A moderate computation of the expences in provisions, spent in the cities of London and Westminster [electronic resource] : and the places within the weekly bills of mortality, for a year, month, week, day, hour and minute, founded upon this modest supposition, that there may be but [a] million of people within the said cities and weekly bills of mortality, observed by a scrutinous enquiry i[n] most of the particulars / by John Seller, Sen.