When these different hatches were shut down, they had a sort of rubber covering which closed them hermetically tight, so that the water could not reach the interior when the boat plunged beneath the ocean.
As to the motor, which imparted such prodigious speed to the machine, I could see nothing of it, nor of the propeller.

However, the fast speeding boat left behind it only a long, smooth wake.

The extreme fineness of the lines of the craft, caused it to make scarcely any waves, and enabled it to ride lightly over the crest of the billows even in a rough sea.
As was already known, the power by which the machine was driven, was neither steam nor gasoline, nor any of those similar liquids so well known by their odor, which are usually employed for automobiles and submarines.

No doubt the power here used was electricity, generated on board, at some high power.

Naturally I asked myself whence comes this electricity, from piles, or from accumulators?
But how were these piles or accumulators charged?
Unless, indeed, the electricity was drawn directly from the surrounding air or from the water, by processes hitherto unknown.