1. The number of houses which were burnt A.D. 1666, which by authentic report was 13,200; next what proportion the people who died out of those houses, bore to the whole; which I find A.D. 1686, to be but one seventh part, but A.D. 1666 to be almost one-fifth, from whence I infer the whole housing of London A.D. 1666 to have been 66,000, then finding the burials A.D. 1666 to be to those of 1686 as 3 to 4,I pitch upon 88,000 to be the number of housing A.D. 1686. 2. Those who have been employed in making the general map of London, set forth in the year 1682, told me that in that year they had found above 84,000 houses to be in London, wherefore A.D. 1686, or in four years more, there might be one-tenth or 8,400 houses more (London doubling in forty years) so as the whole, A.D. 1686 might be 92,400. 3. I found that A.D. 1685, there were 29,325 hearths in Dublin, and 6,400 houses, and in London 388 thousand hearths, whereby there must have been at that rate 87,000 houses in London. Moreover I found that in Bristol there were in the same year 16,752 hearth; and 5,307 houses, and in London 388,000 hearths as aforesaid; at which rate there must have been 123,000 houses in London, and at a medium between Dublin and Bristol proportions 105,000 houses. Lastly, by certificate from the hearth office, I find the houses within the bills of mortality to be 105,315. Having thus found the houses, I proceed next to the number of families in them, and first I thought that if there were three or four families or kitchens in every house of Paris, there might be two families in one-tenth of the housing of London; unto which supposition, the common opinion of several friends doth concur with my own conjectures. As to the number of heads in each family, I stick to Grant’s observation in page — of his fifth edition, that in tradesmen of London’s families there be eight heads one with another, in families of higher ranks, above ten, and in the poorest near live, according to which proportions, I had upon another occasion pitched the medium of heads in all the families of England to be six and one-third, but quitting the fraction in this case, I agree with Monsieur Auzout for six. To conclude, the houses of London being 105,315 and the addition of double families 10,531 more, in all 115,846; I multiplied the same by six, which produced 695,076 for the number of the people. _The Second Way_. I found that the years 1684 and 1685, being next each other, and both healthful, did wonderfully agree in their burials, viz., 1684 they were 23,202, and A.D. 1685 23,222, the medium whereof is 23,212; moreover that the christenings 1684 were 14,702, and those A.D. 1685 were 14,730, wherefore I multiplied the medium of burials 23,212 by 30, supposing that one dies out of 30 at London, which made the number of people 696,360 souls. Now to prove that one dies out of 30 at London or thereabouts, I say—