C 333 ] 
XLIII. Ohfervatlons of the T^ranft of W 
over the Sun, contamed in a Letter to the 
Reverend Nevil Mafkelyne, jdflronomer 
Royal ^ fro?n Dr. Alexander Wilfon, Pro- 
Read Dec. SEND you no.w the particulars of 
1769. obfervation of the tranht of Venus,, 
together with the obfervations of thofe who adted in 
concert with me. I chofe for the place of my ob- 
fervations a houfe at fome diftance from our obfer- 
vatory, but in fight of it, and more free from the 
fmoke of the town; where I had two gentlemen to 
attend the clock, and mark the times., 1 carried with, 
me tworefledors of Mr. Short’s, which are defcribed. 
below. Three other inffruments were made ufe of at 
the obfervatcry; the firfl was an achromatic tube of 
Dollond’s, 29 inch focus, by which an image of the Sun 
was formed, of about fix inches diameter, on a board 
covered with paper. The telefcope being mounted, 
upon a frame, by which it could be turned about as 
the Sun moved, and the room properly darkened. 
This infl:ru.ment was managed by Dr. Williamfon 
r • 
Gollcge,,GIafgovv, Sept. 9^ 1769. 
S I R , 
( 
and* 
