404 J. R. Mayer on Celestial Dynamics. 
moon, increases with the tangential velocity of our satellite; the 
mean distance of the earth and the moon, and the time of revo- 
lution of the latter, are consequently augmented. The effect of 
this action, however, is insignificant, and, according to caleula- 
tion, does not amount to more than a fraction of a second in the 
course of centuries. 
IX. The Heat of the Interior of the Earth. 
Without doubt there was once a time when our globe had not 
assumed its present magnitude. According to this, by aid of 
this simple assumption, the origin of our planet may be reduced 
to the union of once separated masses. 
To the mechanical combinations of masses of the second order, 
with masses of the second and third order, &c., the same laws as 
those enunciated for the sun apply. The collision of such 
masses must always generate an amount of heat proportional to 
the squares of their velocities, or to their mechanical effect. _ 
Although we are not in a position to affirm anything certain 
respecting the primordial conditions under which the constituent 
Pp existed, it is nevertheless of the greatest 1n- 
terest to estimate the quantities of heat generated by the col- 
lision and combination of these parts by a standard based on the 
finitely small in comparison with T, and when e=T—a=34T- 
These form the limits of all imaginable ratios of the parts T-« 
Terrestrial heights are of course excluded from the following 
is, 
and amounts 
to 8685 x T 
