An Encyclopedia of the History of Technology part 99 potx

PART FIVE: TECHNOLOGY AND SOCIETY 962 oil-pressure systems for automobile braking and many other power- transmission applications. Another form of power-transmission which has made a contribution to public services has been compressed air. Pneumatic devices in the shape of bellows have been familiar to craftsmen from antiquity, but little general use was made of them until the twentieth century, when they became very valuable tools in the construction industry and in mining, and in various forms of machine tool. They have also provided an essential part of the modern jet engine in aircraft, and they have become familiar to motorists the world over as a means of inflating pneumatic tyres. They have been particularly valuable in deep-mining processes because they do not cause pollution of the air supply and they minimize the danger of accidents from sparking or short-circuiting. The facility for transmitting power over long distances through flexible hosing has made pneumatic power convenient for many heavy but portable tools such as the drills used in constructional work. With a compressor coupled to a small diesel engine, air-powered drills have become a familiar feature of modern roadworks, As with hydraulic systems, the compressed medium is used to drive a piston or a ram which can then deliver a reciprocating action or which can be readily converted to rotary movement. It is less suited than hydraulic power to large-scale applications and has not been popular for municipal public services, but a system of underground compressed air pipes was installed in Paris in the 1880s, carrying power to pneumatic devices in various parts of the city. WASTE DISPOSAL Modern life generates many forms of waste, and important public services are devoted to disposing of them. The water-borne removal of organic waste has already been considered, because this is so closely related to the provision of a constant supply of fresh water. Other forms of waste removal can be more episodic. Thus, industrial and domestic garbage is collected regularly in modern towns and subjected to various forms of processing to recover metals, glass, and other reusable materials. The remainder is usually pulverized and compacted before being disposed of by emptying into holes such as those left by old quarrying operations, or dumped from barges into river estuaries from which it can be dispersed by the movement of the tides. A few of the most progressive public authorities in Sweden and elsewhere have installed the expensive plant necessary to burn such garbage, using it as a fuel to heat water and generate power. There is little doubt that this is the most desirable solution to the problem posed by the disposal of constantly growing masses of rubbish, after everything of commercial value has been extracted from it, but the heavy initial costs are a formidable deterrent, tempting authorities to seek cheaper, if less satisfactory, solutions. It should also be admitted that even the best incinerators of this type PUBLIC UTILITIES 963 are known to produce dangerous fumes, so this method of disposal is not problem-free. Other forms of waste such as those produced by many modern industrial plants pose even more serious problems of disposal. Some of them, like the waste from nuclear energy installations and certain chemical works, can present considerable health hazards. Normally, the producers are prevented from emitting these effluents into the air and local rivers by legislative controls, but these are not always adequate and in some cases insufficient to prevent serious accidents with which neighbours to nuclear power stations and large chemical works have had to cope. The maintenance of surveillance in these situations is an important public service, and modern technological equipment such as that used for monitoring the presence of radioactive materials and for protecting personnel against dangerous materials, performs a vital part of this service. ROADS AND POSTAL SERVICES Amongst those secondary services which, although not basic to the existence of civilized social life, go far towards making it more pleasant and satisfactory, the provision of good roads and a postal system are very important. Towns can function without properly surfaced roads and pavements, but the volume of urban traffic makes such improvements desirable at an early stage of town development, and corresponding improvements in roads to neighbouring districts and places further afield provides immediate benefits in terms of communications, so that the efficiency of a postal system is closely related to the condition of the roads. The pressure to improve urban roads came from local residents anxious to protect their property, and resulted in the paving of market places and the surfacing of roads with cobbles or granite setts. The condition of inter-urban roads