To know the number of houses, I used three methods, viz. -

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.