"Well, reaching that neutral point be it;" replied Ardan, "but, once
more, I should like to know how they have been able to come at the
necessary initial velocity of 12,000 yards a second?"

"Nothing simpler," answered Barbican.

"Could you have done it yourself?" asked the Frenchman.

"Without the slightest difficulty. The Captain and myself could have
readily solved the problem, only the reply from the University saved us
the trouble."

"Well, Barbican, dear boy," observed Ardan, "all I've got to say is, you
might chop the head off my body, beginning with my feet, before you
could make me go through such a calculation."

"Simply because you don't understand Algebra," replied Barbican,
quietly.

"Oh! that's all very well!" cried Ardan, with an ironical smile. "You
great _x+y_ men think you settle everything by uttering the word
_Algebra_!"

"Ardan," asked Barbican, "do you think people could beat iron without a
hammer, or turn up furrows without a plough?"

"Hardly."

"Well, Algebra is an instrument or utensil just as much as a hammer or a