was not susceptible to the same imperatives for improvement, although it was occasionally subject to military contingencies such as led to the construction of sound main routes between Paris and the frontiers of France, and to the military roads built by General Wade in the 1720s to pacify the Highlands of Scotland. Elsewhere, they were usually left to the inefficient care of local authorities with little incentive and scant resources to undertake substantial road improvement. Industrialization brought both an increase in traffic, which caused more rapid deterioration of inadequate roads, and a new determination to improve the roads, stimulated in part by the need for a more efficient postal service. In Britain, this conjunction of means and needs produced a vigorous programme of road improvement in the second half of the eighteenth century, carried out mainly by Turnpike Trusts which sought increasingly effective professional advice from road builders like John Loudon Me Adam and his family. The many miles of improved ‘macadamized’ road which resulted involved a fairly PART FIVE: TECHNOLOGY AND SOCIETY 964 simple technology discussed in Chapter 8. Stage coaches were quick to take advantage of the improvements and which served, amongst other things, to extend and accelerate the mail services. Stages coaches were first used in place of mounted post-boys for British mail services in 1784, and by the 1830s these vehicles were able to average ten miles an hour over long distances, providing prompt deliveries of mail in most parts of the country. Later improvements became necessary in the roads with the advent of motor vehicles and the pneumatic tyre, because the latter tended to reduce the macadamized surfaces to dust with a consequent alarming increase in the rate of decomposition of the roads. The solutions to this problem, first by tar-spraying and then by the development of highly resilient tarmac and asphalt surfaces, supplemented in some places by concrete, restored the road system and were generally adopted both in the towns, where the old-established cobbled streets tended to disappear, and on the inter-city highways. Postal services have taken advantage of successive improvements in transport technology, readily adopting the railways, often with the provision of special sorting coaches and other equipment, and then accepting the facility for rapid transit over long distances to all parts of the world offered by regular air-line services. Otherwise, however, they do not involve very sophisticated technological equipment, or at least they have not done so until the recent introduction of electronic devices for scanning and sorting letters. The introduction of Rowland Hill’s ‘penny post’ in 1840 brought a great increase in the volume of mail handled by the postal services and the use of adhesive stamps created a need for perforating machines, making it easier to distribute stamps. Franking machines, used to cancel the stamps and to register the time and place of postage were also adopted, and letter boxes were introduced to facilitate the collection of mail, considerable thought being given to the manufacture of a safe receptacle, resulting in the cast-iron pillar box bearing the Royal monogram which, in a succession of forms, has become a traditional feature of the British postal service. More recently, the introduction of air-mail, area-coding, automatic sorting devices, pre-paid stamping machines, and optical character readers (OCR) (see Chapter 15) designed to read key elements in the address and thus accelerate the sorting process, have all helped to cope with an increasing volume of postal communications. Only the last of these involve a high degree of electronic sophistication, and for the most part postal services all over the world remain heavily dependent on human labour. They have, nevertheless, achieved a remarkably efficient standard of handling the mail. TELEGRAPH AND TELEPHONE SERVICES Most countries have assumed responsibility for operating their postal services as some form of public corporation, and many countries have extended this PUBLIC UTILITIES 965 measure of state control to their telegraph and telephone services, although virtually all of these began as private enterprise ventures and in some countries they have remained such. The electric telegraph began in Britain in 1837 as the result of an invention by William Cooke and Charles Wheatstone, who succeeded in transmitting an electric signal along a wire and registering its reception with a deflecting needle on a dial (see p. 714). This system was adopted in the following year in Britain by the Great Western Railway in order to operate its signalling system, for which purpose it became indispensable to the railways in their great mid-century boom because it allowed distant signal boxes to keep in contact with each other. Samuel Morse meanwhile promoted his own system