"Ay, and you'd have well earned it!" said the sailors.

Thus passed the long evenings on the forecastle in
merry chat, and during the same time the doctor went on
with his instructive discourses.

One day the conversation turned upon the means of
directing balloons, and the doctor was asked his opinion
about it.

"I don't think," said he, "that we shall succeed in finding
out a system of directing them. I am familiar with
all the plans attempted and proposed, and not one has
succeeded, not one is practicable. You may readily
understand that I have occupied my mind with this subject,
which was, necessarily, so interesting to me, but I have
not been able to solve the problem with the appliances
now known to mechanical science. We would have to
discover a motive power of extraordinary force, and
almost impossible lightness of machinery. And, even then,
we could not resist atmospheric currents of any considerable
strength. Until now, the effort has been rather to
direct the car than the balloon, and that has been one
great error."

"Still there are many points of resemblance between a
balloon and a ship which is directed at will."

"Not at all," retorted the doctor, "there is little or no
similarity between the two cases. Air is infinitely less