An Encyclopedia of the History of Technology part 97 pdf

PART FIVE: TECHNOLOGY AND SOCIETY 942 economical, easy to use and needing a minimum of attention, it was made of cast iron and enclosed in an enamelled insulated jacket: Dalen used kieselguhr, a diatomaceous earth, as insulating material. The heat was conducted to the various parts at precisely the correct temperature for the types of cooking needed: boiling, baking, grilling etc. The temperature of the hob plates was maintained by the fitting of insulated hinged covers which were retained in place when the plates were not in use. The Aga was introduced in Britain in 1929. It is still in use today but the modern version is thermostatically controlled and can function on solid fuel, gas or oil. Cooking by gas In the early nineteenth century, as the supply of gas was extended (see Chapter 3), experiments took place to try to use the fuel for cooking, but the problems of making it financially viable were formidable. The cost of gas was much greater than coal; there were no meters, so there was difficulty in measuring consumption; more important still, the public were prejudiced against the use of gas, believing it to be dangerously explosive and the fumes and impurities in the gas to be harmful to any food cooked by it. Despite these problems inventors continued to try to make satisfactory appliances. One of the early workable devices was a griller of 1824, made at the Aetna Ironworks near Liverpool. It was a kind of gridiron made from a gun-barrel, with holes pierced in it, then twisted round to a circular shape. It could be used horizontally with pans placed on top or vertically so that a joint could be roasted in front. Commercial, box-shaped cookers were marketed from the 1830s and in 1847, A.A.Croll read a paper to the Royal Society of Arts in London on the ‘Domestic Uses of Gas’. In this he referred to Alexis Soyer, the famous French chef, who took the lead in promoting cooking by gas because he believed it to be clean, efficient and economical in comparison with coal; he had introduced it into the kitchens of the Reform Club in London in 1841. By 1855 there were many designs of appliance on the market and gas cooking had been clearly demonstrated to be a practical proposition, but it was only used by a small minority of the population. The chief reasons for this were the still entrenched fear of using this type of fuel and its high cost. The incorporation of Bunsen-type atmospheric burners helped to popularize the cookers, but because gas was still more expensive than coal, coupled with the fact that most people already possessed a coal range, acted as a great deterrent. Two important incentives were then offered by the gas companies which tipped the scales in favour of gas cooking. The first was the introduction in the 1870s of facilities for hiring cookers instead of insisting on purchase. The second, which came in the 1890s, was the installation of prepayment slot THE DOMESTIC INTERIOR 943 machines, which brought gas within the financial reach of everyone. By 1911 the Gas Light and Coke Company were taking 230 million pennies annually from their machines, an amount which weighed nearly 2000 tonnes. From the 1890s gas largely took over from coal as a cooking fuel, but the design of the cooker continued to be cumbersome and difficult to clean. It was made of the same materials as the kitchen range—cast iron, which needed black-leading, with taps and fittings of brass and steel, which were hard to keep shiny (see Figure 19.7 for an example of this period). It was only with the dearth of servant labour which occurred after the First World War and the consequent demand of housewives for a more attractive and labour-saving appliance, which they then had to clean themselves, that the manufacturers responded. Cookers appeared clad in cream enamelled iron sheeting, replaced in the 1930s by coloured vitreous enamel. The design was streamlined and ovens were lined with easy-to-clean materials. Technical advances followed also, the most important of which was the introduction in 1923 of oven thermostatic control—Regulo—developed by Radiation Ltd. Innovations after the Second World War included the standardization by manufacturers of their thermostat settings, the introduction of the high-level Figure 19.7: Parkinson cooker, c. 1890. Made of cast iron with silicate packing for insulation. Water heater at left side. Plate warming hood over hotplate. The Gas Council. PART FIVE: TECHNOLOGY AND SOCIETY 944 grill, automatic ignition to burners, thermostatic hot-plate burners and lift-off oven doors. The design was further streamlined and the cooker lost its legs, the space at the bottom being utilized for a storage drawer. The Sola Grill appeared in the 1960s. Since 1965 has come conversion to natural gas, automatic oven timing, self-clean oven linings, electric spark ignition for burners, graduated simmer control and the flame-failure