the tables.

The subsequent year I see him associated with Lacaille in observing the
transit of Venus over the sun's disk. It was an extraordinary piece of
good fortune, Gentlemen, at the very commencement of his scientific
life, to witness in succession two of the most interesting 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_.