 Only the first of these three could be easily verified by empirical findings. Because legal tender was issued by the royal mint, it was possible to estimate the money supply. Hume, for example, claimed that about 90 million pounds circulated in Britain circa 1750. It was much more difficult to measure changes to the price level. Consumer price indexing, a systematic method for measuring inflation that would serve to confirm the quantity theory of money, was first devised in the late nineteenth century and only undertaken by state agencies in the decades after World War One. Nevertheless, early modern economists devised clever means to measure the purchasing power of the currency, whether by examining the price of corn (grains) or looking to other benchmarks. William Fleetwood’s Chronicon Preciosum; or an Account of English Money, the Price of Corn and other Commodities for the last 600 years (1707), proved an invaluable resource. He also made estimates of purchasing power, noting that his stipend as a Fellow of King’s College Cambridge, which had been fixed at five pounds in 1450 ought to be increased to thirty pounds to command the same value. Adam Smith proposed the longterm silver price of corn as the best metric for estimating inflation. His belief was that one must take a weighted average over a longer period of time, 50 to 100 years in order to eliminate the seasonal variations in harvests or isolated discoveries of silver reserves.