that he suggests. He knows every piece of equipment on board, and can
pick whatever is best suited for the purpose."

As Dick sat down, John got to his feet. "This is one time that I'm ahead
of you. While you've been talking I've been planning a way to do just
that. There's an extra firing tube that can hold the pressure we want.

"Fuel for all the blasts is compressed in one chamber, then discharged
through any desired tube. If we put the water under the pressure, with
the hydraulic system, and let it seep into the chamber at a set
rate--_it might work_! Valves can control the steam perfectly, and
regulate the flow to whatever is desired.

"The tube will have to be shut off from the fuel tank every few hours,
to be filled. Preheating the water will develop steam pressure, and it
won't draw enough from the hydraulic system to affect the operation of
the blasts.

"What do you say, shall we try it? It means shutting off all but the
emergency tube for several hours, and it will be _cold_!"

* * * * *

Within five minutes they were hauling the heavy tube from the storage
room. In an hour everything was ready to assemble, and each man knew
exactly what work he was to do. A pipe line was run from the water
tanks, to fill the steam chamber in position.

Dick was building an electric heating unit to encase the entire tube,
which could be regulated for any desired temperature.

Half of the rest period had passed when the chamber was finished and
they were ready to cut an opening in the compression unit. Perspiration
poured down the body of every man, but not from the exertion. Each
minute that passed ate deeper into the fuel. If water couldn't replace
the liquid, they were helpless.

They wanted to install the tube, while the women were asleep. The ship
would be too cold for comfort for a long time after the blasts could be
started again. When the heating units in the hull were shut off it would
become freezing inside.

Men raced through the ship, stopping at their staterooms on the way.
Dick dropped three extra covers over Dolores without disturbing her,
then slipped into the heaviest clothing that he owned.

Each man was occupied in his own room, in the same way. Heavy coats were
taken to the men at the controls while the remainder of the crew were
sent to a room with an emergency heating unit.

In fifteen minutes they were back at the compression chamber, and at the
touch of a butt