160 



hazy 



8 27 58 



5 53 28" 



110 



do. 



8 27 59 



5 53 29 



80 



do. 



8 28 12 



5 53 42 



80 



do. 



8 28 05 



5 53 35 



1832.] Eclipses of Jupiter's Satellites. 505 



marked : still the observation was under unfavourable circumstances, 

 and affords results applicable only to such. To save trouble all the obser- 

 vations have been reduced to the same meridian, namely, that of the 

 Ochterlony monument, by applying — 2 sec. to those of the Surveyor 

 Genl. Capt. Ross, and Mr. Barrow, and -h 1 sec. to those of Mr. Gray: 

 during the remainder of the month other observations were made in a 

 similar manner : — they have been reduced to the same meridian, and 

 the telescopes used are distinguished by letters of reference. P. 



l§th October. — Emersion of Jupiter's first satellite, Calcutta. 

 Observer. Telescope. Aperture. Power. Note. Obs. Me. Ti. Longitude. 



Prinsep, a. ten-foot reflector 9 in. 



Pemberton, b. four-foot achrom. 3.7 



Gray, c. 42 in. achromatic, 2.7 



Logan, c. 42 in. ditto, .... 2.7 



Ross, c. 42 in. ditto, 2.7 80 dull glass 8 28 37 5 54 07 



26th October. — Emersion of I Sat. observed in Calcutta. 



At the Surv. Gen.'s, Wilcox, c. [42. in. 2.7 ap. 80 p.] 10 23 15 5 53 05 



Waugh, c. 10 23 41 5 53 31 



Logan, c. 10 23 25 5 53 15 



At Mr. Calder's, Pemberton, b. [4 ft. achr.] 10 24 09 



Prinsep, a. [10 ft. ref.] 10 24 09. 



At Mr. Gray's, Gray, c. 10 24 01 5 53 51 



drifting clouds were passing the planet from the N. W. at the moment, and when 



the satellite was first seen, it had evidently been some seconds out of eclipse. 



There were eight seconds between the two last observations, which was about 



the time occupied by the cloud in passing from one station to the other. The sky 



was cloudless in Chowringhee. 



h. m. s. h. m. s. 

 3rd Nov. — Emersion of II Sat. observed by Mr. Gray, tel. ' c. 7 52 8 5 53 20 

 4th Nov. — Emersion of I Sat. observed ; 



By Captain Ross, with telescope c. 42 inches. ;6 48 38 5 53 46 



By Lieut. Lloyd, with the telescope used by Captain Ross 

 on the 19th ultimo, the object glass tarnished, the emersion 

 was not visible until 14 seconds after. The evening was very 

 favorable and clear. 



By Mr. Logan, at the Sur. Gl. office. c. 6 48 12 5 53 20 



10th Nov.— Calcutta, very clear sky ; moonlight, (16th day.) 

 Emersion of III. Sat. Gray, telescope 



Gordon, d. 60 in. 3.7 ap. 110 

 Logan, d. 60 in. 3.7 ap. 99 

 Em. II. Sat. Prinsep, 10 feet Refl. 

 Gordon, 

 Gray, 

 Logan, 



2 s 2 



53 59 



c. 



very good 



7 54 5 



5 53 33 



p. 



doubtful, 



7 54 56 



5 54 34 



p- 



moonlight, 



7 53 41 



5 53 19 



a. 



bad focus, 



10 27 17 



5 52 53 



b. 



good, 



10 27 27 



5 53 03 



c. 



good, 



10 27 27 



5 53 03 



c. 





10 27 32 



5 53 08 



