70 Astronomical Societtf. 



limb from a fixed star, he found from the peculiarities of the cli- 

 mate, to be subject to these inconveniencies : viz. The uncertainty 

 in the amount of atmospherical refractions at moderate altitudes in 

 extreme low temperatures: — The alteration of the index error from 

 a change in figure of the instrument, caused by temperature during 

 an observation, and the painful sensation of burning (denominated 

 long ago b)' Virgil, the scalding cold) on touching intensely cold 

 metal with the naked hand. In addition to which, the condensa- 

 tion of the vapour from the eye, in a thin film of ice on the eye- 

 piece of the telescope, rendering the star and the moon's limb ob- 

 scure: — and further, the absolute necessity of holding the breath 

 during an observation, as well as when reading off the measured 

 arc : — all of which are, evidently, serious obstacles to correct ob- 

 servation. 



There was also read a communication from Dr. Rumker, of Star- 

 gard. Paramatta, to Dr. Gregory, containing an account of some 

 observations made at the observatory there. This paper contains, 

 1st, Observations of the great comet in 1825, from October J 8 to 

 December 20, and the elliptic elements thence deduced, as follows : 



Passage of perihelion Dec. . 10-' 18'' 4-1 ■" 7', M.T.Greenwich. 



Long, of perihelion . . . ?]b° 28' 54" 



of node 215 44 58 



Semiaxis major .... 27*7899 j7 



minor .... 8*227477 



Sidereal revolution . . . 53509"3 days 



Inclination 33° 31' 3": motion retrograde. 



2dly, Observations on the comet in Leo, 1825, from July 9 to 

 15th, and the resulting ;jara6o//c elements, viz. 

 Passage of perihelion May . 30-77-65 

 Long, of perihelion . . . 273° 4' 37" 



of node 200 17 34 



. Log. perihel. dist. . . . 9-9552]55 



Inclination 58° 35' 58" : motion retrograde. 



3dly, Observations of the lunar eclipse. May 21, 1826, at Para- 

 matta. Dr Rimiker observed the immersions and emersions of 

 about 30 spots, as well as the time of the beginning and the end, 

 under very favourable circumstances. The darkness of the moon 

 during its total obscuration was such, that the occultations of stars 

 of the 8th and 9th magnitudes could distinctly be observed. Dr. R. 

 only observed the occultation of a star of the 7th magnitude Im- 

 mersion 12'' 34'" 38' : Emersion 12'" 48'" 41" meantime. The de- 

 clination of this star is 19° 46' S. near X£i, which passed 7' N. of 

 the moon's limb. The star described a very small chord, immerging 

 and emerging repeatedly behind the inequalities of the D 's disk 

 before it finally disappeared. 



Lastly, Observations of Mars, near his opposition, from May 5th 

 to May 12, 1826, and the south polar distances of the planet, and 

 his distances from a^ ^ in JR and declination. 



XIX. In- 



