And he made known to them the result of his observations.
According to him, a cavity, more or less considerable, must exist in the mass of granite which supported Prospect Heights, and he intended to penetrate into it.

To do this, the opening through which the water rushed must first be cleared, and the level lowered by making a larger outlet.

Therefore an explosive substance must be manufactured, which would make a deep trench in some other part of the shore.

This was what Harding was going to attempt with the minerals which nature placed at his disposal.
It is useless to say with what enthusiasm all, especially Pencroft, received this project.

To employ great means, open the granite, create a cascade, that suited the sailor.