with its characteristic code of dots and dashes in the United States, and the network built up by him under the terms of the Morse Bill in 1843 played a vital part in the westward expansion of American settlement. The establishment of a cable across the English Channel in 1851 put the business communities of Paris and London into instantaneous contact with each other and demonstrated the practicability of submarine cables. Several attempts were made to lay a trans-Atlantic cable before the S.S. Great Eastern was successful in doing so in 1866, and thereafter other cables were quickly prepared to bring the advanced societies of the world into telegraphic contact. The achievement of this objective was signalled in 1872 when the Mayor of Adelaide in South Australia exchanged telegraph greetings with the Lord Mayor of London. The telephone was invented in America in 1876 by A.G.Bell, but it made little progress until two years later when D.E.Hughes invented the electromagnetic microphone which, when added to the telephone, amplified the weak voice currents produced in Bell’s device and thus made it suitable for long-distance communication (see p. 719). As such, the telephone was eagerly adopted by the American business community, and after a slower start it became a universal tool of business and domestic communication in Europe also. The first British telephone company was formed in 1878, and soon afterwards telephone exchanges were established in all the main towns and cities of the country and inter-city lines were constructed. By 1884, there were 11,000 ‘telephone stations’ (i.e. offices and homes with telephones) in Britain, while the United States at the same time had 148,000. As with the development of the telegraph system, British telephony was pioneered by private companies and then taken over by the General Post Office and conducted virtually as a government monopoly. The telegraph network had been taken over in 1868, and by 1912 most of the telephone network had been similarly acquired. By 1958, the GPO was responsible for about 7 million telephones, amounting to about one for every seven inhabitants of Britain, which compared with 67 million telephones in the USA, giving about one for every two-and-a-half inhabitants. Technologically, the telephone service has continued to improve, with automatic exchanges, trunk dialling schemes, a PART FIVE: TECHNOLOGY AND SOCIETY 966 trans-Atlantic telephone cable carrying 35 channels which was opened in 1956, and now the ever-expanding facility for satellite links through telephone stations in synchronous orbits round the Earth which has brought the whole of the planet within the scope of instantaneous voice communication. This has been a technological revolution of tremendous significance, and has provided an outstanding public service. CONCLUSION In several of the public services considered in this chapter, it is important to remember the contribution made in the past 25 years by electronic devices and especially by computers. These ubiquitous innovations of modern technology have made themselves indispensable in many aspects of industrial manufacturing, commerce, transport and communications. It is not surprising, therefore, to find them widely adopted in the public utilities like gas and electricity supply (though less obviously in water undertakings, which still impress mainly by their civil engineering works). These valuable products of modern high technology should not be taken for granted. A sophisticated technology underpins all the basic services which the citizen of modern megalopolis has come to rely upon with remarkable confidence. Consternation is complete when there is a serious breakdown in the system, so that the lights go out, the elevators stop working and the water dries up in the taps. In such circumstances, an awareness of the complexities and interdependence of modern technologies is at least an aid to peace of mind and, at best, a help towards working out the solution to the problem. There are, of course, other problems associated with many of the technologies employed in the public services in addition to the possibility of outright failure. Air and noise pollution, for instance, are insidious facts of modern town life; acid rain derives from our thoughtless consumption of carbon fuels; the urban environment tends to become spiritually and culturally restrictive. But without ignoring these problems, it is salutary to recognize the enormous service of technology to the community in the shape of the public services, and, while trying to eliminate harmful by-products and side-effects, to seek their extension to communities which at present do not enjoy their benefits. It is important, in short, to envisage a goal whereby the sort of public services at present enjoyed by citizens of developed nations are made available to everybody. 