safety device. Cooking by electricity The possibilities of cooking by electricity were being explored as early as the 1890s. In 1891 an electric cooker was demonstrated at the Electrical Fair at Crystal Palace and two years later a model electric kitchen was on display at the Chicago World’s Fair. Meanwhile, in Britain, Crompton, in collaboration with Dowsing and Fox (see p. 916–17), was designing and manufacturing a range of electrical appliances. In 1900 the Crompton Company catalogue was advertising ovens, hot-plates, saucepans, frying pans, kettles, coffee urns and hot cupboards. Most of the early cookers, like the Crompton designs, consisted of a number of separate appliances. The oven was like a safe, made of metal sheeting on a metal frames. It was heated by elements at top and bottom, controlled by brass switches; the elements consisted of cylindrical ceramic formers coiled with wire. The oven had no hot-plate but there were a number of ancillary appliances—griller, kettle, frying pan and hot-plate—which were all wired separately and plugged into a panel of wall switches; these appliances were put on top of the oven or on the floor beside it. Like gas cookers, electric cookers were for many reasons slow to attract custom. By 1900 they were a practical proposition but they were, like their gas counterparts, black, ugly and difficult to clean. Also, people distrusted them. The heat was not visible and it was easy to burn oneself. The elements were as yet unreliable; they easily burned out, they took a long time to heat up and so were expensive to use. Most people already had a gas cooker and/or solid fuel kitchener and, lastly, only a minority of homes were yet wired for electric current. Various attempts were made in the 1920s to convert customers to ‘cooking electric’. Electric lighting companies offered to hire cookers. Smaller cookers of more attractive design were produced. C.R.Belling brought out his ‘Modernette’ made of light steel which had two boiling burners on top, a grill, plate warmer and oven, all in one conveniently designed cooker. But, like all electric cookers of the time, the burners were of open type and if the contents of a saucepan boiled over, the spillage ran directly down on to the heating element, usually causing a short circuit. It was not until the 1930s that electricity began seriously to compete with gas for cooking, Figure 19.8 shows an example of the first generation of THE DOMESTIC INTERIOR 945 successful electric cookers. By 1939 over a million households were using electricity compared to nine and a half million opting for gas. But, by this time also, most households were wired for electricity and great improvements had been made in the design and technical performance of the cookers. Appearance and materials had kept pace with gas appliances. Functionally the fast-heating tubular-sheathed radiant rings had replaced the earlier burners and later solid hot-plates, which had been slow to heat, and ovens were thermostatically controlled. Since 1950 electric cookers have marched in step with gas cookers in all modern advances. Importantly, what had always been the great drawback of electric cooking—the excessive time taken for elements to heat up and consequent high expense of using the appliance—has been overcome. Boiling rings heat quickly and split rings lead to economy. There is a wide range of heat control. With the 1970s came the ceramic hob and the cool-top hob, both products of modern technology. In the 1980s the cost of electric current is now only marginally greater than gas and new cookers are so fast, clean and efficient in conservation of energy that running costs are not dissimilar. Also electric cookers tend to be cheaper to purchase than their gas counterparts. Figure 19.8: Creda electric cooker, 1933. First model to have thermostatic control of oven. Hot plate has two elements, one of the new spiral tube type, the other a metal plate with coiled wire element beneath to heat grill. PART FIVE: TECHNOLOGY AND SOCIETY 946 These factors have dramatically altered the nation’s preferences and over 40 per cent of the population use electric cookers. The pressure cooker Denis Papin, the French physicist, invented the first pressure cooker, which he called ‘A New Digester or Engine for sofning Bones’, in 1679 and he demonstrated it two years later at the Royal Society. His vessel was designed with a tight-fitting lid and had a safety valve to guard against excessive rise of pressure. The idea of a pressure cooker is that a vessel is designed to seal in and control the steam which normally escapes when cooking is done in a saucepan. As the steam is retained, the pressure rises and so does the temperature at which the water boils. The pressure forces the super-heated steam through the food, so greatly reducing the cooking time needed. After Papin the idea languished, but it was revived during the nineteenth century when a cast-iron version was