ABSTRACT
William Petty was involved, during the English Interregnum under Oliver Cromwell in the 1650s, with land surveying and management in Ireland, to which he returned in the 1660s, having become a Fellow of the Royal Society. In that same decade he applied the principles of numerical analysis to social data in his celebrated Political Arithmetick. Closely contemporary with Petty's work, John Graunt published in 1662 a work based on the Bills of Mortality for London, investigating demographic data and the statistical conclusions that might be drawn from them. In the present extract from Petty, Petty considers the population of London and its historical development, as well as of the nation as a whole, on the basis of available estimated data and principles of population increase. As for the time in which the People double, it is yet more hard to be found.
