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.




CHAPTER IV

THE MISSION OF SAMUEL BLOCK


Not far from the works at Sardis there was a large pond, which
was formed by the damming of a stream which at this point ran
between high hills. In order to obtain a sufficient depth of