967 21 WEAPONS AND ARMOUR CHARLES MESSENGER PREHISTORIC WEAPONS Among the earliest and most widespread of man’s weapons is the spear. Originally it was merely a wooden pole with one end sharpened with a stone or piece of bone, but once palaeolithic man had discovered fire, some 500,000 years ago, charring was also used to harden and sharpen the tip. The next stage was to insert pieces of stone or bone in order to reinforce the point, and then to fit a stone head. From a very early period there were two types of spear, thrusting and throwing. The throwing spear, or javelin, tended to be lighter and in order to increase its range a device called the spear thrower was introduced. This acted as a lever and was a piece of shaped wood, bone or horn with a hook or recess into which the end of the spear fitted. Two of man’s other original weapons are the club and the axe. The club was originally made of hardwood, the head being larger than the handle. Like the tip of the spear, the head was then reinforced with stone. The original axe was made entirely of stone, simply an almond-shaped head sharpened by flaking. In about 3500 BC the wooden haft or handle was introduced, being attached to the stone head by means of bent wood, horn sockets, lashing and gum. Then, during the neolithic or New Stone Age era, 7000–2000 BC, the art of grinding, polishing and drilling of stone was developed, which radically increased the effectiveness of the axe, both as a tool and as a weapon of war. The head was now often fitted to the handle by means of a circular hole drilled through it, known as the ‘eye’. Perhaps surprisingly, the bow was already in existence around 15000 BC. It was first developed by the Mediterranean civilizations, and was taken up in northern Europe during the ninth millennium. From the start, yew, because of its good tensile characteristics, was the preferred wood, although in colder climates, where yew did not grow, elm and occasionally pine were used. Most bows were man-sized, and by the third millennium the composite bow, PART FIVE: TECHNOLOGY AND SOCIETY 968 strengthened with horn and sinews, was in use in some regions. The string was normally made with plaited leather strips. Stone arrowheads were used, and the arrow itself was straightened by passing it through a hole drilled in bone or horn. In order to obtain arrows of standard size—important in terms of accuracy—they were shaved by means of a hollow tube cut as grooves in a split stone. The other basic weapon was the slingshot, a spherically shaped stone which was projected from a leather sling, which the firer whirled above his head in a circular motion in order to impart increased velocity to the stone. THE BRONZE AGE AND CLASSICAL ERA As with much else in the history of technology, the discovery of metal and the coming of the Bronze Age in about 2000 BC had a dramatic impact on weapons. The development of the forced-draught furnace, in particular, enabled the known ores to be smelted and to be fashioned into shapes that could not be achieved, or at least only with much difficulty, by the stone craftsman. Furthermore, damaged metal weapons could be recycled. An added advantage was that much longer cutting and thrusting weapons could be made. Daggers had existed in stone, but, using bronze and copper, the sword could now be made. Both these metals are, however, relatively soft, and in order to make a more durable weapon, which would not bend easily, the metal was strengthened by hammering, then by the addition of lead at the smelting stage (see Chapter 1). Initially, the sword was merely a thrusting weapon, with a strong central rib running down the centre of the blade and smaller side ribs, but gradually a cutting capability was introduced, with double cutting edges. With the discovery of iron, around 1000 BC, weapons became much tougher, but it was a much more difficult metal to work than copper and bronze, and hence for a long time the three coexisted. The growing effectiveness of weapons in their ability to kill and maim caused increasing attention to be paid to personal protection. The original form of armour, consisting of layers of linen wrapped round the body, was used by the Egyptians in the third millennium. Hide was also used and gradually metal strips were introduced; the Sumerians in Mesopotamia had long cloaks reinforced with metal discs during the first half of the third millennium BC. Two basic types of early armour were scaled and lamellar. The former consisted of a short tunic on which were sewn overlapping bronze scales, while lamellar armour had pliable metal plates, or lames, which were laced together in slightly overlapping horizontal rows. Later, in about the 5th century BC, chain mail was developed by interlinking metal rings, or sometimes wire. Like body armour, helmets were originally made of cloth, but this gave way to leather, metal, or a mixture of the two. Apart from the basic conical style, helmets with cheek pieces