Contrary to what one might think, especially in connection with an opera-house, the “organ” is not a musical instrument. At that time, electricity was employed only for a very few scenic effects and for the bells. The immense building and the stage itself were still lit by gas; hydrogen was used to regulate and modify the lighting of a scene; and this was done by means of a special apparatus which, because of the multiplicity of its pipes, was known as the “organ.” A box beside the prompter’s box was reserved for the chief gasman, who from there gave his orders to his assistants and saw that they were executed. Mauclair stayed in this box during all the performances.

But now Mauclair was not in his box and his assistants not in their places.

“Mauclair! Mauclair!”

The stage-manager’s voice echoed through the cellars. But Mauclair did not reply.