but I told you, M. Aronnax, that the pumps of the Nautilus allow me to store the air under considerable pressure, and on these conditions the reservoir of the apparatus can furnish breathable air for nine or ten hours.” “I have no further objections to make,” I answered; “I will only ask you one thing, Captain—how can you light your road at the bottom of the sea?” “With the Ruhmkorff apparatus, M. Aronnax; one is carried on the back, the other is fastened to the waist. It is composed of a Bunsen pile, which I do not work with bichromate of potash, but with sodium. A wire is introduced which collects the electricity produced, and directs it towards a particularly made lantern. In this lantern is a spiral glass which contains a small quantity of carbonic gas. When the apparatus is at work this gas becomes luminous, giving out a white and continuous light. Thus provided, I can breathe and I can see.” “Captain Nemo, to all my objections you make such crushing answers, that I dare no longer doubt. But if I am forced to admit the Rouquayrol and Ruhmkorff apparatus, I must be allowed some reservations with regard to the gun I am to carry.” “But it is not a gun for powder,” answered the Captain. “Then it is an air-gun.” “Doubtless! How would you have me manufacture gunpowder on board, without either saltpetre, sulphur, or charcoal?”