[Footnote 9:  Mungo Park, Travels in the Interior Districts of Africa (4th ed., London, 1800), pp. 287, 428.]

The diverse goods bartered for slaves were rated by units of value which varied in the several trade centers.  On the Gold Coast it was a certain length of cowrie shells on a string; at Loango it was a “piece” which had the value of a common gun or of twenty pounds of iron; at Kakongo it was twelve- or fifteen-yard lengths of cotton cloth called “goods";[10] while on the Gambia it was a bar of iron, apparently about forty pounds in weight.  But in the Gambia trade as Moore described it the unit or “bar” in rum, cloth and most other things became depreciated until in some commodities it was not above a shilling’s value in English money.  Iron itself, on the other hand, and crystal beads, brass pans and spreadeagle dollars appreciated in comparison.  These accordingly became distinguished as the “heads of goods,” and the inclusion of three or four units of them was required in the forty or fifty bars of miscellaneous goods making up the price of a prime slave.[11] In previous years grown slaves alone had brought standard prices; but in Moore’s time a specially strong demand for boys and girls in the markets of Cadiz and Lisbon had raised the prices of these almost to a parity.  All defects were of course discounted.  Moore, for example, in buying a slave with several teeth missing made the seller abate a bar for each tooth.  The company at one time forbade the purchase of slaves from the self-styled Portuguese because they ran the prices up; but the factors protested that these dealers would promptly carry their wares to the separate traders, and the prohibition was at once withdrawn.

[Footnote 10:  The Abbe Proyart, History of Loango (1776), in Pinkerton’s Voyages, XVI, 584-587.]

[Footnote 11:  Francis Moore, Travels in Africa, p.45.]

The company and the separate traders faced different problems.  The latter were less easily able to adjust their merchandise to the market.  A Rhode Island captain, for instance, wrote his owners from Anamabo in 1736, “heare is 7 sails of us rume men, that we are ready to devour one another, for our case is desprit”; while four years afterward another wrote after trading at the same port, “I have repented a hundred times ye lying in of them dry goods”, which he had carried in place of the customary rum.[12] Again, a veteran Rhode Islander wrote from Anamabo in 1752, “on the whole I never had so much trouble in all my voiges”, and particularized as follows:  “I have Gott on bord 61 Slaves and upards of thirty ounces of Goold, and have Gott 13 or 14 hhds of Rum yet Left on bord, and God noes when I shall Gett Clear of it ye trade is so very Dull it is actuly a noof to make a man Creasey my Cheef mate after making foor or five Trips in the boat was taken Sick and Remains very bad yett then I sent Mr. Taylor, and he got not well, and three more of my men has [been] sick....  I should be Glad I coold Com Rite home with my slaves, for my vesiel will not Last to proceed farr we can see Day Lite al Roond her bow under Deck.... heare Lyes Captains hamlet, James, Jepson, Carpenter, Butler, Lindsay; Gardner is Due; Ferguson has Gone to Leward all these is Rum ships."[13]