180 
SECOND REPORT— 1832 . 
Iii the volume for 1821, Poisson has treated the precession of 
the equinoxes by Lagrange’s method of the variation of con¬ 
stants. In the same volume is a paper by Laplace on the effect 
which the sea produces on the earth’s motion round its centre. 
In the volume for 1823, he has shown that, supposing the 
earth’s dimensions to have altered by cooling, the effect on the 
length of the day would not be sensible. In Zach’s Cor- 
respondance , vol. 14, Plana has deduced from Lindenau’s nuta¬ 
tion a value for the moon’s mass, which however does not agree 
with that generally obtained from it. 
In the Conn, des Temps 1821 and 1822, Poisson has treated 
of the libration of the moon. His special object is to determine 
the inequalities in the inclination and node of the moon’s equa¬ 
tor, depending on her secular inequalities. 
I have been obliged almost to confine myself to a bare enu¬ 
meration of the titles and subjects of these works, partly by the 
fear of occupying too much space, and partly because it is im¬ 
possible to give an opinion on the methods and accuracy of 
many, without having worked through every line of the investi¬ 
gations ; a degree of acquaintance with them which, I suppose, 
no person living can pretend to possess. 
1 may mention that treatises, of a more elementary kind than 
the originals, and embracing different parts of the subject of 
this section, have been published in England, France, Italy, 
and Germany. 
X. In the preceding sections I have endeavoured to give 
materials for estimating the steps which Astronomy has made 
in this century, and for understanding its present state, at least 
in all the important parts. But I cannot forget that the Asso¬ 
ciation which I have the honour to address, while it is a Philo¬ 
sophical Association, is also a British Association, and that 
while it is anxious to promote science abstractedly, it is also 
jealous of our national scientific character. I feel therefore 
that my Report would be incomplete if I did not, in some de¬ 
gree, give means for answering the questions, What has En¬ 
gland contributed to the progress of Astronomy ? and, How 
have the knowledge and practice of Astronomy advanced gene¬ 
rally in England ? 
I fear that the answer to the first of these questions will not 
be very satisfactory. While I allow that in some important 
parts of Astronomy we have done much, I cannot conceal that 
in other parts, especially those which cast a lustre on the con¬ 
clusion of the last century, and those which are peculiarly di¬ 
stinctive of the present century, we have done nothing. 
