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XXXI. A Letter from the Prince de Croy 
to the Earl of Morton, P ref dent of the 
R. S. containing the Obfervations of the 
Eclipfes of the Sun of the 16 th of Augufl 
1765, and of the $th of Augufl: 1766, 
made at Calais, together with fame Remarks 
on the firft of thefe Eclipfes : Tranfated 
from the French, by Mathew Maty, M. D. 
Sec . R. S. 
Calais, Augufl 9, 1766. 
My Lord, 
Read Nov. 27, y Have the honour to fend your lordfhip, 
J[ according to your defire, the curious 
obfervation, which I made of the eclipfe of laft year; 
and likewife inclofe with it the obfervation we juft 
now have been making, and which, though lets 
curious, (becaufe this part of the moon has neither 
pits nor mountains), confirms the former with regard 
to the height of the cufps, or that fmall elevation 
which is feen againft the fun’s cufps. I do not fend 
the figure of the latter, becaufe it is nearly the fame 
thing, excepting that it was, as you know, towards the 
lower part of the fun. I think I have feen enough 
to conclude, that the atmofphere of the moon extends 
to at leaft double the height of the higheft mountains 
4 in 
