Note 18 — Chapter III · THE ILLUMINATING APPARATUS OF LIGHTHOUSES.

To be more exact than have been the majority of authors who have written on lighthouses, we must add that a small revolving apparatus, with three reverberators (probably with spherical shells), had been planted at the mouth of the port of Marstrand, in Sweden, prior to 1783. The French engineer, however, had thought out the invention for himself, in ignorance that it had been elsewhere realized, and his was the merit of imagining a system so complete and so rational in all its parts, that nothing has since been added to or taken from his conception.

M. Leonel Reynard informs us that we are likewise wrong in attributing to Argand the idea of a lamp with a double current of air. It is to Teulère that it should, in the main, be attributed. However, this engineer, who has asserted the priority of his claim to the invention of the reflectors, and the system of eclipses, has not insisted upon that of the lamp. He limits himself to saying that Argand entertained the same idea as himself, and derived great profit from it.