A radical change in the mode of production in one sphere of industry
 involves a similar change in other spheres. This happens at first in such
 branches of industry as are connected together by being separate phases
 of a process, and yet are isolated by the social division of labour, in
 such a way, that each of them produces an independent commodity. Thus spinning
 by machinery made weaving by machinery a necessity, and both together made
 the mechanical and chemical revolution that took place in bleaching, printing,
 and dyeing, imperative. So too, on the other hand, the revolution in cotton-spinning
 called forth the invention of the gin, for separating the seeds from the
 cotton fibre; it was only by means of this invention, that the production
 of cotton became possible on the enormous scale at present required. [19] But more especially, the revolution in the modes of production of industry and agriculture made necessary a revolution in the general conditions of
 the social process of production, i.e., in the means of communication and
 of transport. In a society whose pivot, to use an expression of Fourier,
 was agriculture 363on a small scale, with its subsidiary domestic
 industries, and the urban handicrafts, the means of communication and transport
 were so utterly inadequate to the productive requirements of the manufacturing
 period, with its extended division of social labour, its concentration
 of the instruments of labour, and of the workmen, and its colonial markets,
 that they became in fact revolutionised. In the same way the means of communication
 and transport handed down from the manufacturing period soon became unbearable
 trammels on modern industry, with its feverish haste of production, its
 enormous extent, its constant flinging of capital and labour from one sphere
 of production into another, and its newly-created connexions with the markets
 of the whole world. Hence, apart from the radical changes introduced in
 the construction of sailing vessels, the means of communication and transport
 became gradually adapted to the modes of production of mechanical industry,
 by the creation of a system of river steamers, railways, ocean steamers,
 and telegraphs. But the huge masses of iron that had now to be forged,
 to be welded, to be cut, to be bored, and to be shaped, demanded, on their
 part, cyclopean machines, for the construction of which the methods of
 the manufacturing period were utterly inadequate.