to protect the face from sword cuts WEAPONS AND ARMOUR 969 became popular. Often they were elaborately decorated, including horns and crests, not merely from male vanity but more to make the wearer look imposing and formidable in the eyes of his enemies. The third major item of personal protection was the shield, which was certainly in common use by the beginning of the second millennium BC. Shields existed in several different shapes—round, rectangular and oval—and were made of leather, leather-covered wood and wickerwork. They also often had overlaid thin strips of metal which were used both decoratively and to provide additional protection. Before 1000 BC the main centre for both military and political development was bound by the three major rivers of the Middle East, the Nile, Euphrates and Tigris, with the two dominant countries being Mesopotamia and Egypt. From about 3500 BC the dominant weapon in Mesopotamia was the chariot, which gave warfare much greater momentum and punch than hitherto. Originally it was drawn by asses, until the horse arrived from the steppes of Mongolia around 2000 BC. Chariots were used to make frontal charges on the enemy in order to create panic, their crews being equipped with both javelins, to engage at medium range, and spears for hand-to-hand fighting. By 1500 BC, with the development of the spoked wheel, means were found to make the chariot lighter and hence more mobile, thus increasing its effectiveness as a weapon of shock action. Surprisingly, the Egyptians did not use the chariot until about 1600 BC, but it quickly became the basis of their military might. Armed also with the double convex shaped composite light bow, with a range of 275–365m (1200–1600ft), which they used both mounted in their chariots and on foot, they became a formidable force. Indeed, it was the arrow projected by the light composite bow, with its reed shaft and bronze head, which brought about the need to consider personal protection. It was not until the rise of the Assyrians at the end of the second millennium BC that horse cavalry began to appear, and then in only a secondary role on the battlefield, being used to harry the enemy’s flanks, while the chariot remained the decisive weapon. Early cavalry were armed with both bows and spears, but their horses had merely a bridle, with no stirrups. So formidable was the Assyrian army that opposing forces would not take to the field against it if they could avoid it. Instead they relied on the protection of the fortified city, a concept which had been in existence since the third millennium. An example is the fortress of Megiddo, which was built at the beginning of the nineteenth century BC. The base of its main wall was 2.13m (7ft) and it had 5.5m (18ft) salients and recesses, with a crenellated parapet on top. To counter these strong defences the Assyrians introduced battering rams designed to break down the main gates to the city. They were mounted in wooden towers, which were roofed and protected by metal plates, and were borne on six wheels. Under the roof was a platform used by archers to shoot at the defenders on the walls. Tunnelling and scaling ladders were also used. PART FIVE: TECHNOLOGY AND SOCIETY 970 By 500 BC, the Greeks had become the major military power and they made two significant contributions to the history of warfare. The first was the phalanx, a close order formation made up of hoplites, infantry equipped with 2.44m (8ft) spears and swords and dressed in horsehair-plumed helmets, breastplates and calf and shin plates known as greaves, with a 0.91m (3ft) diameter round shield held on the left arm. This tightly packed ‘mobile fortress’ was frequently more than a match for looser and less well disciplined bodies of enemy. The other development engineered by the Greeks was the invention of torsion artillery, in the shape of the catapult. It was the Alexandrian mathematicians who developed the theory of the catapult, showing how there was a direct correlation between the proportions of the various parts and the diameter of the ‘straining hole’ through which the skeins which controlled the tension passed, and the Greeks who put it into practice. They had two types of catapult (or ballista, as the Romans were to call it). The katapeltes were used to project arrows, javelins and smaller stones—a 3.63kg (8lb) stone could be projected accurately to a range of 228m (750ft)—while the larger petrobolos could hurl stones of up to 25kg (55lb) in weight. The skeins themselves were made of twisted human hair and sinew. A further refinement was the use of fire arrows, either with their heads wrapped in inflammable material and ignited just before firing, or made red hot by heating in coal fires. Unlike the Greeks, the Romans were not innovators but very practical engineers, who applied the ideas of their predecessors. Perhaps their most outstanding feats of engineering were the