%807.] 
For the Monthly Magazine. 
WISTORY of asTRONOMY for 1806, By 
JEROME DELALANDE. 
(Continued from page 251.) 
WORK on the present surface of 
the earth, or rather impartial ingqui- 
ries respecting the period at which the 
earth assumed its present arrangement, 
founded solely on facts, independent of 
any system or hypothesis, by M. André, 
has lately made its appearance. In it 
every thing is referred to the deluge, but 
it contains) many interesting obser vations, 
which have no connection whatever with 
the peculiar ideas of the author. In the 
Journal des mines, (No. 108, pages 
321 to 377,) are published observations 
upon the barometer, and on the heights 
of mountains, made with incredible labour 
by this intrepid traveller, This collection, 
which must prove so highly interesting to 
individuals engaged in the study of veo- 
logy and meteorology, forms a continua= 
tion to those of Sir G.Shuckburgh, in the 
Philosophical Transactions for 1777; it 
1s much to be wished that such examples 
may be generally imitated. 
M. André, in his geology of the moun- 
tains he visited, informs us that he ev ery 
where found traces of their having at one 
time been overflowed. He does not en- 
deavour to explain the retreat of these 
waters, but I conceive that I myself have 
proved that they are contained in subterra- 
nean cavities immediately underneath the 
superficial crust of our earth. Journal de 
‘Paris, November 8, 1805: Journal des 
Débuts, May, 7, 1807. 
Noé André was born in 1728, and be- 
came a capuchin in 1745. In 1770 he 
had in contemplation to execute a chart 
of Franche Comté; having, however, ac- 
cidentally come to Paris in 1773, he was 
well received by M. Monnier, who lodged 
in the Court of the Capuchins. In 1778 
and 1780 he made some celestial planis- 
pheres, and in 1781 he set out on his tra- 
vels, which he prosecuted six months an- 
nually during the period of six years. 
The valuable collection of observations, 
already mentioned was the fruit of these 
different journeys. 
M. de Lezenne, professor at Lisle, has 
printed an Elementary work on Gnomo- 
nics, in 26 pages, which will be found a 
very useful companion to those astrononu- 
cal works in which this application is not 
sufhciently given in detail. I gave in 
1784 a more extensive ana complete 
Treatise in the Encyclopédie Methodique, 
under the word Dial, vol. I. article Ma- 
thematics. It was my intention to have 
Monrury Mac., No, 163, 
Lalande’s History of Astronomy for 1806. 
323 
introduced it into the fourth volume of my 
Astronomy, which appeared in 1781, but 
the great multiplicity of matter prevented 
me. It has not even been printed sepas 
rately, which has greatly limited its use- 
fulness; it contains fourteen species of 
dials, several of which are not.to be found 
in any other treatise except that of 
Don Bedos, 1778, in 8vo. which is 
the most complete, and extensively 
known of any of which we are yet in 
possession. 
The necessity of procuring good instru- 
ments without the assistance of the Bri- 
tish has determined our government to 
place pupils under the care of our most in- 
telligent artists. 
The exhibition of the productions of 
our artists and manufacturers, which was 
conducted this year under the auspices of 
M, Champagny, minister of the interior, 
discovered a multitude of important ob-- 
jects. M. le Noir, one of our. most 
able engineers, exhibited an azimuth cir- 
cle, an equatorial, and repeating circle, 
a circle of reflection for the navy, a va-= 
riation compass, and an_ inclination 
compass, all of his own manufacture. 
He likewise exhibited an instrument by 
M. Rochon, for reducing distances at 
sea; a level ‘ak a new construction; two 
circles for finding the horizontal and the 
vertical angles; a micrometer, for mea- 
suring the distances of remote objects; 
a smaller and more convenient grapho- 
meter than any yet in use; an armillary 
sphere, which gives both the true and 
mean time; an astronomical ring; and a 
lew compensation pendulum, made with 
glass and copper. 
M. Lerebours also contributed to en- 
rich this exhibition with optical, and M. 
Jeker with nautical, instruments. Several 
fine pieces, both in clock and watch work, 
were likewise exhibited by Messrs. Bre- 
guct, Lepante, Jauvier, Pons, &c.; of 
these a detail has been given in the cata- 
logue of the exhibition, and in the Moni- 
teurs of the 26th of October, and 12th of 
December, 1806. 
I transmitted to Romea circle, made by 
M. Belet, and a pendulum by M. Pons, 
the accuracy of which was much admired 
by the Italian astronomers. 
M. Zeichenbach, at Munich, and Bau- 
mann, at Stutgard, make very fine instru- 
ments. By the repeating circles of the 
last mentioned of these artists, an indivi- 
dual may make observations without the 
help of an assistant, by means of a plumb- 
line place in the inside of a_ hollow cy- 
lindrical axis, according to the mode pros , 
posed by M, Bohnerberger, 
Uu Sextants 
