392 PHILOSOPHICAL TRANSACTIONS. [aNNO I677. 



left foot of Perseus, above Taurus, to the feet of Gemini, if it so long con- 

 tinue. The descending node may be about 20° of Gemini, by conjecture, 

 where it will pass the ecliptic to the southward, with an inclination of its orbit 

 of near 27^- 



May 2, in the evening, at 8^ 45"^, though no stars appeared in that part of 

 the heavens, and there was a strong twilight, yet I presently found the comet 

 with my optical tube. A little after, its altitude was 3° 30'. On account of 

 the twilight the tail appeared very thin, which was extended between the knees 

 of Cassiopea, but nearer to the left. It went down about 1 that evening, 

 in the north-north-west. 



May 3y in the morning, the comet rose at N. N. E, at 1^ 23*", though we 

 saw the tail a little sooner, viz. at 1^ IS"". It was in 14° of y, nearly in 

 conjunction with the sun, having 17° latitude, and nearly the same distance 

 from the sun. This day the tail was longer, extending near 3 degrees, very 

 bright and well defined. Thus we saw it with the naked eyes at 3*^ 34% 

 and with the telescope at 3^ 40"*, at an altitude of 1 1° 30"*; so that the sun 

 at that time was depressed only 6° below the horizon ; and we had seen it 

 longer, but for some small intervening clouds. Its daily motion seemed to 

 decrease, as far as I could judge by conjecture, without a calculation. For 

 between the 29th and 30th of April it moved near 2° 45'; between April 30 

 and May 1, but 2° 15'; between May 1 and 2, but 1° 55'; and between May 

 2 and 3, only 1° 40'. But this will be seen plainer from the observations them- 

 selves and the calculation. — On May 4, in the evening, the air being very 

 pure at 8^ 53% the comet was seen, but a little obscurer than the former days, 

 and the tail shorter. — On May 5, at 1^ 41"* in the morning, it was seen with 

 the tail directed towards the right knee of Cassiopea, its longitude 17° of 

 Taurus, with l6° north latitude, and at the same distance from the sun. Its 

 proper motion from the 3d to the 5th of May was nearly 2° 40", the latitude 

 decreased, viz. from its beginning near 3°; so that the proper motion of the 

 comet, from April 29 to May 5, was 12°. — May 6, in the morning, its place 

 was in 18° of y , with 15° 30' north latitude, the sun being then in 17° of y ; 

 the daily motion then about 50'. The head at that time seemed thinner and 

 weaker than the tail, as the sun was only about 16-i- degrees distant. — May 6, 

 in the evening, it was seen with the optic tube at 8^ 35"*, with the tail shorter 

 and thinner ; but its situation below, and the twilight strong, the comet could 

 not be seen with the naked eye. 



On May 7, the comet was first seen at 2^ 22"*, at 3° altitude, so that it 

 appeared very thin ; its place was then 19° of y, and 15° north latitude; its 

 distance from the sun l6°, the sun being in 18° of y ; its proper motion 



