and above all the Southern Cross, which some days before the engineer had greeted on the summit of Mount Franklin.
Cyrus Harding gazed for some time at this splendid constellation, which has at its summit and at its base two stars of the first magnitude, at its left arm a star of the second, and at its right arm a star of the third magnitude. Then, after some minutes' thought, "Herbert," he asked of the lad, "is not this the 15th of April?"
"Yes, captain," replied Herbert.
"Well, if I am not mistaken, to-morrow will be one of the four days in the year in which the real time is identical with average time; that is to say, my boy, that to-morrow, to within some seconds, the sun will pass the meridian just at mid-day by the clocks. If the weather is fine I think that I shall obtain the longitude of the island within an approximation of some degrees."
"Without instruments, without sextant?" asked Gideon Spilett.
"Yes," replied Harding. "Also, since the night is clear, I will try, this very evening, to obtain our latitude by calculating the height of the Southern Cross, that is, from the southern pole above the horizon. You understand, my friends, that before undertaking the work of installation in earnest it is not enough to have found out that this land is an island; we must, as nearly as possible, know at what distance it is situated, either from the American continent or Australia, or from the principal archipelagos of the Pacific."
"In fact," said the reporter, "instead of building a house it would be more important to build a boat, if by chance we are not over a hundred miles from an inhabited coast."
"That is why," returned Harding, "I shall try this evening to calculate the latitude of Lincoln Island, and tomorrow, at mid-day, I will also try to calculate the longitude."
If the engineer had possessed a sextant, an apparatus which measures the angular distance of objects with great precision, there would have been no difficulty in the operation. This evening by the height of the pole, the next day by the passing of the sun at the meridian, he would obtain
