An Encyclopedia of the History of Technology part 79 potx

PART FIVE: TECHNOLOGY AND SOCIETY 762 the collection and interpretation of economic data, such as the plant and animal remains which sophisticated retrieval techniques have increasingly yielded from excavations. What is perhaps most surprisingly illustrated from the prehistoric evidence, is how quickly the basic tool kit was established, and how sophisticated it was in terms of the tasks for which it was designed. Huge steps have been taken in the development of machinery in the intervening ten or so millennia, but machinery merely allows greater acreages and bigger yields to be handled more easily and more swiftly: the basic processes of cultivation and harvest, in both crop and animal husbandry, have really changed very little. Until very recently the search for agricultural origins was pursued by Europeans who brought their own particular regional bias to the interpretation of the data before them, and indeed this bias influenced the type of data they sought in the first place. Since the origins of European religion are to be found in the Middle East, it is perhaps not surprising that the origins of civilization were sought here also. Civilization in this context was seen in terms of a socially stratified society, believing in the concept of a divine being, and with the ability to write of this mythology for the benefit of existing and future generations. To the early nineteenth- century antiquarian only a sedentary population, living in an urban setting, was capable of the sophisticated thought needed for such ideas, and only an efficient agricultural system was capable of producing sufficient food to allow the priests, metal workers or merchants to devote their time and energies to their trades and professions. Within this setting those who produced the food would be totally involved with the process, and would have no input into the other activities. These beliefs were held well into this century, and it is only since the Second World War that we have achieved a better understanding of the strategies of the various subsistence economies that still exist on this planet. In doing so we have perhaps been able to guess more accurately the economies of prehistoric societies, and the shifts in those societies that resulted in the profound change from hunter gatherer to farmer. Because of the background to this study, the bulk of archaeological research has been directed to the Middle East, the Mediterranean littoral and to Europe. It is therefore not surprising that most of the information available to us is from this region, and that the oldest dates that can be applied to artefacts and technologies should also reflect this bias; but there are still vast areas of the world that have yet to be explored above the ground, and which may contain remains below that could alter our view of the origins and spread of agricultural technology, or which might push its date even further back than can at present be contemplated. HUNTER GATHERER TO FARMER The studies of hunter gatherer societies that have been conducted over the past thirty years indicate that these groups spend embarrassingly little time on food AGRICULTURE 763 procurement, that they utilize only a small percentage of the plant and animal resources available to them, and that therefore the population density within the territories that they occupy is well below the density that the area could sustain. There are not many hunter gatherer groups available to study, and those that do exist inhabit marginal areas which have been ignored or discarded by those societies whose economies are based on a settled agriculture. If these marginal areas can be so effectively utilized today, it is not unreasonable to suppose that the prehistoric hunter gatherer, living in more favourable climates, enjoyed a comparable standard of living with perhaps even less energy expenditure. The relative importance of plants and animals within the diet of these prehistoric groups is difficult to determine. Studies of modern groups show a dominance either of animals, as in the Ache tribe of East Paraguay, or of plant material, such as characterizes the diet of the Kung of the Kalahari in southern Africa. The latter have been frequently held as the example to prove that our ancestors were predominantly vegetarian; in fact this dietary balance is much more likely to be an adaptation to an environment from which animals have been eliminated by over-exploitation in comparatively recent times. In attempting to understand the transition to an agriculturally based economy, it has been necessary to study the subsistence strategies at either side of it, and it is perhaps ironic that in this process we should have found a better awareness and respect for the abilities of those hunter gatherer groups who are still so successfully exploiting their harsh environments. Although the projection of ethnographic studies back in time must be viewed with caution, it is worth noting how superbly efficient are the modern groups within their own environment. Western society tends to view their technology, culture and subsistence as crude, and yet few of its own members would be able to survive in these environments. To achieve this success it is essential that their understanding of plants and animals should have attained a high level. It is not unnatural that this should have been so, since these peoples are as much affected by as affecting the environment in which they live. Before the invention of radio carbon dating it was very difficult to establish relative chronologies and particularly difficult to make comparisons between artefacts found on different continents. However, as soon as this new technology was applied to the organic material derived from different sites throughout the world, it became quite apparent that the long-held belief of the origins of agriculture in the Middle East, and its subsequent spread from there to all parts of the world, was difficult to sustain. There now exists ample evidence to support the concept of the independent origins of both animal and plant domestication in many unconnected sites in the world, and it is likely that an economy