62 Royal Astronomical Society. 



De Vico's Fifth Comet (July 29, 1846). 



Tliis comet was also detected bj' Mr. Hind, at the South Villa 

 Observatory, on the night of July 29, 1846, about 11 o'clock, two 

 hours after its first discovery by De Vice. 



" The following positions are the results of instrumental compa- 

 risons at South \'illa Observatory with known stars, not far distant 

 from the comet ; but owing to the extreme faintness of this object, 

 the observations of August 4-15 inclusive, are very uncertain : — 



Greenwich M.T. B.A. Dee. 



h m s OIK o I II 



July 29 12 6 6 48 53 47 +60 37 2 



' 30 10 17 35 48 5 34 60 42 33 



31 9 56 19 47 12 6 60 48 10 



Aug. 4 11 11 21 43 11 19 61 8 14 



13 9 21 21 32 4 61 15 8 



14 9 50 23 30 35 67 61 11 5 



15 12 56 27 28 55 22 61 5 10 

 21 9 46 27 19 39 27 +60 2 8 



" On July 29 and 30 we obtained some micrometrical measures 

 with two small stars. On the 29th, at 13^ 25" 25* Greenwich mean 

 time, the comet followed a star of 8'9 magnitude, 2"" r2*-33, and 

 ■was south of it 16' 17 '''8. This star is found in Argelander's Zones ; 

 and the apparent place for July 29, as given in Professor Schu- 

 macher's Comet Circular, was 



R.A. 3^ 13" IP 86 Dec. +60° 53' 47"0, 



whence the comet's place was 



R.A. 3" 15"" 24=- 19 Dec. +60° 37' 29"-2. 



" On July 30, at 11^ 23"^ 13* mean time, the comet followed a 

 9th magnitude star 1"" 25*-07, and was south of it 45"-04 ; but we 

 have not yet identified this star in any of our catalogues. On this 

 night, with great attention, and an exact knowledge of the position, 

 the comet was just perceptible in the comet-searcher." 



Elements o/De Vico's Fifth Comet, by Mr. A. Graham of Markree 

 Observatory . 

 The observations employed were, one at Mr. Bishop's observa- 

 toiy, July 29 ; that of Paris, on August 18; and another made by 

 Mr. Cooper on August 31 : — 



Perihelion Passage, 1846, May 27'82285, Greenwich Mean Time. 



fl- 82 39 19-7 \ Mean Equinox, 



a 161 18 291 / 1846 0. 



i 57 36 24-2 



Log. q 01382020 



Motion Retrograde. 

 The errors of the elements at the time of the middle observation 

 were in geocentric longitude — 1"'4, and in latitude +4"'l. The 

 corrections for aberration and parallax were deduced from M. 

 Goujon's elements. The constants for August 30th, referred to 

 apparent equinox, are, — 



