[ *70 ] 
XXII. Obfervation of the late l^ranfit of 
Venus : In a Letter to James Burrow, 
Efquire^ V, P, R, S, By Mr, James 
Horsfall, F, R S, 
S I R, 
Read June 8, 
1769. 
L ooking upon it as the duty of 
every member of the Royal Society, 
to contribute their mite towards the difcovery of 
fuch an important matter as The dimejijioiis of the filar 
Jyfteniy I therefore take the liberty to communicate to 
you the following obfervations, made upon the late 
tranlit of Venus. 
They were made with a Gregorian telefcope, mag- 
nifying at leaft 100 times. 
The time undermentioned is equal time. 
The rate of going of the two clocks had been cor- 
redlly afcertained by my friend Dr. Bevis, and my- 
felf, by obferving the Sun pafs the meridian for feve- 
ral days preceding the day of the tranlit. 
My fituation was upon a platform laid upon the 
ridges of my own chambers near the Middle Temple 
Hall: confequently, the great volumes of fmoke arifing 
from the houfes to the north-weft were no fmall im- 
pediment to a good obfervation : this was very re- 
markable at the time of internal contadi. The Sun’s 
limb undulated then prodigioully, and there was alfo 
a guft of wind v/hich made the telefcope vibrate, but 
not 
