but in general it is fair to say that the 19th centuryput remarkably little of its tremendous and innovative technological effort intodevices for war.
In the course of its dynamic development between 1750 and 1900, important things happened to technology itself. In the first place, it became self-conscious.
This change is sometimes characterized as one from a craft-based technology toone based on science, but this is an oversimplification. What occurred was rather anincrease in the awareness of technology as a socially important function. It isapparent in the growing volume of treatises on technological subjects from the 16thcentury onward and in the rapid development of patent legislation to protect theinterests of technological innovators. It is apparent also in the development oftechnical education, uneven at first, being confined to the French polytechnics andspreading thence to Germany and North America but reaching even Britain, whichhad been most opposed to its formal recognition as part of the structure ofeducation, by the end of the 19th century. Again, it is apparent in the growth ofprofessional associations for engineers and for other specialized groups oftechnologists.
Second, by becoming self-conscious, technology attracted attention in a way it had never done before, and vociferous factions grew up to praise it as themainspring of social progress and the development of democracy or to criticize it asthe bane of modern man, responsible for the harsh discipline of the -dark Satanicmills- and the tyranny of the machine and the squalor of urban life. It was clear bythe end of the 19th century that technology was an important feature in industrialsociety and that it was likely to become more so. Whatever was to happen in the History of Technology — 4. The Industrial Revolution future, technology had come of age and had to be taken seriously as a formativefactor of the utmost significance in the continuing development of civilization.
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Índice geral das 6 partes que constituem o artigo
Social involvement in technological advancesModes of technological transmission The beginnings - Stone Age technology (to c. 3000 BC) Earliest communitiesThe Neolithic RevolutionStonePower Tools and weaponsBuilding techniquesManufacturing Craftsmen and scientistsCopper and bronzeIrrigationUrban manufacturingBuildingTransmitting knowledge Technological achievements of Greece and Rome (500 BC-AD 500) The mastery of ironMechanical contrivancesAgricultureBuildingOther fields of technology Power sourcesAgriculture and craftsArchitectureMilitary technology TransportCommunications The emergence of Western technology (1500-1750)The RenaissanceThe steam engine History of Technology — 4. The Industrial Revolution Metallurgy and mining New commoditiesAgricultureConstruction WindmillsSteam engines ElectricityInternal-combustion enginePetroleum Mechanical engineeringTextilesChemicalsAgricultureCivil engineeringTransport and communications Steam locomotiveRoad locomotiveSteamboats and shipsPrinting and photographyTelegraphs and telephones Gas-turbine engine PetroleumElectricityAtomic power Improvements in iron and steelBuilding materialsPlasticsSynthetic fibresSynthetic rubberPharmaceuticals and medical technology Food and agricultureCivil engineeringTransportationCommunicationsMilitary technology History of Technology — 4. The Industrial Revolution Automation and the computerFood productionCivil engineeringTransport and communicationsMilitary technologySpace exploration Science and technologyCriticisms of technologyThe technological dilemma Nuclear technologyPopulation explosionEcological balance Interactions between society and technologyThe putative autonomy of technologyTechnology and education

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