Note 2 — Chapter XVII · 1891. MORE OF KEELY’S THEORIES.—HIS TRADUCERS EXPOSED.
Reading edition
The universal physical law of molecular vibration is finely illustrated in the carbon pencils of the electric arc light used in some of the largest lighthouses. The molecular stir set up in the armatures of the dynamo machines by rapid magnetization and demagnetization is transmitted to the carbon points of the lantern, and reappears as a distinct musical tone. ↑