310 Professor Gautier on the Comet of July 1825. 
220° 21 7 ; so that it will then be situated at the extremity of the 
tail of Hydra. 
It is in the interval between the conjunction and the second 
opposition, that the comet must reappear to us. But it is con- 
ceived, that its distance will then render it less than it has 
hitherto been, and it is probable that it will not be at all visi- 
ble to the naked eye at the period of its reappearance. Its de- 
pression beneath the ecliptic, which will be greater seen from 
the earth than from the sun, on account of the great proximity 
of the latter, will also for some time form an obstacle to its view 
in the north of Europe, as may be judged by the following geo- 
centric positions of the comet, resulting from my calculation. 
1826 1st February, 
Right As- 
cension. 
289 .. 25 
South De- 
clination. 
39.52 
Distance from 
the Sun. 
1.474 
Distance from 
the Earth. 
2.222 
1st March, 
283 .. 21 
40.18 
1.730 
1.971 
1st April, 
264.. 4 
41.1 
2.052 
1.549 
20th April, 
241 .. 28 
37.24 
2.258 
1,392 
After the second opposition, the comet will recede at once from 
the earth and the sun, approaching still nearer the ecliptic, and 
I find that it will attain this latter plane, or will pass its as- 
cending node N 7 , towards the 14th July 1826 ; its right ascen- 
sion being 195° 40 7 , and its south declination 6° 41 7 , which 
place it not far from the sword of the Virgin. Its distance 
from the sun will then be 3.178, and its distance from the earth 
N 7 n' 3.085, or about 106 millions of leagues. This great dis- 
tance from the sun and the earth renders, as is easily seen, the 
visibility of the comet at this period doubtful. It is a matter of 
regret that this is the case, on account of the rigorous determi- 
nation of the orbit that might be obtained in a case when the 
comet has been observed in its two nodes * *. 
I must not omit to remark, in concluding this memoir, that 
the elements on which it rests, result only from a first approxi- 
mation *f*. They are also subject to the conditions of the parabo- 
lic hypothesis, which is always followed, for the sake of greater 
facility, in first calculations of this kind; and it is probable that 
* Mecanique Celeste, t. i. p. 230. 
*j* They represent, however, to about one minute of a degree, M, Biela’s ob« 
servation of the 19th July, and P.lnghirami’s of the 29th. 
