CHAPTER XII.
ENTIRELY BY ELECTRICITY.
“Monsieur,” said he, as he indicated the instruments suspended against the walls of the room, “there is the apparatus necessary for the navigation of the Nautilus. Here, as in the other room, I have them always under my eyes, and they point out to me my exact situation and direction in mid-ocean. Some of them are known to you, such as the thermometer, which tells me the temperature of the Nautilus; the barometer, which tells me the weight of the air, and predicts changes of weather; the hygrometer, which marks the dryness of the atmosphere; the storm-glass, whose mixture decomposing, tells me of the approaching tempest; the compass, which guides me: the sextant, which, by the sun’s altitude, tells me my latitude; the chronometers, which show my longitude; and finally, the day and night telescopes, by which I can scrutinise all parts of the horizon when the Nautilus comes up to the surface of the sea.”
“These are the instruments in general use on board ship,” I said, “and I know their uses. But there are
