(28ers 
[OS 
ANECDOTES OF EMINENT PERSONS, 

ELOGE OF BAILLY, THE CELEBRATED 
ASTRONOMER AND-MAYOR OF PARIS. 
BY JEROME LALANDE. 
EAN Sytvain BarLiy was born 
at Paris, on the 15th of September, 
fion of his family who icllowed the pro- 
feffion of a painter ; and the difeafe which 
proved fatal to his grandfather was oc- 
cafioned by his experiments in ftaining 
marble with fome pigments that he had 
brought with him from China. 
Young Bailly was alfo deftined to. 
painting, and had already made fome 
progrefs in the art, when he fhowed a 
decided inclination for the ftudy of the 
Belles-letires. In this wide field of gene- 
tal literature, poetry was the firft object 
that engaged his attention: he even pro- 
duced fome tragedies which were praifed 
by Lanoué, not however without advifing 
his young friend toattend rather toicience. 
Mademoifelle Lejeuneux the painter, 
an acquaintance of Bailly, was the in- 
timate friend of Lacaille, a circumftance 
which effentially contributed to direct 
his attention to the ftudy of Natural Phi- 
lofophy ; accordingly, in the year 1762, 
he prefented to the academy ‘* Ob{erva- 
tions on the Moon,’ which Lacaille had 
made him draw up with ali the particu- 
larity of detail required by the new ftate 
ef aftronomy, and which were quoted by 
him with approbation, in the fixth volume 
of the Ephemerides. 
He calculated the cfbit of the comet of 
1759; the period of whole return had 
eccupied the attention of aftronomers, 
znd on the 29th of January 1763, he was 
received into the Academy of Sciences. 
In the fame year he publifhed a large 
and ufeful work, the reduction of the 
ebfervations which Lacaille had made in 
2760 and 1761, on 515 zodiacal fiars, 
132 of which.are not to be found in pre- 
ceding catalogues: the remainder are 
contained in Meyer's Zodiac, but their 
politions are laid down with much greater 
exatineis by Lacailles Bailly thus: ren- 
dered an important fervice to aftronomy 
by editing a work, which, on account 
of the death of its author would have re- 
mained ufelefs,. if it had not been for the 
zeal of his pupil. 
Baiily be&an about this period alfo to 
turn his attention to the theory of the #a- 
tellites of Jupiter, the difficulty and im. 
portance of which had already attracted 
the notice of the Academy, who pro- 
pofed it as a prize fubje in April 2764. 
ns x 
_ or mayors of Paris. 
Le Grange, who now ftaod firft among 
the geometricians of Europe, was one of 
the candidates tor the prize. The theory 
of Clairaut. was employed by Bailly in 
: calculating the fame perturbations: the 
1736. His father was the fourth in fuccef- > P 
united efforts of thefe two philofophers 
for the firft time made us acquainted with 
the fingular derangements of thefe little 
planets, by conftructing ‘new tables of . 
them, for all former attempts had been 
merely empirical. 
{In 1766 he publifhed an important 
treatife, with the modeft title of Efjaz fur 
la Théorie des Satellites de Fupiter, (EMlay 
on the Theory of Jupiter’s Satellites) toge- _ 
ther with tables of their movements and 
the hiftory of this branch of aftronomy, 
in 53 pages 4to. The moft ingenious 
memoir which he publifhed, is that for 
1771 on the light of the fatellites. On 
this occafion be availed himfelf of an ex-. 
cellent idea of FFouchy, of covering the 
end of a telefcope with thin pieces of 
bladder till the fatellite could be no 
longer feen, in order by this means to 
meafure the degree of its light. He alfo 
obferved and calculated the changes pro- 
duced by their proximity to Jupiter, and - 
their altitude above the horizon; he af- 
certained their diameters, the duration 
of their feveral immerfions, and invented 
a method of compofing the obfervations 
made with different telefcopes, by which 
he introduced a degree of perfeStion till 
that time unknown in this part of aftro- 
nomy. This learned work immediately 
ranked him among our beft aftronomers, 
and it was at this period that I told him 
that I fhould prefer being the author 
of fuch a work than being the frit on 
the lift uf prefidents of the ftates general 
The intervals of his 
aftronomical Jabours were agreeably oc- 
cupied by general literature. In 1757 he 
was elected member of the Academie 
Frangoife, for his e/ge of Charles V. a 
work which obtained dittinguifhed praife 
from the academy, though the prize was 
adjudged to La Harpe. . 
In 1768 he fent to the Academy of 
Rouen the elage of Corneille, which gained 
the accefit. His eloge of Leibnitz, fent to 
the Academy of Berlin, obtained the 
prize. In 1769 his eloge of Moliere gain- 
ed the accefit at the Academie Francoife ; 
the prize was gained by Chamfort. His 
abilities in this ftyle of writing were ftill 
further rendered confpicuous by the eloges 
of Cook, Lacaille and Greffet ; fo much 
fo, that Buffon and many other meee 
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