But by communication with the water, whose external pressure it indicates, it gives our depth at the same time." "And these other instruments, the use of which I cannot guess ?" "Here, Professor, I ought to give you some explanations.

Will you be kind enough to listen to me ?" He was silent for a few moments, then he said: "There is a powerful agent, obedient, rapid, easy, which conforms to every use, and reigns supreme on board my vessel.

Everything is done by means of it.

It lights, warms it, and is the soul of my mechanical apparatus.

This agent is electricity." "Electricity ?" I cried in surprise.
"Yes, sir." "Nevertheless, Captain, you possess an extreme rapidity of movement, which does not agree well with the power of electricity.