212 



Observations on Comet II. 



any great distance from the head. The whole head was de- 

 cidedly brighter than the tail, and I noticed a remarkably round 

 effect in its shape, and also that in some way the comet's east- 

 ern side was somewhat better defined than the western. I 

 imagined a sort of curve in the comet's general shape, but the 

 whole object was so faint that I could not define what its form 

 might be. 



I saw it next on the morning of August 20th, at four o'clock, 

 but only to observe it fade in the daylight shortly after the dis- 

 appearance of Eta in Ursa Minor • again, however, in the evening 

 I saw it well on a black sky, its tail now tolerably visible, though 

 short, and through the telescope displaying a streaked and 

 unequal appearance. I thought the head not so much brighter 

 than the tail as it had appeared on the night of the 17th. 



Meanwhile, some friends at Florence had observed it on the 

 16th. Even there, adverse weather had frequently concealed it 

 from view, and when seen on the 16th, the tail was barely per- 

 ceptible. 



Mr. Howlett furnishes me with the 

 annexed sketch of the comet (fig. 3), as 

 observed on the 19th, accompanied by the 

 following note : — " Observe the very strik- 

 ingly partial method of the development 

 of the comet's tail, which was almost ex- 

 clusively confined to the eastward of the 

 imaginary fine joining the nucleus and 

 Zeta Ursa Minoris, towards which I could 

 trace it on the 19th instant, at eleven p.m., 

 for eight degrees. At this time the pre- 

 ceding luminous jet appeared to me to form an angle of about 

 168 degrees with the general direction of the comet's tail." 

 Mr. Howlett also remarks — "What a contrast the appearance 

 and form of the comet presented, as drawn respectively on the 

 15th and 19th instant." 



I should here perhaps explain that my reason for employing 

 Mr. Howlett's drawings in preference to my own (which strongly 

 resemble them), is, that the telescope which he employs, being 

 three and a quarter inches aperture, brings out the delicate de- 

 tails of the comet with more completeness than I can expect from 

 mine, which is an inch less in aperture ; and his plan of draw- 

 ing is likely to ensure much correctness. He does not make his 

 sketches literally at the telescope, being impeded by the well- 

 known obstacle in the way of representing faint objects by 

 night, namely, the difficulty of seeing the object in the greater 

 brightness of the lamp used to throw light on one's drawing. 

 He first obtains a good general idea of the comet by carefully 

 viewing it with an opera-glass or an eye-piece of thirty dia- 



FlGr. 3. 



