[ 270 ] 
four births, at an average, as Dr. Derham, Major 
Graunt, and others have fhewn, and which I have 
found to be true from theRegifters both in the Town 
and Country ; then confequently, allowing for deaths, 
there cannot be tnree children that furvive, from every 
marriage to mature age, and indeed not much above 
two, as appears from Dr. Halley’s Table of the pro- 
bability of life. And therefore every family, where 
there are children, one with another, cannot confift 
of more than between four and five perfons, befides 
fervants or inmates ; which fliews plainly that fami- 
lies, where there are children, cannot be elfimated at 
more than fix to a houfe, and where there are no 
children, they cannot be reckoned more at an average. 
The number then being fix to be afiumed, let us 
next confider what number of houfes is to be fuppofed. 
That I might come at fome certainty in this I lately 
applied to one of the Public Offices, where I thought 
they could very likely give me an account of thefn ; 
and I there found, that before the year 1710, and 
near about that time, an account had been taken of 
all the houfes throughout England and Wales, in or- 
der for fome Aflefiment upon them j and the number 
then did amount to 729048. In which it may be 
fuppofed, that a number of Cottages were omitted, 
that might be improper for that Afieffiment ; but I 
think there could not poffibly be above one-fourth 
part of that number more: Forfurely the Surveyors, 
if they had any care of the Public Revenue, would 
never omit above one in Five. Let us therefore fup- 
pofe, that there might be one- fourth part of that 
number more j and then thofe omitted will be about 
182262, and the whole number of houfes could not 
exceed 911310. 
If 
