[ 26 3 
VI. A Letter from the Rev . Nevil Mafke- 
lyne, M. A. F. R. S. to William Watfon, 
M D. F. R. S. 
Prince Henry, St. Helen’s Road, 
SIR, Jan. 17, 176 1. 
Read Jan 22, "W" jsj a letter .which I wrote to you from 
I/Gl ' A this place, the beginning of this week, 
I defired you would, in your anfwer to Abbe De la 
Caille, acquaint him, that I had propofed to the 
Royal Society the obfervations of the moon’s paral- 
lax, before his letter came; and that Dr. Bradley 
was to make obfervations at Greenwich, correfpondent 
to mine at St. Helena ; and that I was drawing up a 
lift of the proper obfervations to be made, and the 
proper ftars with which the moon was to be com- 
pared, which I propofed to tranfmit to the Abbe 
De la Caille, in order that he might attend to the 
fame obfervations, if he thought proper. But as he 
has made out a lift of proper opportunities of ob- 
ferving, I fhall only fet down five obfervations to be 
added thereto, which I beg you will tranfmit to the 
Abbe De la Caille 3 and likewife deliver a copy of the 
fame to Dr. Bradley. 
I alfo defired in my letter, that you would defire 
the Abbe De la Caille, and the other French aftro- 
nomers by him, to attend to the obfervations of the 
eclipfes of Jupiter’s fatellites, efpecially the firft, from 
May 1761 to June 1762, inclufive, in order to fettle 
the difference of longitude between Paris and St. He- 
lena ; which it it came in the name of the Society, 
it would be better 5 and that you would alfo deliver 
it 
