1806.] 
M. de Zach has continued the menfu- 
ration of his degrees of longitude and la- 
titude from Caffel ‘o Gotha; he hopes 
next year to finith 42 of longitude. 
M. de Zach has made obfervations at 
Hieres, ard found that the height of 
Mount Ventoux is 897 teilfes. He hopes 
to finifh in Provence the celeftial are be- 
tween the mountain of St. Victoire and 
the pillar of Ceite, for the degree of lon- 
gitude meafured in 1739, and of which 
doubts have always been entertained. 
At the ifland of Planier he took obfer- 
vations of the fouthernmo& point of 
France. General Roy had formed fome 
Goubts relative to the longitude of Por- 
guerolle, which M. de Zach has deter- 
mined. * 
In the month of March there appeared 
on the fun a large fpot with two nuclei, 
which I cbierved at 9° north of the folar 
equater; this differs but little from the 
beautiful fpots which enabled me.to de- 
termine the rotation of the fun in the 
Memoirs of the Academy for 1776, and 
which were at from 11° to 12°. "Phis 
feems to confirm the difcovery which [I 
then made, by proving that there are in 
the fun points at which large {pots are 
formed in preference; perhaps they are 
mountains which artraét and retain the 
{coria of this immenfe furnace. The pa- 
rallel which is at 9° fouth of the raeee 
abounds moft in large f{pots. 
Thefe {pots with two nuclei, oHiet 
have appeared at different epochs (Me- 
moirs, 1776, p. 487, and 1778), in my 
opinion overthrow the fyllem of volcanoes 
Rae by Herfchel, 
The beautiful fpot of the month of 
March had its middle at 104° of declin- 
ation., That whofe appearance I calcu- 
Jated eee: 1776, p.496), had from 
11° to 149; but a fpot of one minute 
occupies nearly 4°; therefore the moun- 
tain which T fuppole to have ferved it for 
a foundation or obftacle to ftop and fix it, 
may,. by tak: Dg it at a different point, 
eafily draw it 2° or 3° farther in one ap- 
pearance than in the other. 
M. de Flangergues again. perceived 
this beavtiful {pot in the month of April, 
and this return gave him 252 1:05 6! for 
the rotation of the fun, as I have found 
by a great number of obfrvations. 
M. Piazzi, the celebrated aftronomer of 
Palermo, informs me that he hae obferved 
the principal ftars in the two feafons of 
the year, when the difference in thé fitu- 
ation of the earth in its orbit onght to 
produce a difference in the fi uation of the 
_ Montury Mac, No, 144, 
Hiftory of Aftronomy, oy Lalande. 505 
ftars. This effe&t of the earth’s motion, 
which is called annual parallax, has been. 
a fubject of difpute for two hundred 
years. M. Piazzi found it in three months 
"5 for Aldebaran, 3" for Procyon, 4” 
for Sirius, which proves that the itars are 
not, as has been believed, more than feven 
inlions of leagues diftant from. the earth ; 
but he purpofes to continue and to verify 
thefe important obfervations. 
One of the moft important works pub- 
lithed this year, is that of M. Legendre, 
entitled Nouvelles Methodes pour la De- 
termination del Orbite des Comeétes. At- 
ter having mentoned the methods of 
Lambert, in the Berlin Memoiis for 17713 
ot Lagrange, in the fame volume; of 
Laplace, in the Memoirs of the Academy 
for 1780, he gives a new method for de- 
terminisg an orbit by three obferyvations, 
ard applies it to the comets of 1769 and 
1781. He employs the method which he 
calls minor {quares; which likewife ferves 
to determine the 45th deoree of latitude, 
ard hence he concludes that the length of 
arcs of the meridian 1s iefs proper than 
that of the pendulum to determine an 
univerfal meafure. 
M. Gaufs, already known. as one 3 
our greateft aftronomers, has underteken 
to calculate the attraétions of Jupiter on 
the three new planets; but as there will | 
be feveral hundred equations, he purpofes 
to give only the methods by which our 
calculators may ealily determine the quan- 
tities of thofe equations. 
A. work, entitled Lelexthalifche Beo- 
bachiunger der neu-entdeckten Ceres, Pal- 
les, und Funo; or, Obfervations made at 
Lilicnthal, on the recently difcovered Pla- 
nets Ceres, Pallas, and Juno, by Dr. J. 
H. Schioter, 336 pages, vo. gives the 
obferved diameters, but which appear too 
large according to the memoir of ‘Her- 
fchel. He finds the firft, or Piazzi, 3)°"5, 
if the diftance be taken at ohe; diameter 
587 leaoues: the fecoad, or Ojbers, 4,55 
diameter 760 leagues: the third, or Hard. 
ing, 3, "15 Giameter 516 leagues. 
‘In the Bib/io:b eque Britannique for the 
month of Avguft, is an Ephemeris of the 
three planets ull the month of May, 1806. 
Tie aftronomical medal,. given by La- 
lance, which is adjudged every year about 
the-fpring equinox, was de creed by the 
Inititute fo M. Harding for the ig een 
of his planet. 
The premiem which M. Bode ee been 
direfied te give for the beft memoir on 
aflronomy, has been raifed to 609 francs. 
(To be continued.) 
37 An 
| 
ti 
—- ae 
nen aa ss 
wal pe 
Se eta are 
ee 
— 
