•VOL. XII.] PHILOSOPHICAL TRANSACTIONS. 3^3 



decreasing more and more, as far as could be known without a calculation.-^ 

 May 8, from one o'clock in the morning it was sought for in vain with the 

 naked eye, but was discovered with the ] 2-foot telescope, having still a tail, 

 though very short, extending a little to the left hand from the vertical circle. 

 As near as could be guessed, it was in 20° of y , at the distance of 15° from 

 the sun, which was then in 1 9° of y ; the comet was then nearly in a line with 

 the right shoulder of Perseus, and Algol of Medusa, its diameter being hardly 

 equal to the half of Jupiter's. It was still conspicuous enough by the tube, so 

 that at 3^ 45"" we could distinctly perceive it, at near 9° altitude; whence it may 

 be collected that the arch of vision was scarcely then 5°; for the sun was hardly 

 5° below the horizon, and all the stars had disappeared, excepting the planet 

 Jupiter only; and the sun rose at 4*^ 6"*. — May 8, in the evening, the comet 

 could no longer be seen, either with the naked eye or with any telescope, nor 

 yet on any day afterwards. 



Mr. Flamsteed^s Account of his Observations of the late Comet from Greenwich ^ 



May 18, 1677. N° 135, p. 873. 



The first certain notice I had of the comet was on April 21, I waited the 

 rising of it; but immediately after midnight the heavens were overspread with 

 clouds, and continued so till sun-rise next morning, preventing me of my de- 

 sires. The next night, April 22, I again waited for its rising, the heavens be- 

 ing now exceedingly serene and clear, at about 2 o'clock after the midnight 

 following, I saw the tail raised almost perpendicular to the horizon ; soon after 

 the head appeared through a thin vapour, from which the tail pointed, as near 

 as I could guess, on the star in the knee of Cassiopea, its length being about 6 

 degrees, and breadth at the top about 7 or 8 minutes. Viewing the head with 

 a telescope of 16 feet, I found it was not perfectly round, but indented, and 

 not near 1 minute diameter. Afterwards I hasted to measure its distances from 

 several fixed stars, which were as follow: April 22. 



14h 44m Q% ii-g j-jead and the foot of Androm. Alam 11° 26' 0" 



A"] 15.. that distance repeated 11 26 50 



55 3. . its head from Capella 31 1 15 



59 10. . the same repeated 31 1 24 



15 12 2. . its head from Algol in Medusa's 8 16 54 



21 22 Mirach I9 35 O 



27 54 Almech again 11 33 30 



15 36 20 Capella again 30 59 45 



At 15^ 21-I-" p.m. the height of the comet was about 5-^°; therefore the 



VOL. II. 3 £ 



