"Ha! ha! ha!" roared Ardan, laughing till the tears came. "Now I
understand why the poor Captain made me no reply all the time, and
looked at me with such a hapless woe-begone expression of countenance.
The fact is, Barbican, that shock was too much both for M'Nicholl and
myself. You are the only man among us whose head is fire-proof,
blast-proof, and powder-proof. I really believe a burglar would have
greater difficulty in blowing your head-piece open than in bursting one
of those famous American safes your papers make such a fuss about. A
wonderful head, the Boss's, isn't it M'Nicholl?"

"Yes," said the Captain, as slowly as if every word were a gem of the
profoundest thought, "the Boss has a fearful and a wonderful head!"

"But now to business!" cried the versatile Ardan, "Why do you think,
Barbican, that we are at present beyond the limits of the terrestrial
atmosphere?"

"For a very simple reason," said Barbican, pointing to the chronometer;
"it is now more than seven minutes after 11. We must, therefore, have
been in motion more than twenty minutes. Consequently, unless our
initial velocity has been very much diminished by the friction, we must
have long before this completely cleared the fifty miles of atmosphere
enveloping the earth."

"Correct," said the Captain, cool as a cucumber, because once more in
complete possession of all his senses; "but how much do you think the
initial velocity to have been diminished by the friction?"

"By a third, according to my calculations," replied Barbican, "which I
think are right. Supposing our initial velocity, therefore, to have been