for the purpose, formed the main part of both bodies.

The upper hull was one hundred feet long and twenty feet in diameter
at the widest part. It tapered to points at either end. It was
attached to the lower hull by strong braces, at either end, while from
the center there extended a pipe which connected with the lower
section. This pipe was intended to convey the lifting gas to the part
which corresponded to the bag of the balloon, save that it was of
metal instead of silk, or rubber as is usual.

There were two reasons for this. One was that it would not be liable
to puncture, particularly in the proposed underground trip, and the
other was that it did not have to be so large as a cloth bag would
have had to be. It was also a permanent part of the ship, and on a
voyage where part of the time the travelers would be in the air and
part on the water, and when the change from one to the other would
have to be made quickly, this was necessary. It would have taken too
long to raise the ship in the air had a cloth bag been used to contain
the gas.

The lower hull or main part of the craft was one hundred and fifty
feet long, and forty feet through at the largest part, in the centre.

It was divided into four sections. The forward one contained the
sleeping quarters of Professor Henderson and his crew. There was a
small stateroom for each one. Above was a conning or observation
tower, reached by a small flight of steps. From this tower the ship
could be steered, stopped and started, as could also be done from the
engine room, which was in the after part of the hull.