resting astronomical
events: the first predicted and well established return of a comet; and
one of those partial eclipses of the sun by Venus, that do not recur
till after the lapse of a hundred and ten years, and from which science
has deduced the indirect but exact method, without which we should still
be ignorant of the fact that the sun's mean distance from our earth is
thirty-eight millions of leagues.

I shall have completed the enumeration of Bailly's astronomical labours
performed before he became an academician, when I have added, from
observations of the comet of 1762, the calculation of its parabolic
orbit; the discussion of forty-two observations of the moon by La Hire,
a detailed labour destined to serve as a starting point for any person
occupying himself with the lunar theory; finally, also the reduction of
515 zodiacal stars, observed by Lacaille in 1760 and 1761.

FOOTNOTE:

[6] This long list of supposed difficulties in making an exact
observation is hardly worthy of a zealous astronomer. Our author shows
no enthusiasm for his subject here, and ends by ascribing the whole
jeremiad to Lacaille, a man of very great practical perseverance. It is
to be regretted that Arago never refers to observations of his own, but
constantly quotes from others, nor does he always select the best.
--_Translator's Note_.

BAILLY A MEMBER OF THE ACADEMY OF SCIENCES.--HIS RESEARCHES ON JUPITER'S
SATELLITES.

Bailly was named member of the Academy of Sciences the 29th January,
1763. From that moment his astronomical zeal no longer knew any bounds.
The laborious life of our fellow-academician might, on occasion, be set
up against a line, more fanciful than true, by which an ill-natured poet
stigmatized academical honours. Certainly no one would say of Bailly,
that after his election,

"Il s'endormit et ne fit qu'un somme."

"He fell asleep and made but one nap (or sum)."

On the contrary, we cannot but be surprised at the multitude of literary
and scientific labours that he accomplished in a few years.

Bailly's earliest researches on Jupiter's satellites began in 1763.

The subject was happily chosen. Studying it in all its generalities, he
showed himself both an indefatigable computer, a clear-sighted geometer,
and an industrious and able observer. Bailly's researches on the
satellites of Jupiter, will always be his first and chief claim to
scientific glory. Before him, the Maraldis, the Bradley