St. John, Thomas M. (Thomas Matthew), b. 1865 · New York, T. M. St. John · leaf 141
Fig. 214. HOW LIGHT IS PRODUCED BY ARC LAMPS. 139 Fig. 208 shows the mechanism by which the carbonsare regulated. Fig. 209 shows a form of double carbon,or all-night lamp, one set of carbons being first used, the
Electricity
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
