text:  It may be fairly assumed that on the average the shipping in foreign trade make one and a half voyages outwards--that is outwards and inwards together three voyages in the year; for upon a rough estimate it would appear that not one-tenth of this shipping was occupied in mercantile enterprise beyond the limits of that narrower circle before assigned ad within which repeated voyages of twice and thrice in the year and frequently more often are not practicable only but habitually performed