SECOND COMET OF 1822, MADE AT RIO DE JANEIRO. 
7 
By M. Hulingenstein’s computation 
from observations in Europe. 
By the computations from Captain 
Robertson’s observations 
at Rio de Janeiro. 
Time of perihelion passage, July 16.03925 July 15.651 
Longitude of the perihelion . . 219 53 48 220 19 49 
Inclination of the orbit . . . 37 43 4 3536 0 
Longitude of the ascending node 97 51 23 98 14 47 
Logarithm of perihelion distance 9.92/43 9.928/9 
“ Perhaps more correct elements might be obtained from a comparison of all 
the observations, European as well as South American, were it deemed of 
sufficient importance to undergo the requisite labour. But without entering 
into such an investigation, enough has been already stated to show that the 
instruments and other means in the possession of every naval officer, are suffi- 
cient to enable him to determine, with considerable accuracy, the orbit of any 
comet which is not too faint for being observed with the usual reflecting in- 
struments used at sea.” 
Before concluding this communication, it may not be improper to mention 
that about the same time that we were making the observations above detailed, 
on the ‘‘second comet of 1822,” we were fortunate enough to see the cele- 
brated comet of Encke, but it had not sufficient light to enable us to observe 
it in the same manner that we did the other. We were therefore obliged to 
content ourselves with observing it through an ordinary telescope. But, as 
it does not appear that on this return of Encke’s comet to the neighbourhood 
of the earth, it was seen in any other part of the world, except at Paramatta, 
the following notes of what we saw of it at Rio de Janeiro, may not be altoge- 
ther uninteresting, though probably of little or no value to astronomers. 
Memorandum of Encke’s comet seen at Rio de Janeiro in 1822. 
June 7th. At 6 h 30 in p.m. Observed the comet calculated by Professor 
Encke, in the constellation Gemini. It was only seen through a telescope, and 
appeared like a faint nebula of a round form. There were two stars of the 5th 
Mean Solar Time at Marseilles. 
Mean Solar Time at Greenwich. 