based on plant husbandry was established well before one which incorporated a full animal husbandry. PART FIVE: TECHNOLOGY AND SOCIETY 764 Cultivation In terms of the numbers of people who base their diet on a particular commodity, the three major plant species for human consumption are wheat, rice and maize. The bulk of the evidence for the first has again been found in the Middle East, in that area generally referred to as the Fertile Crescent, which extends from the Euphrates and Tigris river basins, through south- eastern Turkey, and also along the eastern Mediterranean. Arguments have been put forward for a wider area of origin extending along the north coast of Africa, and also into eastern Europe. Whatever the geographic source, the timing of the shift from the collection of wild species to the cultivation of seed and the subsequent selection which led to domestication seems to lie about 10,000 years ago. The ancestors of modern bread wheat are varied but can be traced back to primitive einkorn, and perhaps more importantly to emmer wheat. The latter, a plant with a great resistance to fungal attack and a very high protein content, is to be found in the archaeological context in most areas of early settlement agriculture, ranging from the Fertile Crescent, down the Nile valley, up into Anatolia and the Balkans and into continental and northern Europe. Grains of domesticated wheat, dating from between 7500 and 6500 BC, have been discovered at various sites in the Fertile Crescent. Tell Mureybit in Syria has yielded samples from the earlier date, those discovered at Jarmo in Iraq to 6750 BC. Hacilar in Turkey has realized a date of 7000 BC, and there is evidence for the spread of domestic forms into Europe by the fourth millennium, and into the Nile valley a thousand years earlier. It appears in the Indus valley by the third millennium, and the earliest evidence from China dates to the middle of that millennium. Early domesticated barley has also been found at Mureybit, and in Jericho by about 7000 BC, Greece by 6200 BC, and Anatolia by about 6000 BC. The presence of barley is of particular significance, because it will tolerate poorer soils than wheat, but in the region in question the poorer soils could only be effectively used if irrigation techniques were also employed. Although the presence of barley does not necessarily indicate the use of irrigation, evidence for this technology can frequently be demonstrated on these sites. The wild ancestors of maize are difficult to identify, and there are a number of contenders for the title. Some Mexican material retrieved in the 1960s can be dated to 5000 BC, and are definitely domestic. Their cultivation moved slowly southwards, reaching Central America by at least the middle of the third millennium, and possibly considerably earlier. The early history of rice is less clear. It has been retrieved from a site in Thailand at levels dated to 3500 BC, and in China in levels dating to between 2750 and 3280 BC. It has also been dated to 2500 BC in India. AGRICULTURE 765 Animal husbandry It is perhaps not surprising that the successful hunter groups, with their detailed knowledge of animal behaviour, should eventually begin to manipulate both this behaviour and their own, in order to exploit animal resources more efficiently. Past assessment of this transition has always assumed that this change in strategy was merely to facilitate the procurement of meat. However it has recently been suggested that it was the products realized from live animals which were the true incentive for such a dramatic alteration in life-style. Milk and wool are the most obvious products and in addition the occasional letting of blood is attested from ethnographic evidence. However the most significant of these secondary products to subsequent development is the power of the animal itself. Probably in the beginning only realized by their use as pack animals, the idea was later conceived to harness the animals to haul loads. The earliest evidence suggests that this draught potential was first utilized for the transport of goods and people, but then later the idea was transferred to mechanical tasks such as ploughing. Later still, with the invention of gearing, animal power could be exploited for industrial purposes (see Chapter 4). The concept of these secondary products provides some explanation for the very limited number of animal species that have become established as domestic animals, since there would be a very much tighter specification of requirements than would have been the case if the procurement of meat had been the sole purpose of the exercise. If it is accepted that it was these secondary products that were the stimulus to animal domestication, then there is the need to review also the stages of change from hunter gatherer to farmer. The most logical progression would appear to be for a hunter of wild game to begin to control the movements of the wild herd to his own advantage, and within a limited territory of his choice. This type of economy is to be found today in Finland, where the Lapps control and exploit herds of reindeer. The logical progression from this is to the pastoralist with a fully domesticated herd, and then to a settlement economy making use of the milk and wool obtained from this herd. This progression also allows for the plant gathering element of the economy to move to a settled regime, planting and harvesting crops, and exploiting the animals for both their strength and their manure. However, modern pastoralist economies are very dependent on settlement agriculture for supplies of industrial goods and feeding stuffs for their animals, and also as a market for their surplus products. Indeed in many societies the pastoralists themselves are landholders and therefore control most of the steps within the whole economy. It seems much more likely that a system of settlement agriculture gave rise to a nomadic tier within its economy, than that the process should have occurred in the other direction. PART FIVE: TECHNOLOGY AND SOCIETY 766 Fishing The cultivation and harvest of domestic plants implies the existence of settled communities if only because the storage of produce has little