, younger brother of the preceding, was born at Paris April 4, 1688, and at first educated under his
, younger brother of the
preceding, was born at Paris April 4, 1688, and at first
educated under his paternal roof. He then pursued his
studies at the Mazarine-college, where the eclipse of the sun
in 1706 seems to have directed his attention to astronomy,
for which he soon displayed so much genius, as to be admitted into the academy of sciences, to the memoirs of
which he contributed many valuable papers. In 1715 he
calculated the tables of the moon according to the theory
of sir Isaac Newton. He also, in the course of his pursuits, made many observations on the spots of the sun, and
from them formed a theory to determine the sun’s rotation
on his axis. In 1720 he delivered a proposal to the academy for ascertaining in France the figure of the earth, and
some years afterwards this was carried into execution. In
1724 he paid a visit to England, where he became acquainted with Newton and Halley, who shewed him every
mark of respect, and Halley in particular highly gratified
him by a present of a copy of his astronomical tables of
the sun, moon, and planets, which he had printed in
1719, but which were not published for many years after.
In. 1726 he was appointed astronomer royal in the imperial
academy of sciences at Petersburg, where for twenty- one
years he resided in the observatory-house built by Peter
the Great, incessantly occupied in the improvement of
astronomy and geography. During this period he published “Memoirs illustrative of the History of Astronomy,
”
2 vols. 4to; and an atlas of Russia, first published in the
Russian language, and afterwards in Latin. He constructed
also a thermometer, differently graduated from those in
use, the degrees beginning at the heat of boiling water,
and thence increasing to 150, which was the freezing point.
In 1747, after much ill-treatment on the part of the Russian government, he obtained his dismission, and arrived
in Paris in September of the same year. He was then appointed professor of the mathematics at the college royal,
in which situation he lived to render the greatest service to
the interests of science, by training up some learned pupils, among whom was the celebrated M. de la Lande. In
1743, his pupil, M. Monnier, took a voyage to Scotland to
observe an annular eclipse of the sun, and on this subject
De Lisle published a large advertisement, which was reckoned a complete treatise on annular eclipses. He afterwards entered more fully on the consideration of the theory
of eclipses, and he communicated a part of his researches
on the subject to the academy in 1749. He was so expert
in calculations, that he made many founded on the observations of Greenwich, Berlin, Scotland, and Sweden. In
1750 and 1753 he published “New charts of the Discoveries of admiral de Fonte, or Fuente, made in 1640, and
those of other navigators, Spanish, Portuguese, English,
Dutch, French, and Russian, in the Northern seas, with,
explications.
” In Mercure,
” for July of that year.
He was afterwards assiduously engaged on the transit of
Venus, expected in 1761, in order to correct the error of
Halley, and thus prevent persons from undertaking long
voyages unnecessarily for the sake of observing it. He
had, some years previously to this, been appointed astronomical geographer to the marine, and his business was to
collect and arrange the plans and journals of naval captains,
and to extract from them whatever might be found beneficial to the king’s service in this department. His majesty
now purchased, with a pension- for life, all M. de Lisle’s
rich astronomical and geographical collections, which were
added to the Mss. in the depot. In 1758, JDeginning to
decline, he withdrew as much as he could from public life,
leaving the care of his observations to M. Messier, while
M. de la Lamle was appointed his coadjutor at the college
royal. He went to reside at the abbey of St. Genevieve,
where he spent his time partly in devotional exercises, and
partly in study, devoting the greatest part of his income
to- acts of benevolence and charity. He died on the 11th
of July 1768, in the eighty-first year of his age. As a
man of science his merits are very great, and in private
life he was distinguished by unaffected piety, pure morals,
undeviating integrity, and most amiable manners.