In fact, it is only during the period of the
full Moon that these streaks are seen at all; as soon as the sun's rays
become oblique, they disappear altogether--a proof that their appearance
is due altogether to peculiar advantages in their surface for the
reflection of light."
"Dear boys, will you allow me to give my little guess on the subject?"
asked Ardan.
His companions were profuse in expressing their desire to hear it.
"Well then," he resumed, "seeing that these bright streaks invariably
start from a certain point to radiate in all directions, why not suppose
them to be streams of lava issuing from the crater and flowing down the
mountain side until they cooled?"
"Such a supposition or something like it has been put forth by
Herschel," replied Barbican; "but your own sense will convince you that
it is quite untenable when you consider that lava, however hot and
liquid it may be at the commencement of its journey, cannot flow on for
hundreds of miles, up hills, across ravines, and over plains, all the
time in streams of almost exactly equal width."
"That theory of yours holds no more water than mine, Ardan," observed
M'Nicholl.
"Correct, Captain," replied the Frenchman; "Barbican has a trick of
knocking the bottom out of every weaker vessel.
Pages:
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215