point unless it is easily accessible later in the year. Early interpretation of archaeological data assumed that the opposite was also true, and that permanent settlement was only possible with an established agriculture. While this might be the norm, there is sufficient ethnographic evidence to show that other means of subsistence are capable of supplying adequate food for year-round occupation of a site. For example, the Kwakiutl and Haida tribes inhabiting Nootka Sound in North America were but two of the tribes who exploited the salmon runs to such effect that they were able to establish large permanent settlements with a very rich culture. The fish were consumed fresh or gutted and then either sundried or smoked for storage. In addition to the salmon, an oil-rich fish known as candle fish was also exploited. They were pressed to extract the oil from the flesh, which was then eaten. Oil extraction, smoking and salting were the most usual methods for the storage of fish, whatever their size, before the invention of refrigeration. Smoking seems to have been practised from the very earliest of times, and strong evidence for its use is to be found at the site of Lapenski Vir, which was situated on the Iron Gates gorge on the River Danube. This site would appear to have been seasonally occupied about 4500 BC, and existed because of the quantity of catfish which could be caught during the summer months. The site has realized some of the earliest fishing hooks to have been retrieved from an archaeological site. Harpoons have a much longer ancestry, being in use in Europe at least 13,000 years ago, and there is evidence for the use of nets in the Middle East as early as 11,000 years ago. It has been suggested that the hunter gatherer economy is not only an efficient strategy, but that in prehistoric times the resources to be exploited were much more abundant than today. There is therefore the need to question why it should be that the economy should shift to one that required a much larger energy expenditure to achieve subsistence requirements, and in which the plant and animal exploitation was limited to a very small number of species. Such a change would not only have limited the cuisine, but also made the economy much more susceptible to environmental and other changes, which is at first glance a retrogressive step in terms of species survival. This last point is highlighted in modern Africa, where the hunter gatherers might be experiencing leaner times, but where the short-term climatic conditions have had a devastating effect on both the pastoralist and agricultural communities, who have a negligible safety margin within their territory. It has been argued that it was the development of the social complexity of the human species that allowed the transition to be made. Alternatively, population pressures may have forced the change. Whether this pressure was AGRICULTURE 767 increased by an actual rise in population numbers, or whether changes in climate reduced the biomass available to an existing population, once the transition had been made it was very difficult, though not impossible, to revert. Once the change had been made, the group could persist as an unstratified society only so long as the availability of land matched the population being supported by it. However, when the stage was reached when marginal land had to be exploited, and to do so a sophisticated technology such as irrigation was required, it would appear that social stratification began to appear within that society. The division may have been wealth, but it was later to be one of specialization, since as communities expanded, so certain groups within those communities became increasingly divorced from the production of food. ARABLE FARMING Irrigation In order to raise crops, there is a need to manipulate water supplies whenever land in less favourable climates is settled. By its nature water is an awkward commodity to transport artificially, and therefore early crop husbandry was confined to those areas with a regular and dependable rainfall, or to areas very close to river systems. Some of these rivers flooded seasonally, and in the case of the Nile or Euphrates this fact was exploited to take advantage of the water dispersed in this way, and also of the fertile silt that was left behind as the waters receded. In areas as flat as the large river basins, the need to trap this seasonal flood water was realized, and lagoons were created from which the water could gradually be released as and when it was required. There is evidence that this practice had been established by the second millennium in Egypt. The system was dependent on the understanding and political control of extensive distances of the river system, and also required an administrative system, not only to organize the building in the first place, but also to control the release and fair distribution of the water. These were prerequisites for any irrigation scheme, and imply the establishment of an already structured society before the expansion of agriculture into less favoured territory could take place. Irrigation takes many forms, each determined by the nature of the land, or the source of water being exploited. In hilly regions the construction of terraces will slow down the normal passage of water en route to the river basin. The size of a terrace field will be determined by the steepness of slope on which it is built, but even in gentle terrain it has been found that an area of about one sixth of an acre is the optimum if critical levels of fall are to be maintained. Extensive terrace systems appear to have been established in China by the Han PART FIVE: TECHNOLOGY AND SOCIETY 768 period, where they are associated with wet rice farming. Similar systems existed throughout Asia, either fed from natural streams, or by artificial canal networks. For scale and age the Chinese canals surpass any others in the world (see p. 474–5), but there were also extensive projects in widely differing geographical regions. An extensive system of canals was begun in antiquity and completed about AD 500 to connect the Euphrates and Tigris river systems, and irrigate the lands that lay between them. In South