marketed: it was called a digester. Cast aluminium was used in the 1930s and pressure cookers, as they were then termed, were fitted with pressure gauges on top. The modern cooker is made of aluminium or stainless steel and has a non-stick finish. Pressure cookers have been in less demand since 1960 owing to the introduction of such alternatives as readily available convenience foods, the auto-timer fitted to cookers, the slow cooker and the microwave oven. Microwave ovens Microwave cooking makes use of short radio waves (as short as 12cm (4.75 in)). Such waves were first generated by Britain and the USA for the operation of radar during the Second World War. Americans then adapted the research for cooking and produced a microwave cooker; the method was introduced to Britain in 1959. Whatever the means of cooking the effect of the heat is to raise the temperature of the food, by increasing the agitation of its constituent molecules. In traditional cooking methods by solid fuel, gas or electricity, the surface of the food is heated from an exterior source and it is only cooked to the centre by such heat after a considerable period of time has passed. In microwave cooking the radio waves penetrate very quickly to the centre of the food and raise its temperature. Microwave cooking will not, therefore, ‘brown’ food; if this is desired it must be done afterwards by conventional heat. The interior of a microwave oven has polished reflecting surfaces which concentrate the microwaves on the food. Also, a rotating fan is attached to the THE DOMESTIC INTERIOR 947 roof of the oven in order to spread the heat evenly. As is well known, microwave cooking and de-frosting is extremely fast. As it is only the food which is heated and not the oven, such cooking is extremely clean as well as inexpensive. The output power of most microwave ovens is thyristor-controlled and microprocessor control is gradually being introduced. PLASTICS IN THE HOME No material has ever changed the appearance of the home as much as plastics have done and it is not only appearance but their resistance to wear and their easy-care characteristics which have altered everyone’s way of domestic life. The word, which derives from the Greek plastikos, meaning ‘that which may be moulded, describes their quality of being easily shaped to any required form. The development of plastics took place rapidly in the years since 1920 (see Chapter 3). In the modern home a very wide range of plastics is in use for a great variety of purposes. Three types which particularly serve domestic needs are polyvinylchloride (PVC), polyethylene and polystyrene and each of these may be found in different forms which meet different needs. For example, PVC (often called simply vinyl) may be manufactured to be rigid or flexible, thin or thick, transparent or opaque. The rigid type is suited to the making of structural parts such as piping and guttering; it is also used for making gramophone discs. Vinyl floor tiles or soles for footwear are manufactured from a more flexible version. A softer type is used for a wide range of goods from furnishing fabrics and garments to wallpaper and hosepipes. Transparent PVC provides the wrapping film used for a multitude of purposes in the kitchen. There are two chief types of polyethylene—more commonly known as polythene. An early type was produced as long ago as the 1930s, when it was manufactured into sheets of fairly heavy wrapping material. High density polythene was developed in the 1950s. This is heavier and more rigid and has proved most suitable for making a range of useful containers such as buckets, large bowls and dustbins. Polystyrene appears in three chief forms in the home. There is the toughened type which lines refrigerators, the clear but strong and rigid type made into moulded containers for eggs, butter, salads etc. and expanded polystyrene, which is a lightweight foam ideal for a broad range of goods from moulded packaging to ceiling tiles. A more recent development is the use of glass fibre as a reinforcement for plastic. Polyester is ideal for this purpose and this combination of materials has made the use of plastics possible for heavy, structural parts of a house as well as for articles such as water tanks. Apart from all these widely used plastics there are others of particular assistance in the kitchen. The development of non-stick cookware has been PART FIVE: TECHNOLOGY AND SOCIETY 948 made possible by the use of polytetrafluorethylene, generally abbreviated to PTFE, which is inert to a wide range of chemicals and is also resistant to sunlight and to moisture. Polypropylene is a rigid thermoplastic which is highly resistant to liquids and solvents, so is used extensively for kitchenware of all kinds as well as garden equipment such as wheelbarrows. Elsewhere in the house melamine resins are made into unbreakable tableware and phenolic resins into electrical fittings. Carpets are backed with