It is said that Ghana obtained its gold by silent or dumb barter which was described as follows: "The merchants beat great drums to summon the local natives, who were naked and lived in holes in the ground. From these holes, which were doubtless the pits from which they dug the gold, they refused to emerge in the presence of the foreign merchants. The latter, therefore, used to arrange their trade goods in piles on the river bank and retire out of sight. The local natives then came and placed a heap of gold beside each pile and withdrew. If the merchants were satisfied they took the gold and retreated, beating their drums to signify that the market was over."

How Europe Underdeveloped Africa (1972)