At first Spain tried to exclude foreigners from this most lucrative traffic; but here again the English moved too quickly to be stopped. Wherever Hawkins went, he went prepared to fight, and, if prevented from trading peaceably, he used force. In his first voyage he met with no opposition, but subsequently, at Burburata, leave to sell was denied him, and, without an instant’s hesitation, he marched against the town with “a hundred men well armed,” and brought the governor to terms. Having supplied all the slaves needed at that port, Hawkins went on to Rio de la Hacha, where he, in like manner, made a demonstration with “one hundred men in armour,” and two small guns, and in ten days he had disposed of his whole stock. As at that time an able negro appears to have been worth about £160 in the West Indies,[316] a cargo of five hundred ought to have netted between seventy and eighty thousand pounds, for the cost of kidnapping was trifling. No wonder, therefore, that slaving flourished, and that, by the middle of the eighteenth century, England probably carried not far from one hundred thousand blacks annually from Africa to the colonies. The East offered no such market, and doubtless Adam Smith was right in his opinion that the commerce with India had never been so advantageous as the trade to America.[317] Both slavers and pirates brought bullion to England, and presently this flow of silver began to stimulate at London a certain amount of exchange between the East and West. The Orientals have always preferred payment in specie, and, as silver has usually offered more profit than gold as an export, the European with a surplus of silver has had the advantage over all competitors. Accordingly, until Spain lost the power to protect her communications with her mines, the Spanish peninsula enjoyed almost a monopoly of the trade beyond the Cape; but as the war went on, and more of the precious metal flowed to the north, England and Holland began to send their silver to Asia, the Dutch organizing one East India Company in 1595, and the British another in 1600. Sir Josiah Child, who was, perhaps, the ablest merchant of the seventeenth century, observed that in 1545 “the trade of England then was inconsiderable, and the merchants very mean and few.”[318] Child’s facts are beyond doubt, and the date he fixed is interesting because it coincides with the discovery of Potosi, whence most of the silver came which supplied the pirates and the slavers. Prior to 1545 specie had been scarce in London, but when the buccaneers had been scuttling treasure galleons for a generation, they found themselves possessed of enough specie to set them dreaming of India, and thus piracy laid the foundation of the British empire in Asia.