LISLE. 
had now acquired, that fcarcely any book of hiftory or 
travels was publifhed, which the authors were not de- 
firous of embellilhing with his maps. And this reputa¬ 
tion was not confined to France, but extended through¬ 
out Europe. Hence many fovereign princes endeavoured 
to tempt him to enter into their fervice ; but without fuc- 
cefs. Peter the Great, when he was at Paris on his tra¬ 
vels, took an opportunity of vifiting him in a familiar 
manner, to communicate to him fome remarks upon Muf- 
covy ; “ but more efpecially,” fays Fontenelle, “ to learn 
from him, better than he could any where elfe, the extent 
and fituation of his own dominions.” De Lille died by a 
ltroke of apoplexy in 1726, when he was only in the fifty- 
firft year of his age. There are feveral papers by him in 
the Memoirs of the Academy of Sciences ; and a lilt of 
hit productions may be feen in Freret’s Eulogium on him 
in the Mercure for the month of March 1726. 
LI'SLE (Louis de), furnamed de la Croyere, the third 
fon of Claude, was diftinguilhed by his proficiency in af¬ 
tronomical ftudies, which recommended him to a feat in 
the Academy of Sciences. Though he left no works be¬ 
hind him, excepting what he may have contributed to the 
Memoirs of the Paris and Peterlburg academies, he de- 
lerves to be noticed among thole who have rendered fer¬ 
vice to the interefts of fcience, on account of the ha¬ 
zardous journeys and voyages which he undertook to pro¬ 
mote them. In the year 1726, he went to Ruflia with his 
brother Jofeph-Nicholas, the fubjeCt of the next article, 
who was appointed aftronomer to the Academy of Sci¬ 
ences at Peterlburg. From that capital Louis de Lille 
made fcientific excurfions, beyond the utmoft boundaries 
of the immenfe Ruffian empire. He took leveral journeys 
to the coafts of the Icy Sea, to Lapland, and the govern¬ 
ment of Archangel, to determine the fituation of the 
principal places by aftronomical obfervations. For the 
fame purpofe, by order of the court of Rulfia, he after¬ 
wards travel led a great part of Siberia, in company with 
Muller and Gmelin, profelTors of the Peterlburg academy. 
Having quitted his companions in that country, he pro¬ 
ceeded alone to Kamtfchatka, where, in 1741, he em¬ 
barked on-board the veffel commanded by the Ruffian 
captain Alexis Tchirikow, who proceeded with captain 
Beering, to examine the unknown northern coafts of Ame¬ 
rica, and the leas between them and the Afiatic continent. 
But he furvived this voyage a very Ihort time, dying in 
the fame year, after his return to the port of Avatlkha, 
where he commenced the voyage. 
LI'SLE (Joieph-Nicholas de), a very able aftronomer 
and geographer, was brother of the preceding, and born 
at Paris in the year 1688. After having been inftru&ed 
in grammar-learning by his father, lie attended leClures in 
the Mazarin-college, where he went through his rhetori¬ 
cal exercifes in 1706. The total eclipfe of the fun, which 
took place on the twelfth of March in that year, having 
occafioned the difcovery of his genius for mathematical 
purfuits, he was placed under a proper tutor, with whom 
he ftudied the elements of geometry, fortification, and 
mechanics. But, while purfuing thefe fubje&s of ftudy 
and curiofity, he felt an irrefiltible inclination for the fci- 
cnce of aftronomy. Even before he had feen any aftro¬ 
nomical treatife, he had committed to paper his reflections 
on the apparent diameters of the fun, the length of which 
he perceived to vary ; on the eccentricity of its orbit, 
which he thought to be the caufe of that variation ; on 
the method of meafuring ecliples ; and on the interfeftions 
of horary circles which conftitutea dial. This genius for 
invention, combination, and calculation, infpired our 
young mathematician with a tafte for refearch, which 
enabled him to advance rapidly in his acquaintance wjth 
aftronomical fcience, and eafily to become mafter of the 
gnomonics of M. de la Hire, which molt beginners find 
io difficult. 
