We thus see in the several departments of industry, under the pressure of the same economic forces, an expansion of size, a growing complexity of structure and functional activity, and an increased cohesion of highly differentiated parts in the business, the market, and in that aggregation of related trades and markets which forms the world-industry. The physical instrument by which these economic forces, making for increased size, heterogeneity, and cohesiveness,[123] have been able to operate is machinery applied to manufacture and transport. Moreover, each new encroachment of machinery upon the extractive and the distributing industries brings into prominence within these processes the same structural and functional characteristics. [Illustration: COMPARATIVE VALUE OF FOREIGN TRADE IN EUROPEAN COUNTRIES.] FOOTNOTES: [99] Cf. Chap. VI. for a discussion of this equation of maximum profit. [100] _Report to Labour Commission on Employment of Women_ (1893), p. 125. [101] _Statistical Abstract_, 1878-92, p. 182 [102] _Social Peace_, p. 126; cf. also Brentano, _Hours, Labour, and Production_, p. 60. [103] _Contemporary Review_, 1889, p. 394. [104] Porter, _Progress of the Nation_, p. 216. [105] _Principles of Economics_, 2nd edit., p. 282. [106] Schulze-Gaevernitz, _Der Grossbetrieb_, p. 90. [107] Marshall, _Principles of Economics_, 2nd edit., p. 283. [108] The works of Messrs. Colman, at Norwich, comprise among others the following subsidiary departments:--Coopery, engineering shop, saw mills, box-making, packing, paper-making, printing, laboratory. To the most highly developed businesses of pottery and machine-making schools of art and design are not uncommonly attached. [109] A good deal of the cleansing and combing in the cloth and worsted trades is, however, done separately on commission by large firms such as Lister's. Cf. Burnley, p. 417. [110] Marshall, _Principles of Economics_, 2nd edit., p. 517. [111] Cournot, _Recherches sur les Principes Mathématiques de la Theorie des Richesses_ (quoted Marshall, _Principles of Economics_, p. 384). [112] It ought, however, to be kept in mind that the application of the "roundabout" method is only economically justified by a continual increase in consumption. So far as a given quantity of consumption is concerned the result of the "roundabout" method is to diminish the quantity of capital which assists to produce it. [113] Professor Böhm Bawerk shows this increased time of production to be the essential characteristic of capitalist production. Cf. _Positive Theory of Capital_. [114] For a full and valuable treatment of these harmonious relations, from the point of view of consumption and production, see Patten's _Economics of a Dynamic Society_. [115] Cf. Porter, _Progress of the Nation_, pp. 177-206. [116] _Principles of Sociology_, vol. i. p. 500 (3rd edit.). [117] For a detailed account of the national trade divisions, cf. Dr. Yeats, _The Golden Gates of Trade_.