as the expected profits of the voyage.
[Footnote 41: "An estimate of a voyage from Rhode Island to the Coast of Guinea and from thence to Jamaica and so back to Rhode Island for a sloop of 60 Tons." The authorities of Yale University, which possesses the manuscript, have kindly permitted the publication of these data.

The estimates in Rhode Island and Jamaica currencies, which were then depreciated, as stated in the document, to twelve for one and seven for five sterling respectively, are here changed into their approximate sterling equivalents.] As to the gross volume of the trade, there are few statistics.

As early as 1734 one of the captains engaged in it estimated that a maximum of seventy thousand slaves a year had already been attained.[42] For the next half century and more each passing year probably saw between fifty thousand and a hundred thousand shipped.

The total transportation from first to last may well have numbered more than five million souls.

Prior to the nineteenth century far more negro than white colonists crossed the seas, though less than one tenth of all the blacks brought to the western world appear to have been landed on the North American continent.