[ 29 + ] 
Received January 31, 17^5.' 
XXXIII, Memoir y containing ' the Hijlory 
of the Return of the famous Comet of 
1682, with Obfervations. of the fafne, 
made at Paris, at the. Marine Obferva- 
tory, in January, February, March, April, 
May, and the Beginning of June, 1759, 
By Mr. Meflier, AJironomer, Keeper of the 
Journals, Plans, and Maps belonging to the 
Marine of France, Fellow of the^ Royal 
Society in London, and Member of the 
Society of Sciences in Holland ; tranfated 
from the French by Matthew Maty, 
M,D. Sec.R,S. 
65"’ T X the predidions of the heavenly phas- 
‘ X nomena, which depend on the mo- 
tion of the ftars, two things are to be confidered, 
viz. the time and place. As to the time, when the 
velocity and diredion of the ftars in their motions 
both apparent and real are known, the time of their 
different appulfes and afpeds may always be fore- 
told, and the accuracy of the calculations depends 
on the exadnefs with which their velocity and their 
feveral inequalities are afcertained. Now it is well 
known that all the former uncertainty, as to the exad 
time of the return of the comet foretold by Dr. 
Halley, was owing to the variations it muft have un- 
dergone from its leveral fituations and approximations 
to the planets in its progrcfs thro’ the folar fyftem. 
Dr. 