numerous aqueducts which are still to be seen today. The Romans have been called ‘the greatest entrenching army in history’ and it was a constant principle that when legions halted after a day’s march they constructed a fortified camp, usually square in shape, with ramparts, palisades and ditches. Apart from the comfort afforded, it also meant that they always had a secure base from which to operate. Roman camps, especially those near rivers, are the foundation of many of today’s European towns and cities. As with the Greeks, the main element was the regular infantry of the legions, whose members were armed with a short stabbing sword, javelins and spears. The main shield used as the scutum, large and semi- cylindrical rectangular in shape, which when rested on the ground would come up to a man’s chest. With this shield they went one stage further than the mobile phalanx of the Greek hoplite by developing the testudo or tortoise, especially useful in sieges. While the outside ranks protected the front and flanks with their shields, those on the inside put theirs over their heads in order to provide protection from arrows and missiles fired from above. Cavalry still played a secondary role and, indeed, the Romans tended to rely on mercenaries or ‘auxiliaries’ to provide it as well as their archers and slingers. One new weapon of war introduced was the elephant. The Greeks had used it as heavy cavalry, but it was the Carthaginians who brought it to the fore at the WEAPONS AND ARMOUR 971 end of the third century BC, and their celebrated general Hannibal took elephants on his march across the Alps which led to defeat of the Romans at Cannae in 216 BC. The Romans finally gained their revenge at Zama in 202 BC by using trumpets to panic and stampede the beasts. THE DARK AGES By 400 AD the Roman Empire was beginning to disintegrate in the face of Vandals, Goths and then Huns from the east. These races relied almost entirely on the horse, and they brought with them the stirrup, which was responsible more than anything else for the gradual elevation of cavalry to the decisive arm on the battlefield. Stirrups gave the rider the necessary stability to withstand the shock of the charge and meant that cavalry could now be committed against the main force of the enemy rather than merely harrying his flanks and being used in the pursuit. This, combined with brilliant horsemanship and the hardiness of their mounts, which could travel up to 160km (100 miles) a day, as well as the use of mounted archers en masse, made the Huns especially a devastating military power. One relic of the Roman Empire in south-eastern Europe became the Byzantine Empire, which successfully withstood the ravages of Huns, Arabs, Turks and Magyars for five centuries before succumbing to the Turks at the Battle of Manzikert in AD 1071. The Byzantines built their armies around the cavalryman, having taken the Hun model to heart. He was dressed in a long chain-mail shirt down to his thighs with steel helmet, gauntlets and shoes and was armed with a heavy broadsword, dagger, short bow and lance. His horse had a saddle and iron stirrups and was sometimes protected by a poitrel or breastplate. There were two types of Byzantine infantry, light, which mainly consisted of archers, and heavy, armed with lance, sword and axe. In battle they held their ground while the cavalry achieved victory through repeated charges at the enemy. During this period the first chemical weapon made its appearance. This was Greek Fire, which was certainly used by the Byzantine defenders of Constantinople during some of its numerous sieges in the seventh and eighth centuries. It was, in essence, liquid fire and a forerunner of today’s napalm. No precise recipe for making it exists, but the main ingredients were sulphur, pitch, nitre and petroleum, which were boiled together. It was effective on both land and sea and appears to have been used in siphons or as a grenade made of glass or pottery. During sieges it was often delivered by means of ballistae. The equivalent to the Byzantine Empire in the west was that of the Franks. Initially they were reliant on infantry, which was only lightly armoured and armed with axes and barbed javelins, used as both throwing and thrusting weapons. The axe, which was rather like the Red Indian tomahawk, was an . which the end of the spear fitted. Two of man’s other original weapons are the club and the axe. The club was originally made of hardwood, the head being larger than the handle. Like the tip of the. of enemy. The other development engineered by the Greeks was the invention of torsion artillery, in the shape of the catapult. It was the Alexandrian mathematicians who developed the theory of. motion in order to impart increased velocity to the stone. THE BRONZE AGE AND CLASSICAL ERA As with much else in the history of technology, the discovery of metal and the coming of the Bronze Age in