Soon Keeling Island disappeared from the horizon, and our course was directed to the north-west in the direction of the Indian Peninsula. From Keeling Island our course was slower and more variable, often taking us into great depths. Several times they made use of the inclined planes, which certain internal levers placed obliquely to the waterline. In that way we went about two miles, but without ever obtaining the greatest depths of the Indian Sea, which soundings of seven thousand fathoms have never reached. As to the temperature of the lower strata, the thermometer invariably indicated 4° above zero. I only observed that in the upper regions the water was always colder in the high levels than at the surface of the sea. On the 25th of January the ocean was entirely deserted; the Nautilus passed the day on the surface, beating the waves with its powerful screw and making them rebound to a great height. Who under such circumstances would not have taken it for a gigantic cetacean? Three parts of this day I spent on the platform. I watched the sea. Nothing on the horizon, till about four o’clock a steamer running west on our counter. Her masts were visible for an instant, but she could not see the Nautilus, being too low in the water. I fancied this steamboat belonged to the P. O. Company, which runs from Ceylon to Sydney, touching at King George’s Point and Melbourne.