249 



would hardly account for. I repeated the examination in the evening, 

 when the thermometer was 45°'4, and the hygrometer 790. I now 

 found that the focus required lengthening ; but the vision was at its 

 best, and the colours had almost vanished, though a foggy spectrum 

 was perceptible at times. High powers, of course, did not agree with 

 so near an object ; but they were used without greatly distorting the 

 image. 



Thursday, Feb. 28, 1833. — The weather was very fine from 10 to 

 12 p.m., though the wind blew occasionally in hard squalls from the 

 S.W. The instrument appeared but little affected, and yet the ob- 

 servations were rendered unsatisfactory by the frequency of these 

 gusts. At 1 1 the thermometer was 38°*4, the barometer 29'45, and 

 the hygrometer 723. 



1. a Ononis. — Saw 8 of the 10 stars which compose this cluster, 

 but not sharp. The situation was unfavourable, it being two hours 

 and a half off the meridian, and the S.W. quarter of the heavens was 

 hazy. The power used was 250. 



2. £ Orionis. — This, of course, was very plainly seen ; but I fished 

 it up for its definition. The large star had a formidable nimbus, yet 

 it did not prevent the increase of dark vacancy on raising the magni- 

 fying powers. There was much less loose light than I expected, and 

 the small star was palpably of a pale-blue tint. 



3. Rigel.— This star was now too far in the S.W. to be made much 

 of: it was tremulous, and greatly irradiated under power 250. The 

 companion was not visible, and there were two troublesome spectra. 



4. Saturn. — The body of the planet bore magnifying powers, and 

 showed the thin silver line of ring which now appears, without distor- 

 tion, but certainly without sharp definition. 1 could only perceive 

 two of the satellites, while with the flint-glass refractor 1 saw three. 

 The whole aperture was too much for the instrument, and it was 

 therefore cut off to six inches. 



5. As the north was now the clearestpart of the heavens, at about 

 1 1 o'clock the telescope was turned to that direction. The pole-star 

 and its companion were seen very distinctly, even under the lowest 

 power. This, of course, I expected ; but 1 found that it was also 

 viewed on both sides of the object-glass, with much less colour than 

 the other tests I had been looking at. 



Monday, March 4, 1833. — This was the best night I had yet had, 

 and it continued very fair till nearly midnight. I was somewhat 

 troubled with dew, but the instrument was free from tremors, and 

 worked as well as its temporary mounting could admit of. The tem- 

 perature stood thus : 



8 o'clock. 10 o'clock. Midnight. 



Thermometer 45°'5 43°*6 40°'5 



Barometer 29*85 29*86 29*89 



Hygrometer s 740 737 728 



1 . Pdgeh — This star was greatly discoloured at the edges of the 

 field, and was accompanied by a singular spectrum, which was not 

 destroyed by being brought into the centre. I caught the companion 