America, also, there is evidence of early irrigation practices, systems being established in Peru, for example, by the second century. Irrigation is not simply the process of releasing controlled volumes of water on to land, but carries major difficulties because of the high mineral content of the water. Salination is one of the problems, and it is possible that the decline of Sumerian power in what is now southern Iraq, which began in about 2400 BC, was caused by the decline in wealth brought about by a faltering agriculture. Babylon became dominant in the area about 1700 BC, but its power may also have been undermined as the problem moved gradually northwards along the river system. Ground water is also a source for irrigation schemes, and its retrieval may be seen in the qanat system in Iran, to which the Assyrian King Sargon made reference as early as the seventh century BC. It consists of deep, slightly inclining tunnels, connecting an underground highland water source with fields lying many miles below. Such systems still exist in Pakistan, Iran, Iraq, Syria and southern regions of the USSR. Soil preparation To achieve the optimum growth from a seed it must be planted at a specific depth in soil which has been prepared in such a way that it contains a fine structure of particles, enclosing sufficient air and water for the needs of the young seedling. In addition the ground should be free of unwanted plants which may compete with the desired crop, and also free from plants or debris from the previous crop, particularly if the crop is sown more than once in succession, since there is then the danger of disease transfer. The desired conditions may be achieved in a number of ways, perhaps the simplest of which is by turning the soil with a spade to break up and invert the fresh ground, and then pounding the clods in some way, so as to produce the fine tilth required. Spade cultivation is still carried out in many parts of the world, and can be a very efficient form of production. It is ideally suited to the cultivation of small plots of land, whether these be cottage gardens, or terrace strips whose size is dictated by the steepness of the slope on which they lie. However, where larger tracts of land are available speed can only be achieved by using large AGRICULTURE 769 numbers of people, and the depth of cultivation is controlled by the strength of the human frame. With the extra power available from animals, combined with a tool formed to utilize it, there was a significant benefit to be derived not only from the increase in acreage which might be cultivated, but also from the speed with which this acreage could be tackled. In its simplest form the tool need be no more than a suitably shaped branch. All that was required was a pointed part, the share, which would enter the ground and disturb the soil as it passed through it, a handle so that the share could be guided, and lastly a beam to which the draught animal could be attached. The required shape could be obtained by the careful selection of timber, or by joining several pieces of wood together. Unfortunately, since wood is perishable, the evidence which exists for the earliest ploughs is very limited, and its date of origin is therefore difficult to determine. The earliest known representation of a plough was found at the site of Uruk in Iraq, and dates to the third millennium. The actual examples preserved by and found in the peat bogs of Europe date to about two and a half thousand years ago. These are not the earliest known evidence for cultivation implements since a piece found in Satrup Moor in Jutland dates to about six thousand years ago. This seems likely to have been drawn with human muscle power, and cannot therefore be classified as a plough. These very early examples are not true ploughs, but are known as ards. They lack the piece known as a mouldboard, which projects from the side of the implement and serves to lift and turn the soil as the plough passes through. The ard is ideally suited to light sandy soils through which it can be passed frequently to produce the correct tilth without causing excessive water loss. It is therefore still an extremely useful tool under arid conditions, and can be found in many areas of the Mediterranean and Middle East. For heavier soils the mouldboard is an essential requirement, and the exploitation of these soils was delayed until its development shortly before the Roman period. The development of the ard and plough were of significance because of the extension in cultivated acreages that they made possible. Not only were substantial increases in the carrying capacity of the land achieved but, perhaps more significantly, it allowed for the production of food by a smaller percentage of the population. While cereal production had been practised for a considerable time without the use of the plough, once it had been invented, and once the package of cereal and plough had become established, the diffusion of cereals was almost without exception accompanied by the diffusion of the plough and animal traction. Thus it would appear that both cereals and the plough arrived together in India about 4500 BC, and in moving further east arrived in China about 4000 BC. The plough also moved westwards from the Middle East, if indeed that is where it originated, but although apparently traceable to the PART FIVE: TECHNOLOGY AND SOCIETY 770 common form, its subsequent development was to take a very different track from that of the eastward moving counterpart. In China the problem of soil friction against the wooden plough parts was solved with the introduction of metal facings. One of the most significant parts to be protected was the mouldboard, which by the early Han period, that is by about 200 BC, was frequently made with metal alone. With this material they were able to produce it in a curved form, thus achieving a great reduction in the friction and therefore the draught required to pull the plough through the soil. In Europe stones embedded into the wood of the plough were the original solution to the problem of wear, and this practice continued well into the mediaeval period. The mouldboard developed in Europe was made with an unshaped