“Besides,” added Spilett, “Lincoln Island is not in very high latitude, and the winters are probably mild. Did you not say, Cyrus that the thirty-fifth parallel corresponded with that of Spain in the other hemisphere?” “Yes,” said the engineer, “but the winter in Spain is sometimes very cold, with snow and ice, and we may have a hard time of it. Still we are on an island, and have a good chance for more moderate weather.” “Why, Mr. Smith?” said Herbert. “Because the sea, my boy, may be considered as an immense reservoir, in which the summer heat lies stored. At the coming of winter this heat is again given out, so that the neighboring regions have always a medium temperature, cooler in summer and warmer in winter.” “We shall see,” said Pencroff. “I am not going to bother myself about the weather. One thing is certain, the days are getting short already and the evenings long. Suppose we talk a little about candles.” “Nothing is easier,” said Smith. “To talk about?” asked the sailor. “To make.” “And when shall we begin?” “To-morrow, by a seal-hunt.” “What! to make dips?” “No, indeed, Pencroff, candles.” Such was the engineer’s project, which was feasible enough, as he had lime and sulphuric acid, and as the amphibia of the island would furnish the necessary fat. It was now June 4, and Pentecost Sunday, which they kept as a day of rest and thanksgiving. They were no longer miserable castaways, they were colonists. On the next day, June 5, they started for the islet. They had to choose the time of low tide to ford the channel; and all determined that, somehow or other, they must build a boat which would give them easy communication with all parts of the island, and would enable them to go up the Mercy, when they should undertake that grand exploration of the southwestern district which they had reserved for the first good weather. Seals were numerous, and the hunters, armed with their iron-spiked spears, easily killed half a dozen of them, which Neb and Pencroff skinned. Only the hides and fat were carried back to Granite House, the former to be made into shoes. The result of the hunt was about 300 pounds of fat, every pound of which could be used in making candles. The operation was simple enough, and the product, if not the best of its kind, was all they needed. Had Smith had at his disposition nothing but sulphuric acid, he could, by heating this acid with neutral fats, such as the fat of the seal, separate the glycerine, which again could be resolved, by means of boiling water, into oleine, margarine, and stearine. But, to simplify the operation, he preferred to saponify the fat by lime. He thus obtained a calcareous soap, easily decomposed by sulphuric acid, which precipitated the lime as a sulphate, and freed the fatty acids. The first of these three acids (oleine, margarine, and stearine) was a liquid which he expelled by pressure. The other two formed the raw material of the candles.