12. Paris hath not been for these last fifty years so much infested with the plague as London; now that at London the plague (which between the years 1591 and 1666 made five returns, viz., every fifteen years, at a medium, and at each time carried away one-fifth of the people) hath not been known for the 21 years last past, and there is a visible way by God’s ordinary blessing to lessen the same by two-thirds when it next appeareth. 13. As to the ground upon which Paris stands in respect of London, we say, that if there be five stories or floors of housing at Paris, for four at London, or in that proportion, then the 82,000 families of Paris stand upon the equivalent of 65,000 London housteds, and if there be 115,000 families at London, and but 82,000 at Paris, then the proportion of the London ground to that of Paris is as 115 to sixty-five, or as twenty-three to thirteen. 14. Moreover Paris is said to be an oval of three English miles long and two and a half broad, the area whereof contains but five and a half square miles; but London is seven miles long, and one and a quarter broad at a medium, which makes an area of near nine square miles, which proportion of five and half to nine differs little from that of thirteen to twenty-three. 15. Memorandum, that in Nero’s time, as Monsieur Chivreau reporteth, there died 300,000 people of the plague in old Rome; now if there died three of ten then and there, being a hotter country, as there dies two of ten at London, the number of people at that time, was but a million, whereas at London they are now about 700,000. Moreover the ground within the walls of old Rome was a circle but of three miles diameter, whose area is about seven square miles, and the suburbs scarce as much more, in all about thirteen square miles, whereas the built ground at London is about nine square miles as aforesaid; which two sorts of proportions agree with each other, and consequently old Rome seems but to have been half as big again as the present London, which we offer to antiquaries. THE THIRD ESSAY. PROOFS that the number of people in the 134 parishes of the London bills of mortality, without reference to other cities, is about 696,000, viz.— I know but three ways of finding the same. 1. By the houses, and families, and heads living in each. 2. By the number of burials in healthful times, and by the proportion of those that live, to those that die. 3. By the number of those who die of the plague in pestilential years, in proportion to those that escape. _The First Way_. To know the number of houses, I used three methods, viz.—