polyurethane foam. Lastly there is the extensive range of synthetic textiles manufactured into garments and furnishings fabrics, dating from the first production of nylon by Du Pont of America in 1938, after eleven years of research costing $27 million, to the later numerous varieties of polyester and acrylic fibres marketed under the plethora of different trade names adopted by their countries of manufacture. FURTHER READING Adamson, G. Machines at home (Lutterworth Press, Cambridge, 1969) Conran, T. and C. Kitchens past and present (Hygena Ltd., 1976) Haan, D. de Antique household gadgets and appliances c. 1860–1930 (Blandford Press, London, 1977) Harrison, M. The kitchen in history (Osprey Publishing, London, 1972) Hole, C. English home life 1500–1800 (Batsford, London, 1949) Joy, E. The Country Life book of English furniture (Country Life, London, 1964) Lindsay, J.S. Iron and brass implements of the English home (Tiranti, London, 1964) McRobert, R. Ironing today and yesterday (Forbes Publications, London, 1970) Megson, B. English homes and housekeeping 1700–1960 (Routledge & Kegan Paul, London, 1973) Singer, C. et al. A history of technology ( 7 vols .) (Clarendon Press, Oxford, 1958–78) Wright, L. Clean and decent (Routledge & Kegan Paul, London, 1960) —— Home fires burning (Routledge & Kegan Paul, London, 1964) Yarwood, D. The English home (Batsford, London, 1979) —— The British kitchen (Batsford, London, 1981) —— 500 years of technology in the home (Batsford, London, 1983) 949 20 PUBLIC UTILITIES R.A.BUCHANAN INTRODUCTION The complexity of modern life and, in particular, the organization of large towns and cities on which it is based, can only be sustained by an intricate network of public services. When towns were generally small, such services were simple because the population could depend upon local wells and rivers for their water supply, and food and raw materials were available from the adjacent countryside. But the magnificent Roman system of roads and aqueducts should remind us that even ancient cities required basic services in order to function efficiently. The skills which had created these engineering achievements were virtually forgotten in western Europe for many centuries, during which most towns were small and their services rudimentary. During these centuries, the existence of a river or a fast flowing stream was usually all that was necessary in the way of water supply, providing for drinking, drainage, sewage and garbage disposal, transport, power for industry, and fire- prevention measures. As long as towns remained small and could retain an intimate association with the surrounding countryside, such multiple use of natural water-courses could sustain them indefinitely. With the onset of rapid industrialization in western Europe at the end of the eighteenth century, however, towns grew prodigiously as centres of trade and industrial production, and with this development the need to provide adequate services became critical. Failure to make adequate provision almost caused a breakdown of British town-life in the 1830s and 1840s, when the ravages of cholera and other diseases induced by overcrowding in insanitary conditions were most severe. But from the middle of the nineteenth century a determined effort was made to improve the conditions of life in the towns of Britain. The appalling squalor reported in dozens of official statements by doctors and administrators, and described so vividly by Friedrich Engels in his account of Manchester in 1844, became a thing of the past, replaced by towns which had a good supply of fresh PART FIVE: TECHNOLOGY AND SOCIETY 950 water, an efficient means of disposing of organic waste and garbage, and all the other services of paving, lighting, transport, shopping and trading facilities which have come to be taken for granted as the normal features of life in ‘megalopolis’— the huge urban conglomerations which have become the dominant pattern of existence for most people in the developed nations of the twentieth century. All the public services which sustain megalopolis have been created by the co-operation of many individual technologies developed over a number of years. These technologies are the subjects of other parts of this volume but the present chapter is concerned with the development of those public services which have made life in large towns and cities possible. The services considered fall into two categories: (1) The primary services of water supply (sources, treatment, distribution, drainage and sewage disposal), power supply (gas, electricity, hydraulics and pneumatics) and waste disposal. (2) The secondary road, postal, telephone and telegraph services. WATER SUPPLY Water supply is the most basic of the public service industries. No town can survive for long without a supply of water for drinking, washing and various industrial processes, so that if a convenient source such as a river or a well does not exist it