“That’s just what I think she is,” said Lockyer with a laugh.
“And these pumps here?” asked Ned, indicating an intricate mass of machinery painted red and green, and brass-mounted.
“Those are the pumps for regulating the rising and lowering apparatus. As you, of course, know, below us and in the extreme bow and stern are tanks which, when we wish to sink, are filled with sea-water. If we want to rise and float on the surface, we set our compressed air at work and drive out the water. The empty tanks, of course, supply sufficient buoyancy to float the boat.”
“And you have no storage batteries or gasolene engine or electric motors,” gasped Ned.
“No. I think that in the Lockyer boat we have successfully abolished the storage battery, with its dangerous, metal-corroding fumes, and the bother of having two sets of engines, the gasolene for the surface and the electric for under-water work. We have a dynamo, however, to furnish current for lighting and other purposes.”
“How do you get your air-supply when you are running under water?” asked Ned, his face beaming with interest.
“When the submarine is afloat you will see that alongside her periscope she will carry another pipe. This is of sufficient length to allow us to run twenty feet under water and still suck in air. Like the periscope pipe, this air-tube will telescope up, folding down inside the submarine. When we are too far below to use this device, we run on air already compressed in reserve tanks. We can carry enough for five hours of running without renewing it. In case the pressure is not high enough, we expand it,—heating it by electric radiators.”
“And your fresh air?”
“Still compressed air,” laughed the inventor. “We drive out the old foul atmosphere through specially devised valves, the fresh air taking the place of it.”
“Then the only time you have to utilize the gas is in starting your engine?” asked Ned.