Hawkins electrical guide ... : questions, answers & illustrations : a progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications ; a practical treatise (1914)
Hawkins, N. (Nehemiah), 1833-1928 · New York : T. Audel & Co. · leaf 352
The humming sound peculiar to alternating current arcs is due to theexpansion and contraction of the arc stream caused by the rise andfall of the current. These vai iations produce corresponding vibrations inthe adjacent air, and produce a hum variable in pitch with the frequency. The hissing sound… … BRIGHTYELLOW VERY LIGHTPURPLE BRIGHTYELLOW LOWERFLAMECARBON Fig. 3,355—Long burning flame arc. Electrode life 100 or more hours. Electrodes are about% inches diameter by 14 long, arc placed within a globe which restores the arc supply. Theunused portion of the upper electrode is used for trimming…
Electrical engineering
Internet Archive · Brigham Young University · Public Domain Mark 1.0. Free to use for anything.
![An illustration from The Telegrapher [microform] (1864)](https://img.insideoutlibrary.com/img/200/ia-telegrapher05nati-141-88.webp)
