[ 305 ] 
night. When I faw this comet again on the ift of 
April, I could very plainly difcern its tail, but could 
not afcertain its length, becaufe of the morning twi- 
light which was then beginning, and Toon increafed 
much ; it filled the field of the telefcope, and muft 
have extended far beyond. According to what I 
have obferved, the tail of the comet muft have fpread 
to more than 25 degrees. The nucleus was confi- 
derable, but not well terminated, and it apparently 
exceeded the fize of ftars of the firft magnitude. It 
was of a pale whitifh colour, not unlike that of Ve- 
nus. The nebulofity which furrounded the nucleus, 
and went on lefteni ng, ftiewed reddifh colours, and 
thefe colours grew more vivid towards the brighteft 
parts of the tail. The morning twilight, which in- 
creafed apace, foon put an end to thefe appearances, 
and afterwards made the comet itfelf difappear j 
however, I had been able to perceive it with the 
naked eye when it was fomewhat difengaged from 
the vapours of the horizon. In this fhort interval, 
I had but juft time to obferve the flaape of the comet 
with the telefcope, and to compare the nucleus with 
a ftar which I have fince found to be the 30th of 
Aquarius, according to Flamftead’s catalogue, where 
it is fet down as of the 6th magnitude. The differ- 
ence of declination between the comet and this ftar 
was only eftimated. The true time of this obferva- 
tion, which will be found in the fecond table, has 
been concluded only by means of a minute watch, 
which had been fet to the true time in the evening by 
the clock of the marine Ohfervatory. This was 
likewife the cafe with refpetft to the obfervations 
made during the month of April, in the turret of 
VoL. LV. R r the 
