don't see how you carry one on your machine."

"Here it is," was the answer, and a deflated rubberized silk bag
was produced from a locker back of the pilot's seat. "This is the
latest idea in airship wireless," went on Captain Grantly, as he
directed the lieutenants to get out the rest of the apparatus. "We
carry with us a deflated balloon, which will contain about two
hundred cubic yards of lifting gas. The gas itself, greatly
compressed, is in this cylinder. There's enough for several
chargings.

"We fill the balloon, and attach to it our aerial wires. The
balloon takes them up about four hundred feet--the wires weigh about
twenty pounds, I might say. Then we carry a light sending
instrument. It has a considerable range, though we can receive
messages from a much greater distance than we can send, as our force
for a sending current is limited."

As he was talking the others were working, and the cadets looked on
interestedly. The drill had been abandoned, and officers and
students crowded up near the army aviators to see what was going
on.

With a sharp hiss the compressed gas rushed from the containing
cylinder into the deflated balloon. The silken sides puffed out,
losing their wrinkles. The balloon gradually assumed larger
proportions.

"Ready with the wires?" asked Captain Grantly.