242 History of Astronomy for the Year 1805. 
M. de Flaugergues again saw this beautiful spot in the sun 
in the month of April, and this return gave him the rotation 
of the sun 25 days 16 6’, as I have found by many observa- 
tions. (Aslronomie, art. 3276.) 
M. Piazzi, the celebrated astronomer of Palermo, writes 
me, that he has observed the principal stars in the two sea- 
sons of the year, when the difference of the situation of the 
earth in its orbit ought to produce a difference upon the si- 
tuation of the stars.. People have been disputing for these 
two centuries upon this effect of the movement of the earth, 
which has been called the annual parallax. M. Piazzi found 
it in three months 1:5” for Aldebaran, 3” for Procyon, 4% 
for Sirius, from which it follows that the stars are not di- 
stant, as was thought, more than seven millions of mil- 
lions of leagues; but he propuses to continue and verify 
these important observations. 
One of the most important works of 1805 is that of 
M. Legendre, entitled “ New Methods for the Determina- 
tion of the Orbit of the Comets,—Firmin Didot ;” where 
be has quoted the methods of Lambert, and Insignores Or- 
bite in the memotrs of Berlin for 17715 and he gives a new 
method for determining au orbit by three observations; and 
he has applied at to the comets of 1769 and 1781. He makes 
use of a method he calls that of moindres carrés, which also 
served him to determine the 45th degree of latitude, and he 
ccnclude | from it that the length of the arcs of the meri- 
dian is less proper than that of the pendulum for the deter- 
mination of an universal measure. 
M. Gauss, already known as one of our greatest geome- 
tricians, is occupied in computing the attractions of Jupiter 
upon ihe three new planets; but as there will be several 
hundreds of equations, he proposes to give only the me- 
tLods with which our caleulators will easily determine the 
qnantities of these equations. 
“ Lilienthalische Beobachiungen der neu entdeckten Ceres, 
Pallas, &§ Juno, Von Dr. Johann Hieronymus Sehroter ; 
Gottingen, 1805, pp. 336, Svo. Treuttel; price 15 francs.” 
These are observed diameters, but which appear too great 
; according 