has to be provided, or if natural sources are inadequate they have to be supplemented. Substantial resources of materials, man-power and technological skill have thus been required wherever town life has flourished on a large scale in order to ensure that the need of an urbanized population for a constant supply of water can be fulfilled. The ancient civilizations of Egypt and Mesopotamia established intricate irrigation works, bringing water to their fields and cities. Pergamon in Asia Minor and the Greek city-states constructed elaborate systems of culverts and aqueducts to bring water to their citizens. And the Romans made a fine art of the technology of bringing water long distances in masonry aqueducts to serve the large cities of their Empire, and especially Rome itself. The remains of many of these aqueducts survive as eloquent testaments both to the engineering skill of the men who designed and built them, and to the quality of urban life which they made possible. Sources All water becomes available in the course of the hydrological cycle, whereby water is evaporated from the oceans and precipitated on the land surface, PUBLIC UTILITIES 951 whence it can be obtained from rivers and lakes, or recovered from springs and wells if it sinks into the ground to replenish the underground accumulation of water or aquifer. In certain geological conditions where the aquifer is under pressure in a basin of water-bearing strata, the water will rise spontaneously up a shaft bored into it—an artesian well. Normally some form of pumping or water-raising apparatus is required. By far the simplest form of urban water- supply is thus a river, and for many large towns, including London, this has remained the largest source down to the present time. Although direct extraction from the turbid tidal reaches of the River Thames was abandoned in the mid-nineteenth century, the Metropolis Water Act of 1852 prohibiting the extraction of drinking water below Teddington Weir, the bulk of London’s water supply still comes from the Thames and the Lea, through the elaborate catchment reservoirs and treatment plant between Staines and Surbiton, and in the Lea Valley. London, of course, has had a long history of water supply difficulties, but most of the successful schemes such as the water-wheel- powered pumps built into an arch of the Old London Bridge by the Dutch engineer Peter Morice in 1582, and the more ambitious scheme of Sir Hugh Myddelton’s New River project in 1619, which brought water into the city through an artificial channel from the Hertfordshire countryside, relied upon river catchment in one form or other. Subsequently all rivers with a reliable flow of water in western Europe and many in other parts of the world have been liable to have a proportion of their volume extracted for public supply either immediately or at a considerable distance from the point of extraction. Of large rivers flowing through industrialized countries like the Severn in England and the Rhine in West Germany and the Netherlands it has been recognized that any cup-full of water drawn from them might make several cycles through supply and waste disposal in the course of flowing from their source to the sea. The device of impounding rivers to provide reservoirs for water supply, river control and irrigation, is very ancient. One of the oldest civil engineering structures in the world is a dam built for such purposes at Sadd el-Kafara in Egypt, 32km (20 miles) south of Cairo, dating from the third millenium BC, and many similar archaeological relics of dams survive. Most early dams were gravity dams—being embankments or masonry walls built straight across a valley and resisting the load of the water by their weight. More sophisticated forms are the buttress dam in which a fairly slim masonry wall is supported by a series of buttresses on its down-stream face, and the arch dam in which a thin curved wall depends upon arch action for its strength as the main load is thrown into the adjoining cliffs, making it possible to build a lighter structure than in other forms. The arch dam has proved particularly suitable for large modern dams in mountainous terrain, where concrete has been used as the main structural material. The spectacular Hoover Dam across the Colorado River in America is an outstanding example of this type, demonstrating the . quickly and split rings lead to economy. There is a wide range of heat control. With the 1970 s came the ceramic hob and the cool-top hob, both products of modern technology. In the 1980s the cost of. made a fine art of the technology of bringing water long distances in masonry aqueducts to serve the large cities of their Empire, and especially Rome itself. The remains of many of these aqueducts. account of Manchester in 1844, became a thing of the past, replaced by towns which had a good supply of fresh PART FIVE: TECHNOLOGY AND SOCIETY 950 water, an efficient means of disposing of organic