198 Scienlijic Intelligenct. 
. Art, XXXVIL— scientific INTELLIGENCE, 
I, NATURAL PHILOSOPHY, 
ASTRONOMY. 
1 . La Place's Results respecting the Form and Structure of the 
f^arth.’—ha Place has given the following very interesting re- 
sults, as deduced from analysis, and from the experiments made 
with the pendulum in both hemispheres. 
1. That the density of the strata of the terrestrial spheroid 
increases from the surface to the centre.-— That the strata are 
veiy nearly regularly disposed around the centre of gravity of 
the earth. — -3. That the surface of this spheroid, of which the 
sea covers a part, has a figure a little different from what it would 
assume in virtue of the laws of equilibrium, if it became fluid.-.^ 
4. That the depth of the sea is a small fraction of the difference 
of the two axes of the earth. — 5. That the irregularities of the 
earth, and the causes which disturb its surface, have very little 
depth. — 6. That the whole earth has been originally fluid. 
These results (says La Place) of analysis and experiment, 
ought, in my opinion, to be placed among the small number of 
truths which Geology presents^’ 
% On the Lihration ofihtMoon . — Our astronomical readers are 
aware, tliat the moon turns round her owm axis in the same time 
that she performs her mean revolution round the earth ; that 
the inclination of the lunar equator to the ecliptic is constant ; 
and that its descending node coincides with the mean ascending 
node of the moon’s orbit. Lg. Place has sliewn, that these re-^ 
suits are not affected by the secular equations of the moon’s 
mean motion, nor by the secular displacements of the ecliptic. 
M. Poisson has shown, that they are likewise not modified hy 
the secular equation which affects the mean motion of the 
moon’s node, but that they correspond to the mean velocity of 
rotation, and a mean state of the lunar equator. The theory 
indicates, that this velocity, as well as the inclination of the 
equator, and the distance of its node from that of her orbit, are 
subject to periodical inequalities. La Grange has expressed by 
formulae the principal inequalities of the velocity of rotation ; 
and M. Poisson has very recently determined the inequalities of 
the inclination and of the node, The formnlfe to which he 
