But more significant than these changes was the rise of the so-called mercantile system, in which the state took under its care industrial details that were formerly regulated by the town or guild. This system, beginning in the sixteenth century and lasting through the eighteenth, had for its prime object the upbuilding of national trade. The state, in order to insure the homogeneous development of trade and industry, dictated the prices of commodities. It prescribed the laws of apprenticeship and the rules of master and servant. It provided inspectors for passing on the quality of goods offered for sale. It weighed the loaves, measured the cloth, and tested the silverware. It prescribed wages, rural and urban, and bade the local justice act as a sort of guardian over the laborers in his district. To relieve poverty poor laws were passed; to prevent the decline of productivity corn laws were passed fixing arbitrary prices for grain. For a time monopolies creating artificial prosperity were granted to individuals and to corporations for the manufacture, sale, or exploitation of certain articles, such as matches, gunpowder, and playing-cards. This highly artificial and paternalistic state was not content with regulating all these internal matters but spread its protection over foreign commerce. Navigation acts attempted to monopolize the trade of the colonies and especially the trade in the products needed by the mother country. England encouraged shipping and during this period achieved that dominance of the sea which has been the mainstay of her vast empire. She fostered plantations and colonies not for their own sake but that they might be tributaries to the wealth of the nation. An absurd importance was attached to the possession of gold and silver, and the ingenuity of statesmen was exhausted in designing lures to entice these metals to London. Banking and insurance began to assume prime importance. By 1750 England had sent ships into every sea and had planted colonies around the globe. But while the mechanism of trade and of government made surprising progress during the mercantile period, the mechanism of production remained in the slow handicraft stage. This was now to change. In 1738 Kay invented the flying shuttle, multiplying the capacity of the loom. In 1767 Hargreaves completed the spinning-jenny, and in 1771 Arkwright perfected his roller spinning machine. A few years later Crompton combined the roller and the jenny, and after the application of steam to spinning in 1785 the power loom replaced the hand loom. The manufacture of woolen cloth being the principal industry of England, it was natural that machinery should first be invented for the spinning and weaving of wool. New processes in the manufacture of iron and steel and the development of steam transportation soon followed.