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An Encyclopedia of the History of Technology part 82

An Encyclopedia of the History of Technology part 82. This one of a kind encyclopedia presents the entire field of technology from rudimentary agricultural tools to communication satellites in this first of its kind reference source. Following an introduction that discusses basic tools, devices, and mechanisms, the chapters are grouped into five parts that provide detailed information on materials, power and engineering, transportation, communication and calculation, and technology and society, revealing how different technologies have together evolved to produce enormous changes in the course of history | PART FIVE TECHNOLOGY AND SOCIETY The pastoralist whose diet is dependent on the milk products from the flock or herd is perhaps the most precariously balanced exploiter of marginal areas since lactation is so dependent on adequate food and water supply. Left to its own devices it is likely that a human population density will be established which reflects the carrying capacity of the land and the territory in which the shepherd or cattle herder moves. There may be occasional short-term weather changes which cause distress to a community but in general these effects would be local and can be survived because the stocking rate would originally be well below the level supportable within that area. Unfortunately it is only in more recent times that western agencies have recognized the significance of the low stocking rates in terms of a safety net and that the placing of wells and therefore water into areas that had previously been without admittedly increases the carrying capacity of the land but only by making the fall-back area unavailable in bad times. The actual process of removing milk from the animal changed little from the earliest times until well into the twentieth century. Selective breeding has greatly increased the yield from any one animal but while farm labour remained relatively cheap there was little incentive to look for alternatives to hand milking. Although some experiments on vacuum milking machines had been carried out in Britain and America in the 1860s it was not until Murchland s patent in 1889 that a practical machine was developed Figure 16.5 . However the continuous pressure of this machine caused damage to the sensitive udder tissues and it needed Dr Shield s pulsating mechanism to realize the full potential of the idea. Even then hand milking was a continued practice in much of Europe until the middle of the present century. The very perishable nature of milk limited the ways in which it could be exploited in increasingly urban societies.