William Petty,
Observations upon the Dublin Bills of Mortality…
(1899)
“ The London-Observations reckon eight heads in each Family [11] ; according to which estimation, there are 32000 Souls [12] in the 4000 Families of Dublin; which is but half of what most Men imagine; of which but about one sixth part are able to bear Arms, besides the Royal Regiment. 6. Without the knowledge of the true number of People, as a Principle, the whole scope and use of the keeping Bills of Births and Burials is impaired; wherefore by laborious Conjectures and Calculations to deduce the number of People from the Births and Burials, may be Ingenious, but very preposterous. ”
