54 Mr. Gregory's Account of the Discovery of a Comet, &c . 
of Jupiter place me 3' 47 ", in time, west of Greenwich. My 
latitude, deduced from a great number of observations of the 
sun and stars, in all the various ways of determining the lati- 
tude, with Bird's quadrant, Hadley's quadrant, and two equa- 
torial instruments, is 52 0 54' 37" N. 
It remains that I relate what I saw of the comet's tail. 
At 15 11 astronomical time of the 8th, or three o'clock civil 
time in the morning of the qth, I saw a very faint beam 
of light extending itself from the coma towards the zenith. 
When I brought the coma to the centre of the held of the 
night-glass, which takes in about 7 degrees, it reached to near 
the circumference of the held, consequently it amounted to 
about 3^- degrees. I thought it brighter and longer when I had 
a mere glimpse of the comet in the evening twilight on the 
9th. On the 10th, 11th, and 12th, the tail was rather brighter, 
yet very faint ; not broader than a hnger, nor brighter than 
a beam of light let into an ill darkened room for pris- 
matic experiments. It extended itself beyond the circum- 
ference, when the coma was in the centre of the night-glass, 
perhaps a degree, consequently was 4°^ long; it was inclined 
towards the east, and on the 12th pointed due east at mid- 
night. 
On the 11th, the comet passed the middle wire of the 
transit instrument under the pole, at 8 h 28' o" sidereal time. 
The zenith distance was 56° 2' 15". 
I am, &c. 
EDWARD GREGORY. 
