[ 66 3 
known, I was afraid that the publ idling of it wouid 
have fwelfd the book too much ; for this reafon 
efpecially, that many corollaries were annexed to 
it. However, I promifed to fend it you in a fhort 
time i but defired you to let me know, whether you 
thought it deferv’d a place in the Fhilofophical Tranf- 
adions. I now difcharge my promife ; and exped, 
with impatience, the favour of your opinion. 1 am, 
with a very particular regard, 
S I R> 
Tour mojl humble , 
and moft obedient Servant , 
A. De Moivra 
A port method of calculating the value of 
annuities on lives , from tables of obfer-> 
vations . 
A LTHO’ it has been an eftabiifhed cuftom, in 
the payment of annuities on lives, that the 
laft rent is loft to the heirs of the late pofleftor of an 
annuity, if the perfon happens to die before the 
expiration of the term agreed on for payment, 
whether yearly, half-yearly, or quarterly : neverthe* 
lefs, in this freatife 1 have fuppos’d, that fuch a part 
of the rent fhould be paid to the heirs of the late 
pofteflor, as may be exadly proportion’d to the time 
elaps'd between that of the laft payment, and the 
very 
