Regarding, then, the known and related world of that time in the light of an industrial organism, we must consider it as one in which the processes of integration and of differentiation of parts has advanced but a little way, consisting as yet of a number of homogeneous and incoherent national cells.
This homogeneity is of course qualified by differences in production and consumption due to climate, natural products, national character and institutions, and the development of industrial arts in the several nations.
§ 5. This consideration of the approximate homogeneity of the national units of world-industry gives a higher scientific value to the analysis of a single typical industrial nation such as England, than would be the case in modern times, when the work of differentiation of industrial functions among the several nations has advanced much further.
Taking, therefore, the national industry of England as the special subject of analysis, we may seek to obtain a clear conception of the size, structure, and connections, of the several branches of industry, paying special regard to the manufactures upon which the new industrial forces were chiefly to operate.
It is not possible to form a very accurate estimate of the relative importance of the different industries as measured either by the money value of their products, or by the amount of labour engaged in producing them. Eighteenth century statistics, as we saw, furnished no close estimate of the total income of the nation or of the value of home industries. Since no direct census of the English population was taken before 1805, the numbers were never exactly known, and eighteenth century economists spent much time and ingenuity in trying to ascertain the growth of population by calculations based upon the number of occupied houses, or by generalising from slender and unreliable local statistics, without in the end arriving at any close agreement. Still less reliable will be the estimates of the relative size and importance of the different industries.
Two such attempts, however, one slightly prior to the special period we are investigating, and one a little later, may be taken as general indications of the comparative importance of the great divisions of industry, agriculture, manufacture, distribution or commerce.