1807.) 
right ascension ; and they were able to 
calculate its elements with greater ac- 
curacy, | 
I have spoken, in my History of Astro- 
nomy for 1805, of the ninety-fifth comet, 
which was discovered by Messrs. Bou- 
vard and Pons on the 20th of October, 
and which was visible till the 6th of No- 
vember. M. Macaroil, of the Isle of 
France, informed us, on the 19th of De- 
cember, that he had observed a comet, 
on the 14th of the same month, towards 
the teet of the Peacock, M. Dupeloux ob- 
served it ou the 13th, 14th, and 15th. 
The nucleus was 1/ in diameter, the atmo- 
sphere 45/; it was seen before the stars of 
the third magnitude, and exhibited a 
much more beautiful appearance than 
when observed at Paris. These observa- 
_ tions, which were made at a time when it 
could not have been seen in Europe, will 
be tonnd very useful in correcting its ele- 
ments. . 
M. Burckhardt gave, in the fourth vo- 
lume of the Mécanique Ceéleste of M. 
Delaplace, an explanation of the singular 
phenomenon of the comet of 1770, which, 
though previously invisible, was rendered 
visible that year by the attraction of Ju- 
piter, but which has also rendered it in- 
visible in future. Vhe comet of 1762, 
according to M, Burckhardt, only agreed 
to 5’, but the correction. of refraction 
went the length of 7’, and he rectified 
the elements in the following manner: 
Nodes Sie teil 189.89) 14" 
Inclination - - Ons Sagsiogy to 
Perihelion - - Bie lta on? 6.0) 
Transit 28th May, 8h. 11’. 
Distance, 1:0090485, 
M. Bessel has made very extensive re- 
searches respecting the comet of 1769; 
he found its period to be about 2100 years, 
a result he drew from the whole of 
Messier’s and Maskelyne’s observations, 
which he has reduced with the most 
scrupulous accuracy. The errors in the 
calculation only extend to 5”, as well 
in right ascension as in declination. The 
great number of these observations, joined 
to their extreme correctness, inclined 
him to think that the result must be 
extremely probable. 
Messrs, Gauss, and Bessel have calcu- 
lated the comet of December 1805, and 
that of 1772, in an ellipsis, and have 
found so many differences that it is dif- 
ficult to suppose it to have been the same 
comet; at least we must suppose it has 
suitered some derangements. 
_M. Gauss calculated that of 1805, in 
the parabola and ellipsis, and found that 
Monrury Mac. No. 161, 
Lalande’s History of Astronomy for 1806. 129 
the whele ellipsis, the great axis of which. 
exceeds 2°82, represents the observations 
better than the parabola. He is of opi- 
nion that a great number of comets may 
perhaps exist, though our observations 
are not sufficient to prove that the orbits 
approach the parabola, and that it is ne- 
cessary to calculate for each the limits 
between which the orbit is contained. 
On the 2ist of May a report was 
spread, that the world would come to. an 
end on the 25th; and the prediction of 
the comet that was to produce this awful 
catastrophe was ascribed to me. I re- 
ceived several letters, informing me that 
different persons were taken ill from ter- 
ror in consequence of this report, and 
that some of them had actually died; on. 
which account a man, who hawked this 
pretended prediction about the streets, 
was arrested, and I found it necessary 
to disavow it in the Journal de Paris. On 
the 25th, however, the occurrence of a 
dreadful storm augmented the general 
terror. Onthe 15th of January, 1798, L 
was under the necessity of making a simi= 
lar disavowal, several persons having be- 
come sick, as on the former occasion! 
In the History of Comets, in the Me-= 
moirs of the French Academy for 1775, 
a singular anecdote occurs, ‘relating to 
two stars, marked A andS. The comet 
had been discovered near to these stars 
on the 8th of August, 1769; and the- 
letters refer to two natural daughters 
of Gount Charolais, Adelaide aad So- 
phia, whom M. Bouret wished to have 
occasion to mention when the King was 
at his house, where M. Messier intended 
to present his chart to his Majesty. 
There is one of these stars in the large 
Atlas of M. Bode, put without any letter 
attached to it. I induced him to insert 
in this Atlas eight hundred stars, which 
M. Messier had occasion to determine, 
and which are scattered through the va- 
rious volumes of the Academy, in which 
are detailed his different observations 
on comets; but several of them have not 
yet been published. 
The Transactions of the Royal So- 
ciety of London, for 1804, contain ex- 
periments upon the measurement of 
small angles, and on the size- of planet 
Harding, by Mr. Herschel; he finds for it 
the fourth of a second, but does not po- 
sitively decide whether or no it is: a reaJ 
diameter. 
M. Pigot gives the changes of the star 
of the fifth magmtude, in Sobieski’s 
Buckler, from 61% to 622 days, which is 
sometimes scarcely visible. He disco- 
vered 
