Posidonius even ventured to deride the geognostic myth of
the blocks and stones. The Lygian field of stones was, however, very
naturally and well described by the ancients. The district is now known as
'La Crau.' (See Guerin, 'Mesures Barom??triques dans les Alpes, et
M??t??orologie d'Avignon', 1829, chap. xii., p. 115.)
p 116
We can ascertain by measurement the enormous, wonderful, and wholly
planetary velocity of shooting stars, fire-valls and meteoric stones, and we
can gain a knowledge of what is the general and uniform character of the
phenomenon, but not of the genetically cosmical process and the results of
the metamorphoses. If meteoric stones while revolving in space are already
consolidated into dense masses,* less dense, however,
p 117
than the mean density of the earth, they must be very small nuclei, which
surrounded by inflammable vapor or gas, form the innermost part of
fire-balls, from the height and apparent diameter of which we may, in the
case of the largest, estimate that the actual diameter varies from 500 to
about 2800 feet.
[footnote] *The specific weight of a?‘rolites varies from 1.9 (Alais) to 4.3
(Tabor). Their general density may be set down as 3, water being 1. As to
what has been said in the text of the actual diameters of fire-balls, we
must remark, that the numbers have been taken from the few measurements that
can be relied upon as correct.
Pages:
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238