• Ruhmkorff’s apparatus consists of a Bunsen pile worked with bichromate of potash, which makes no smell; an induction coil carries the electricity generated by the pile into communication with a lantern of peculiar construction; in this lantern there is a spiral glass tube from which the air has been excluded, and in which remains only a residuum of carbonic acid gas or of nitrogen. When the apparatus is put in action this gas becomes luminous, producing a white steady light. The pile and coil are placed in a leathern bag which the traveller carries over his shoulders; the lantern outside of the bag throws sufficient light into deep darkness; it enables one to venture without fear of explosions into the midst of the most inflammable gases, and is not extinguished even in the deepest waters. M. Ruhmkorff is a learned and most ingenious man of science; his great discovery is his induction coil, which produces a powerful stream of electricity. He obtained in 1864 the quinquennial prize of 50,000 franc reserved by the French government for the most ingenious application of electricity. ↩