C 703 ] 
fuppofed invariable. Thefe, as they are very fmall, 
I have only added in that view, that you, who know 
the bed what degree of precifion may be expedted 
from aftronomical obfervations, may judge whether 
they are worth notice or not. 
1 muft obferve, that fome of the points of thefe 
two treatifes have been confidered by others j and if 
my conclufions any where differ from them, I leave 
it to other geometricians to decide which are right. 
All I (hall fay on that head is, that my refult agrees 
with the computation of the great Sir Ifaac Newton. As 
to the method, I have rather chofen to deduce the pro- 
portions by geometrical reafoning, after the manner of 
Sir Ifaac Newton > which in refearches of this kind 
always appeared to me much more fimple, more ra- 
tional, and more elegant, than the long calculus of 
an intricate analyfis. Befides, if in the application 
there flips any error, it is more eafily difcovered in 
the firfl: method. 
As a lover of the fciences, I fhould be glad to 
contribute to their improvement j but, whether what 
is here offered may be reputed a ftep that way, is 
left intirely to your determination. I am, with the 
greateft relped, 
Reverend Sir, 
Rome, Dec. 3. 
1756. 
Your mod obedient 
humble fervant, 
Charles Walmefley. 
4U 2 
De 
