A, B, C, D, E represent the several stages through which the raw material obtained from Nature passes on its way to the position of a consumer's utility. The five stages represent the five leading processes in production--the extractive process, transport, manufacture, wholesale and retail trade. The raw materials extracted at A, the wheat, skins, iron, timber, cotton, etc., obtained from various quarters of the globe, are gathered together in large quantities into places where they undergo various transformations of shape and character; they are then distributed by wholesale and retail merchants, who hand them over to persons who consume them as bread, boots, kettles, chairs, shirts. The extractive, transport, manufacturing, and merchant stages may of course be subdivided into many complex processes, as applied to the history of the more elaborately-produced commodities. But at each point in the process of production there must stand a quantity of plant and machinery designed to assist in moving the productive goods a single step further on the road towards consumption. This fixed capital is denoted by the black circles placed at the points A, B, C, D, E. But each machine, or factory building, or warehouse is itself the ultimate product of a series of steps which constitute a process similar to that denoted by the main channel of production. Consisting in raw material extracted from nature, the machinery and plant are built up by a number of productive stages, which correspond to A, B, C, D, E, into the completed shapes of fixed capital, adjusted to the positions where they can give the proper impulse to the main tide of production. Each productive stage in the production of plant or machinery requires the presence of other plant and machinery to assist its progress. Each of these secondary forms of fixed capital situate at _a_, _b_, _c_, _d_, _e_, has of course a similar history of its own. To represent the full complexity of the mechanism of industry thus suggested would be confusing and would serve no purpose here. It is sufficient that we recognise that at each point A, B, C, D, E, and at each of the points _a_, _b_, _c_, _d_, _e_, upon the perpendicular lines, stands a quantity of forms of fixed capital which are gradually worn out in the work of forwarding quantities of A to B, and quantities of B to C, and so on. Now if we turn to the point F, where goods pass out of the productive machine into the hands of consumers, who destroy them by extracting their "utility or convenience," we shall find in this flow of goods out of the industrial machine the motive-force and regulator of the activity of the whole machine.