With a small and imperfect machine he had seen several feet into the ground; with a great and powerful apparatus, such as he was now constructing, why should he not look down below the deepest point to which man's knowledge had ever reached?
Down so far that he must follow his descending light with a telescope; down, down until he had discovered the hidden secrets of the earth! The peculiar quality of this light, which gave it its great preeminence over all other penetrating rays, was the power it possessed of illuminating an object; passing through it; rendering it transparent and invisible; illuminating the opaque substance it next met in its path, and afterwards rendering that transparent.

If the rocks and earth in the cylindrical cavities of light which Clewe had already produced in his experiments had actually been removed with pickaxes and shovels, the lighted hole a few feet in depth could not have appeared more real, the bottom and sides of the little well could not have been revealed more sharply and distinctly; and yet there was no hole in the ground, and if one should try to put his foot into the lighted perforation he would find it as solid as any other part of the earth..