piece of wood, and although it achieved the desired effect, it did so at huge cost in the increase in friction and therefore the animal power required to pull it. It would appear that the introduction of metal facings on to the woodwork of the mouldboard did not occur in Europe until the eighteenth century. There is no proof of connection, but it is part of the curious coincidence that the Jesuit and other European contacts with China should occur at the same time as numerous developments were appearing in agricultural technology in Europe during the Age of Enlightenment. The early European ploughs frequently shown in mediaeval illustrations as clumsy wheeled implements pulled by up to eight oxen certainly existed, but lighter ploughs which could be pulled by small draught teams were also much in evidence, particularly on lighter soils. Their rectangular construction so apparent in the illustrations of the time, left a lot to be desired, but little attempt was made to improve on it until the eighteenth century. In 1730 there appeared in England a plough that has become known as the Rotherham plough, but also carries the name of the Dutch plough, perhaps as an indication of an earlier ancestry. This plough had a triangular framed construction which made it not only lighter but also very much stronger. It was this basic design that the Scottish engineer James Small was to use for his calculations on plough design, and particularly on the design for the mouldboard in ‘A Treatise on Ploughs and Wheeled Carriages’ (1784). James Small was one of the earliest people to apply scientific methods to plough design and it was on the basis of his calculations that the form of the curved mouldboard became established. The efficiency and design of the curved mouldboard, particularly the low draught requirements that it allowed, were to reduce the number of animals required for traction, and therefore the amount of land that was needed to feed them. The very discovery of this device in China is perhaps the reason why the Chinese were to develop a dry land farming that was so little dependent on animal power, and was therefore able to support a much larger population within a given area of land. Despite the advances represented by the Rotherham plough and those that followed it, the wooden plough was difficult and slow to produce and AGRICULTURE 771 impossible to reproduce accurately in every detail. In 1808, Robert Ransome patented the first of his all-metal ploughs. He also introduced the concept of easily interchangeable parts, which greatly simplified the task for the ploughman who was faced with breakages or misalignments. Ransome was to follow this patent with many others of significance, not the least of which was the discovery that if, in the casting of a metal share, one area of the casting was allowed to cool more quickly than another, then a difference in hardness would be induced between these two parts. When in use the parts in question would wear at different rates and by the careful design of the casting, the share could be made to be self sharpening, thus removing one of the more tedious tasks that faced the ploughman during the course of a working day. Changes in the finer detail have occurred but the working parts of the plough have changed little from these nineteenth-century developments. Even for the modern tractor plough the parts that actually work the soil, as against those parts that support them, have changed so little that the names are generally interchangeable between the old and new ploughs. What has changed with the coming of the tractor (see p. 788), and the plough that has been specifically designed for use with it, is not only the increase in area that can be covered in a given time, but also a great increase in the accuracy with which this ploughing is carried out. Hydraulic lift mechanisms on the tractor can be set in such a way that the depth ploughed is very tightly controlled despite changes in the topography of the land or in the hardness of the soil. Despite its long association with cultivation, the plough has passed through a number of phases in its popularity. It has been argued that the slow process of turning the soil is unnecessary and that it is frequently a threat to scarce soil moisture and structure. The argument has perhaps more validity today when the sophistication of herbicide sprays can eliminate the majority of weeds whose destruction is frequently cited as the main function of the plough. The design of the mouldboard is such that it will always turn the soil over in one direction. Changes in design, whether for the horse-drawn or the tractordrawn plough, have been brought about in the attempt to increase the productivity of the implement. The longer the working parts are in the soil, and turning the soil, the more work is achieved. Ideally, therefore, the greater the ratio of the field’s length to its width, the less time will be wasted in turning the plough at the end of one bout ready for the trip back down the field. With the mouldboard fixed to one side of the plough this efficiency was achieved by ploughing in long strips, beginning at what would be the centre of the strip, and gradually working away from that centre, until the time taken to cross from one bout to another became too great, and a new strip was begun, lined up so that it would eventually join with the first. This method, when repeated in exactly the same place each year, resulted in alternate peaks and troughs of land. The practice was encouraged on heavy clay lands since it greatly improved the drainage, and therefore made them more productive. The . with many others of significance, not the least of which was the discovery that if, in the casting of a metal share, one area of the casting was allowed to cool more quickly than another, then. also allows for the plant gathering element of the economy to move to a settled regime, planting and harvesting crops, and exploiting the animals for both their strength and their manure. However,. in the other direction. PART FIVE: TECHNOLOGY AND SOCIETY 766 Fishing The cultivation and harvest of domestic plants implies the existence of settled communities if only because the storage of