"I never thought your ears could be so easily deceived, Captain," cried
Ardan, quickly, "Let us try it again," and, flapping his ribs with his
arms, he gave vent to a crow so loud and natural that the lustiest
chanticleer that ever saluted the orb of day might be proud of it.

The Captain roared right out, and even Barbican snickered, but as they
saw that their companion evidently wanted to conceal something, they
immediately assumed straight faces and pretended to think no more about
the matter.

"Barbican," said Ardan, coming down the ladder and evidently anxious to
change the conversation, "have you any idea of what I was thinking about
all night?"

"Not the slightest."

"I was thinking of the promptness of the reply you received last year
from the authorities of Cambridge University, when you asked them about
the feasibility of sending a bullet to the Moon. You know very well by
this time what a perfect ignoramus I am in Mathematics. I own I have
been often puzzled when thinking on what grounds they could form such a
positive opinion, in a case where I am certain that the calculation must
be an exceedingly delicate matter."

"The feasibility, you mean to say," replied Barbican, "not exactly of
sending a bullet to the Moon, but of sending it to the neutral point
between the Earth and the Moon, which lies at about nine-tenths of the
journey, where the two attractions counteract each other. Because that
point once passed, the Projectile would reach the Moon's surface by
virtue of its own weight."