[ ^22 ] 
to have been, during thefe feven years, looo, and 
the annual births 3000, or an i8th part of the inha- 
bitants. —Similar obfervations may be made on the 
much quicker increafe in Rhode Ifland, as related 
in the preface to Dr. Birch’s collediion of the bills 
of mortality^ and alfo in the valuable pamphlet, laft 
quoted, on the interefi of Great Britain with regard 
to her colonies y p. 36. What a prodigious differ- 
ence muft there be between the vigour and the hap- 
pinefs of human life in fuch fituations, and in fuch 
a place as London?- The original number of 
perfons who, in 1643, had fettled in New England, 
was 21,200. Ever lince it is reckoned, that more 
have left them than have gone to them"*. In 
the year 1760 they were increafed to half a million. 
They have, therefore, all along doubled their own 
number in 25 years 3 and, if they continue to in- 
creafe at the fame rate, they will, 70 years hence, 
in New England alone, be four millions 3 and in all 
North America above twice the number of inhabit- 
ants in Great-Britain -f-. But I am v/andering 
See Dr. Styles’s pamphlet juft quoted, p. no, &c. 
f The rate of increafe, fuppofing the procreative powers the 
fame, depends on two caufes : The “ encouragement to mar- 
“ ria^e i” and the “ expetfation of a child jufl: born.” When 
one of thefe is given, the increafe will be always in proportion 
to the other. That is ; As much greater or Ir.fs as the ratio is of 
the numbers who reach maturity, and of thofe who marry to the 
■ umber born, fb much quicker or Jlower will be the increafe. 
Let us fuppofe the operation of thefe caufes fuch as to produce an 
annual cxcefs of the births above the burials equal to a 3611 part 
of the whole number of inhabitants. It may feem to follow 
from hence, that the inhabitants would double their own number 
in 36 years ; and thus feme have calculated. But the truth is, 
that they would double their own number in much Icfs time. 
from 
