The colony trade, however, it may perhaps be said, is more advantageous to Great Britain than any other; and the monopoly, by forcing into that trade a greater proportion of the capital of Great Britain than what would otherwise have gone to it, has turned that capital into an employment more advantageous to the country than any other which it could have found.
The most advantageous employment of any capital to the country to which it belongs, is that which maintains there the greatest quantity of productive labour, and increases the most the annual produce of the land and labour of that country. But the quantity of productive labour which any capital employed in the foreign trade of consumption can maintain, is exactly in proportion, it has been shown in the second book, to the frequency of its returns. A capital of a thousand pounds, for example, employed in a foreign trade of consumption, of which the returns are made regularly once in the year, can keep in constant employment, in the country to which it belongs, a quantity of productive labour equal to what a thousand pounds can maintain there for a year. If the returns are made twice or thrice in the year, it can keep in constant employment a quantity of productive labour equal to what two or three thousand pounds can maintain there for a year. A foreign trade of consumption carried on with a neighbouring, is, upon this account, in general, more advantageous than one carried on with a distant country; and for the