In the year 1707, M. de Lille was offered the place of 
an engineer at Martinico. This offer proved the occalion 
of his learning the art of drawing, the knowledge of 
which afterwards proved highly uleful in his geographi- 
Vol. XII. No. 871, 
759 
cal labours, by enabling him to defigumaps with as much 
neatnefs as correClnefs. Of this art likewifehe knew how 
to avail himfelf in his aftronomical fttidies, fo as to draw 
figures with the utmoft precifion, better adapted to abridge 
calculations and to Amplify the working of problems, 
than any which had before appeared. In the year 1708, 
he had already begun to engage in aftronomical calcula¬ 
tions with M. Lieutaud, and to frequent the obfervatory 
of Calfini the younger, who was then employed on his ta¬ 
bles of the fun and moon. In 1709, he obtained leave to 
occupy the cupola of the Luxemburg palace facing the 
ftreet de Tournon ; and, lince he was now in polfelfion of 
an obfervatory, he flattered himfelf with the hope that he 
ftiould be able to coriftruCt the neceffary inllruments by 
his own ingenuity. He fucceeded fo far as to make a 
wooden quadrant, which he divided with great care, and 
found to anfwer his purpofe in his early obfervations. At 
the fame time he calculated, for M. Calfini, a table of the 
right afcenfions and declinations in degrees, minutes, and 
feconds, adapted to all the degrees of longitude and lati¬ 
tude of the planets, and the obliquity of the ecliptic £ 
which M. Calfini made ufe of in predicting the occuita- 
tions of the ftars by the moon, in the Connoiflance des 
Temps. 
In the year 1710, Caffini having communicated to our 
young aftronomer his method of reprefenting an eclipfe 
of the fun, by the projection of a terreltrial parallel on a 
plane ; de Lille immediately conceived an idea of render¬ 
ing it applicable to every part of the earth, by means of 
a globe, mounted and prepared for that purpofe. The 
aftronomers, to whom he gave fome intimation of his 
project, confidered it to be impracticable ; but, when his 
machine was completed, they beltowed high applaufe on 
his invention ; and Calfini, who was then blind, by exa¬ 
mining it with his hands, fully comprehended its utiiity. 
The model, in relief, was depoiited in the royal obferva¬ 
tory. The firft remarkable obfervation of M. de Lifle was 
that of the moon on the 23d of January, 1712 ; after 
which his labours were for fome time interrupted by ill- 
health. The circumftances of his father’s numerous family 
made it now neceffary that he fhould endeavour to procure 
for himlelf the means of fupport; and, in doing fo, he 
found himfelf obliged to render his aftronomical fkill fub- 
fervient to the reveries of judicial aftroiogy. At that time 
the count de Boulainvilliers was famous at court for his 
horofeopes and altrological predictions; and he engaged 
young de Lifle to employ himfelf on calculations relative 
to thefe predictions. For thefe fervices our aftronomer 
was remunerated by pecuniary prefents from the regent, 
the marlhal de Noailles, and other courtiers; and he had 
alfo the grant of a penfion of fix hundred livres in the 
year 1715. It was on this occafion that he calculated ta¬ 
bles of the moon according to the theory of Newton, be¬ 
fore Halley had communicated to him thofe which he 
printed 5111719, or Flamfteed had given the tables which 
M. Lemonnier printed in 1746. In the year 1714, M. de 
Lifle had the honour of being eleCted to a feat in the 
Academy of Sciences, which gave new' energy to his ex¬ 
ertions ; and the Memoirs of this body were in a fhort 
time enriched with his valuable reflections and differta- 
tions. 
Being deprived of his obfervatory at the Luxemburg 
during the following year, he continued his obferva¬ 
tions at the hotel de Taranne, and afterwards at the royal 
obfervatory during the abfence of the aftronomers, who 
were engaged in prolonging the meridian of Paris towards 
the north. The necelfity that he was under of frequently 
changing his obfervatory and his inftruments, was no lit¬ 
tle obltacie to the progrefs of a young obferver; and it 
was not before the year 1721 that he was able to procure 
a quadrant of forty-three inches radius, with which he 
afterwards made a great number of obfervations. Among 
the Memoirs of the Academy of Sciences for the year 
1715, may he found his obfervations on the atmofphere 
of tiie moon, and on the luminous rings vifible during 
eclipfes. In the year 1713, he had obferved the fpots in 
9 P the 
