oyce went to the water-motor. This was a curious, but extremely simple affair. There was a glass box, ribbed with polished steel, about the size and shape of a cigar box, which was full of water. Leading away from this, to the bow and stern of the shell, were two small pipes. The pipes were greatly thickened for a period of three feet or so, directly under the little tank, and were braced by bed-plates so heavy as to look all out of proportion. Around the thickened parts of the pipes were coils of heavy, insulated copper wire. There were no valves nor cylinders, no revolving parts: that was all there was to the "motor."
Joyce didn't yet understand the device. The water dripped from the tank, drop by drop, to be abruptly disintegrated, made into an explosive, by being subjected to a powerful magnetic field induced in the coils by a generator in the bow of the shell. As each drop of water passed into the pipes, and was instantaneously broken up, there was a violent but controlled explosion—and the shell was kicked another hundred miles ahead on its journey. That was all Joyce knew about it.
He threw the bow switch. There was a soft shock as the motor exhausted through the forward tube, slowing their speed.
"Turn on the outside generator propellers," ordered Wichter. "I think our batteries are getting low."
Joyce slipped the tiny, slim-bladed propellers into gear. They began to turn, slowly at first in the almost non-existent atmosphere.
"Four hundred miles," announced Wichter. "How's the temperature?"
Joyce stepped to the thermometer that registered the heat of the outer wall. "Nine hundred degrees," he said.
"Cut down to a thousand miles an hour," commanded Wichter. "Five hundred as soon as the motor will catch that much. I'll keep our course straight toward this crater. It's in wells like that, that we'll find livable air—if we're right in believing there is such a thing on Zeud."
