The Chancelade quarries near Perigneux, which caved in Oct. 22, 1885,
under circumstances that are still fresh in the minds of all, have
gained a celebrity that renders it unnecessary for us to revert to the
details of the catastrophe. It will suffice to recall the fact that
after the accident a private committee was formed for the purpose of
making an attempt to save the five victims who had been surprised in
the drifts, and who happened to be in the bottom levels.

[Illustration: FIG. 1.--PHOTOGRAPHIC EXPLORING APPARATUS.]

The Lippmann establishment at once offered to make a boring by means
of which it would be possible to communicate with the galleries in
which the men were imprisoned, but, despite the most active efforts,
success was found impossible. In order to satisfy public opinion, the
committee resolved to bore a well 12 inches in diameter to a depth of
23 feet, that should permit of reaching the gallery; but this did not
render the latter accessible. How was it to be seen what had occurred,
how was it to be made certain that the men were dead, and that all
hope of rescue must be abandoned? To Mr. Langlois, a Parisian
photographer, was confided an order to construct a special apparatus
which might be let down to the bottom of the well by a cord, and
which, being capable of operating from a distance, should furnish the
required information through sensitized plates. As may be seen, this
operation presented peculiar difficulties, although Mr. Langlois was
enabled to overcome these with much skill.

The photographic apparatus that the ingenious operator constructed was
contained in a metallic case that could be let down into the bore
hole. The upper and lower parts of the contrivance were provided with