If the weather is fine I think that I shall obtain the longitude of the island with an approximation of some degrees." "Without instruments, without sextant ?" asked Gideon Spilett.
"Yes," replied the engineer.

"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 archipelagoes 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 more than a hundred miles from an inhabited coast." "That is why," returned Harding, "I am going to try this evening to calculate the latitude of Lincoln Island, and to-morrow, at midday, I will try to calculate the longitude." If the engineer had possessed a sextant, an apparatus with which the angular distance of objects can be measured 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 the position of the island.

But as they had not one he would have to supply the deficiency.
Harding then entered the Chimneys.