out. He'll tell us in good time. But when do you think we will finish
the-well, I don't know what to call it-I mean our aeroplane?"

"Oh, in about a month now. That's so, though, we haven't a name for
it. But we'll christen it after it's completed. Now if you'll tighten
up some of those bolts I'll get the gas generating apparatus in
readiness for another test."

A short description of the new airship may not be out of place now. It
was built after plans Mr. Sharp had shown to Tom and his father soon
after the thrilling rescue of the aeronaut from the blazing balloon
over Lake Carlopa. The general idea of the airship was that of the
familiar aeroplane, but in addition to the sustaining surfaces of the
planes, there was an aluminum, cigar-shaped tank, holding a new and
very powerful gas, which would serve to keep the ship afloat even when
not in motion.

Two sets of planes, one above the other, were used, bringing the
airship into the biplane class. There were also two large propellers,
one in front and the other at the rear. These were carefully made, of
different layers of wood "built up" as they are called, to make them
stronger. They were eight feet in diameter, and driven by a twenty-
cylinder, air-cooled, motor, whirled around at the rate of fifteen
hundred revolutions a minute. When operated at full speed the airship
was capable of making eighty miies an hour, against a moderate wind.

But if the use of the peculiarly-shaped planes and the gas container,
with the secret but powerful vapor in it were something new in airship
construction, so was the car in which the operator and travelers were
to live during a voyage. It was a complete living room, with the