From 1694 to Plassey, the growth had been relatively slow. For more than sixty years after the foundation of the Bank of England, its smallest note had been for £20, a note too large to circulate freely, and which rarely travelled far from Lombard Street. Writing in 1790, Burke mentioned that when he came to England in 1750 there were not “twelve bankers’ shops” in the provinces, though then, he said, they were in every market town.[340] Thus the arrival of the Bengal silver not only increased the mass of money, but stimulated its movement; for at once, in 1759, the bank issued £10 and £15 notes, and, in the country, private firms poured forth a flood of paper. At the outbreak of the Napoleonic wars, there were not far from four hundred provincial houses, many of more than doubtful solvency. Macleod, who usually does not exaggerate such matters, has said, that grocers, tailors, and drapers inundated the country with their miserable rags.[341] The cause of this inferiority of the country bankers was the avarice of the Bank of England, which prevented the formation of joint stock companies, who might act as competitors; and, as the period was one of great industrial and commercial expansion, when the adventurous and producing classes controlled society, enough currency of some kind was kept in circulation to prevent the prices of commodities from depreciating relatively to coin. The purchasing power of a currency is, other things being equal, in proportion to its quantity. Or, to put the proposition in the words of Locke, “the value of money, in general, is the quantity of all the money in the world in proportion to all the trade.”[342] At the close of the eighteenth century, many causes combined to make money plentiful, and therefore to cheapen it. Not only was the stock of bullion in England increased by importations from India, but, for nearly a generation, exports of silver to Asia fell off. From an average of £600,000 annually between 1740 and 1760, the shipments of specie by the East India Company fell to £97,500 between 1760 and 1780; nor did they rise to their old level until after the close of the administration of Hastings, when trade returned to normal channels. After 1800 the stream gathered volume, and between 1810 and 1820 the yearly consignment amounted to £2,827,000, or to nearly one-half of the precious metals yielded by the mines.