The last machine which we shall mention is connected with the greatest of all improvements in the crop-producing power of British land--the system of tile-draining. Pipes are now made by machinery; and land may be effectually drained at a cost of 4_l._ per acre. [Illustration: Draining-tile machine.] The farmers of England have made what we may fairly call heroic efforts to meet foreign competition; but their efforts would have been comparatively vain had science not come to the aid of production. According to the Census of 1851, the total population of Great Britain is 20,959,477--in round numbers, twenty-one millions. In the 'Return of Occupations,' one-half of this entire population is found under the family designation--such as child at home, child at school, wife, daughter, sister, niece, with no particular occupation attributed to them. They are important members of the state; they are growing into future producers, or they preside over the household comforts, without which there is little systematic industry. But they are not direct producers. Of this half of the entire population, one-fifth belong to the class of cultivators, viz.:-- Male. Female. Holders of farms 275,676 28,044 Farmers' relatives, in-door 137,446 Out-door labourers 1,006,728 70,899 Farm-servants, in-door 235,943 128,251 Shepherds, out-door 19,075 Woodmen 9,832 Gardeners 78,462 2,484 Farm bailiffs 12,805 Graziers 3,036 ____________ __________ 1,779,003 229,678 This total (in which we omit the farmers' wives and daughters, amounting to about 240,000) shows that one-fifth of the working population provide food, with the exception of foreign produce, for themselves and families and the other four-fifths of the population. Such a result could not be accomplished without the appliances of scientific power which we have described in this chapter. In the early steps of British society a very small proportion of labour could be spared for other purposes than the cultivation of the soil. It has been held that a community is considerably advanced when it can spare one man in three from working upon the land. Only twenty-six per cent of our adult males are agricultural--that is, three men labour at some other employment, while one cultivates the land. During the last forty years the proportion of agricultural employment, in comparison with manufacturing and commercial, has been constantly decreasing; and is now about twenty per cent., whereas in 1811 it was thirty-five per cent. of all occupations. [17] Cullum's 'History of Hawsted.' [18] See various tables in Porter's 'Progress of the Nation.'