334 
_eollected 170 pages of obfervations on the 
new planets, and on other important ob- 
jects. 
M. Schréter has publifhed, with plates, 
a Continuation of his Obfervations on the 
Spots of the Moon, in a large volume, 
40. intitled Selenotopographifthe Frag- 
gente, which will ferve to give a corre& 
idea of the furface of that luminary, and 
the changes which have taken place in it, 
in its atmofphere, and in its mountains. 
The firt part of this work appéared in 
31791, from which I publifhed two ex- 
tracts, which fhew with how much pa- 
ticnce and affiduity this able afronomer 
has examined the furface of the moon. 
‘Thefe new obfervations have been made 
with great care, during the laft eleven 
years, by means of the beft optical inftru- 
ments; and they entitle him to the gra- 
titude of aftronomers, as they will ferve 
as a bafe and term of comparifon in their 
future refearches on the changes of the 
moon, He has obferved mountains 4000 
toifes in height, and has been able to de- 
termine, that the part of the lunar atmo- 
fphere, which is capable of producing 
twilight, is about 300 toifes in height, 
He has aifo feen objeéts which were not 
vifible during his former obfervations, and 
which, at firft fight, he attributed to fome 
changes in the furface of the moon; but, 
he remarks, with the referve of an able 
2ftronomer, that the particular ftate of the 
funar atmofphere may have concealed 
thefe objecis at the time of his firft obfer- 
vations. 
Dr. Henzenburg, of Hamburg, made, 
laft fummer, thirty-one experiments on 
the fall of heavy bodies, from the height 
of 235 feet Paris meafure, and he found 
that bodies do not fall vertically ; there 
are 4 lines of declination towards the 
eaft, and 1.5 line towards the fouth; the 
variations have been found to be a little 
more by M. Guglielmini, at Bologna ; 
but all thefe experiments prove the rota- 
tion of the earth. 
I publifhed in June the two laft vo- 
Jurres of Montucla’s Grand Hiftory of 
Mathematics, the fourth is almoft entirely 
confecrated to the hiftory of aftronomy and 
navigation, which I have continued till 
the time that we became acquainted, 
There has appeared alfo, in two volumes, 
quarto, with plates, a Hiftory of the Mea- 
fure of Time by Means of Clocks, by 
Ferdinand Berthcud, in which will be 
found the principal inventions in this 
branch of mechanifm. The author takes 
novice of all the celebrated clock makers, 
excepting his own nephew, to whoni we 
Hiftory of Aftronomy for the Year 1802. 
[May I, 
are indebted for the beft marine watches, 
which have been manufa&tured fince 1734. 
In conneétion with this fubje&, I would 
obferve, that Mr. Emery, of London, is 
lately dead, and his widow has four time- 
keepers to difpofe of, which will bea pre- 
cious acquifition te the purchafers. 
We have received the feventh and eighth 
volumes of the Tranfaétions of the Royal 
Irith Academy; in the former, Mr. 
Young has examined Sir I. Newton’s fo- 
lution of the problem refpeéting the pre- 
ceffion of the equinoxes. 
In July, my fmallTables of Logarithms 
made their appearance ; they are the moft 
exaét and convenient tables yet publithed. 
The third volume of De Laplace’s Meca- 
nique Célefle was publifhed in December, 
which will make a fort of epoch in phyfi- 
cal aftronomy. In this volume will be 
found a continuation of the important re- 
fearches of this great geometrician, and 
the perturbations of each of the planets 
caufed by the action of all the others; a 
new theory of the moon, which contains, 
among other things, a difeovery of a new 
inequality, the period of which, as Ihave 
before cbferved, is 180 years. 
M. Haffenfratz has pubiifhed his courfe 
De Phyjique Célefte; or, Leffons on the 
Expofition of the Syftem of the World. 
In this work, the author takes no notice 
of my Aftronomy, but he has not failed to 
borrow from it whatever was fuitable to 
his purpofe, which he could not find elfe- 
where; I have difcovered fome errors in 
It. 
The Commiffioners of the Board of 
Longitude have fent to the prefs the obfer- 
vations made during the laft two years 
with the new inftruments of the Obferva- » 
tory, by Mechain and Bouvard, to be 
printed in folio, like thofe made at Green- 
wich, and which are worthy of being fol- 
lowed as a model. 
Laft July, M. de Roffel arrived in Pa- 
ris, with the Jcurnal of Voyages made 
with a view of inquiring after La Péroufe, 
under the command of Captain d’Entre- 
cafteux. La Grandiere has alfo a Journ- 
al cf that Voyage, which has been reftored 
by the Englifh Government, who had it 
in their poffeffion about a year. 
Information has been received from 
Citizen Bernier, who has been to New 
Holland, that Captain Baudin put into 
port only twice in the difiance of 1200 
miles through which he failed on the 
wefterncoaft. He prepared to refume the 
continuation of that expedition north and 
fouth, but I fear the zeal of the aftronomer 
will be countera€ted by the indifference of 
4 ee 
