According to Olbers, it would require to reach the
Earth, setting aside the resistance of the air, an initial velocity of 8292
feet in the second; according to Laplace, 7862; to Biot, 8282; and to
Poisson, 7595. Laplace states that this velocity is only five or six times
as great as that of a cannon ball; but Olbers has shown "that, with such an
initial velocity as 7500 or 8000 feet in a second, meteoric stones would
arrive at the surface of our earth with a velocity of only 35,000 feet (or
1.53 German geographical mile). But the measured velocity of meteoric
stones averages five such miles, or upward of 114,000 feet to a second; and,
consequently, the original velocity of projection from the Moon must be
almost 110,000 feet, and therefore fourteen times greater than Laplace
asserted." (Olbers, in Schum, 'Jahrb.', 1837, p. 52-58; and in Gehler,
'Neues Physik.' 'W??rterbuche', bd. vi., abth.3, s. 2199-2136.) If we
could assume volcanic forces to be still active on the Moon's surface, the
absence of atmospheric resistance would certainly give to their projectile
force an advantage over that of our terrestrial volcanoes; but even in
respect to the measure of the latter force (the projectile force of our own
volcanoes), we have no observations on which any reliance can be placed, and
it has probably been exceedingly overrated.
Pages:
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252