[ 337 3 
<e with eafe, by taking, in the whole extent of life, 
(c feveral intervals, whether equal or unequal. How- 
tc ever, before I undertook the talk, I tried what 
“ would be the refult of fuppofing thofe decre- 
“ ments uniform from the age of twelve j being 
<c fatisfied, that the exceffes on one fide would be 
u nearly compenfated by the defeats on tlie other : 
<c then, comparing my calculation, with that of Dr. 
a Halley, I found the conclufion fo very different, 
u that I thought it fuperfluous to join together feveral 
<c different rules, in order to compofe a fingle one/’ 
Now the fame thing, which Mr. De Moivre 
mentions above, happens in the table of the London 
obfervations ; viz. out of yio perfons, of 12 years of 
age, there remain 504, after one year; 498, after 
two years ; 402, 486, 480, 474, 468, 462, after 
3, 4, 5, 6, 7, and 8 years refpedtively ; the com- 
mon difference being 6 ; and the like happens in 
other inftances, to be met with in the London ob- 
fervations, as published by different authors. Add 
to this, that, having calculated the value of an an- 
nuity on a life of 10 years of age, by both tables, and 
alfo by the hypothecs, I find it to turn out thus, 
Years Parchafc. 
By the Breflaw tables of obfervations 1 7,7 237 
By fuppofing the decrements of lifeequal 16,88 14 
By the London tables of obfervations 16,3907 
From which there fieems to be fome reafon to con- 
clude, that the hypothecs (as it gives an anfwer lefg 
than the Breflaw, and greater than the London ob- 
fervations) may be the beft method of the three; 
And it is farther remarkable, that the refult, by th« 
U 11 - hypothetic, 
