J. Lawrence Smith on Meteorites. 339 
which the bodies started (stones with a specific gravity of about 
3°00) must have exceeded 2000 feet a second to permit of an ab- 
sorbed velocity of 1250 feet through the denser portions of our 
atmosphere. Now suppose the force of the extinct volcanoes of 
the moon to have equalled that of AStna, the force would have 
n more than sufficient to have projected masses of matter at a 
velocity exceeding 8000 feet a second ; for, the resistance to be 
overcome by the projectile force, is the attractive force of the 
moon, which is from 5 to 6 times less than that of the earth, so 
that the same projectile force in the two bodies would produce 
vastly greater velocities on the moon than on the earth, discard- 
ing of course atmospheric resistance of which there is none in 
the moon.* 
But doubtless, were the truth of the matter known, the pro- 
jectile force of lunar volcanoes far exceeded that of any terres- 
trial voleanoes extinct or recent, and this we infer from the enor- 
Mous craters of elevation to be seen upon its surface, and their 
gteat elevation above the general surface of the moon, with their 
borders thousands of feet above their centre; all of which, point 
to the immense internal force required to elevate the melted lava 
that must have at one time poured from their sides. I know that 
as 
mulate. Although his hypothesis is ingeviously sustained, still, 
Until stronger proof is urged, we are justified I think in asuming 
the contrary to be true, for we must not measure the convulsive 
throes of nature at all periods by what our limited experience 
has enabled us to witness. pad 
As regards the existence of volcanic action in the moon with- 
out air or water, I have nothing at present to do, particularly as 
those who have studied volcanic action concede that neither of 
these agents is absolutely required to produce it; moreover, t 
Surface of the moon is the strongest evidence we have in favor 
masses Cé 
hot smaller bodies, either planets or satellites, as they pass by the 
earth and through our atmosphete, have portions detached by the 
those bodies is proved. Are we to suppose that each meteor- 
le falling to ee earth is thrown off from a different sphere 
*it gti hy same force ‘to produce an initial velocity of 
8000 higganec ala d earth; and the difference of rate at the end of the first 
f/ 
