The Wealth of Nations by Part 4 Chapter 7 Page 146

All the purposes of this trade being, in this manner, answered by a much smaller capital, there would have been a large spare capital to apply to other purposes: to improve the lands, to increase the manufactures, and to extend the commerce of Great Britain; to come into competition at least with the other British capitals employed in all those different ways, to reduce the rate of profit in them all, and thereby to give to Great Britain, in all of them, a superiority over other countries still greater than what she at present enjoys.

The monopoly of the colony trade, too, has forced some part of the capital of Great Britain from all foreign trade of consumption to a carrying trade; and consequently, from supporting more or less the industry of Great Britain, to be employed altogether in supporting partly that of the