( 3°4 ) 
ftronomers who have Inftruments nice enough, and fuf- 
ficierit Skill in the Management of them, to take Angles 
to 3 or 4 Seconds of a Degree, will obferve what I have 
been mentioning in total and partial Eclipfes of the 
Moon ; by fuch Obfervations they will eafily convince 
.us, that the Figure of the Earth is fuch as Monf. Caf 
fini fuppofes it, or convince him that he lias been mi- 
Itaken. 
The Semi-diameter of the Earth's Shadow , when 
the Earth is in Perihelio, and the Moon in Apogaso 
is 38', or 1280'', without conf dering the Encreafe 
of the Shadow , on account of the At mo/p here of the 
Earth , which wou'd make it 39' or 2340" (< allowing 
one Second for a Mile ; ) and the Semi-diameter of the 
Shadow^ when the Earth is in Aphelio, and the Moon 
in Perig^o is 46^ 20", or 2780", which encreafed 
on account of the Atmofphere of the Earthy will bring 
it to 47', 20" 0^2 840". Now if the Proportion of 95 
to 96 be taken in both Cafes you will have thefe Analo - 
*■". ; S# ; tl$ .8 } * 
— 2340^ = 24^6 will be the ‘Difference of the 
Semi-diameter Sy when the Se&ion of the Shadow is the 
leafy and 2869 /7 ,8 — 284c/' = 29", 8 will be the 
Difference of Semi- diameter s y when the Section of the 
Shadow is the great efl ; the Sum of thofe Differences 
29 '/,8 halve d y will give the Difference, w hen 
the Settion of the Shadow is at a Medium = 27 ' ',4 j 
from which if we take 2 ",4 becaufe in Fig.. 7. C c is 
a little lefs than C P, and in Fig. 6. L C is fomething 
greater than AL C, we ffall have C c in Fig. 7. to 
compare with L C in Fig. 6. which will exceed it by 
25 ", if Monf Caflini’j Figure of the Earth be the 
true one . 
II. A 
