This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
The magnetite arc employs a copper disk as one electrode; and a magnetite stick - formed by forcing magnetite, to which titanium salts are usually added, into a thin sheet steel tube is used as the other electrode. This lamp gives a luminous arc of good efficiency and the magnetite electrode is not consumed as rapidly as the treated carbons with the result that magnetite lamps do not require trimming as frequently. The life of the magnetite electrode as at present manufactured is from I70 to 200 hours. A diagram of the connections of this lamp as manufactured by the General Electric Company is shown in Fig. 12. The magnetite electrode is placed below. The copper electrode has just the proper dimensions to prevent its being destroyed by the arc and yet it is not large enough to cause undue condensation of the arc vapor. Direct current must be used with this lamp, the current passing from the copper to the magnetite. Table XI gives some general data on the flaming arc, while Figs.
Fig. 41. Clock Feeding Mechanism for Luminous Arc Lamp.
LIVING ROOM IN ALPHA DELTA PHI CHAPTER-HOUSE AT CORNELL UNIVERSITY, ITHACA, N. Y.
Dean & Dean, Architects, Chicago, I11.
Oak Stained a Gray Green and Waxed; Furniture to Match; Plaster Stained and Waxed. For Plans and Exterior, See Vol. III, Pages 282 and 298: for other Interiors, see Page 154 in this Volume.
GAS AND ELECTRIC FIXTURE IN LIVING ROOM OF ALPHA DELTA PHI CHAPTER-HOUSB AT CORNELL UNIVERSITY, ITHACA, N. Y.
Dean & Dean, Architects, Chicago, Ill.
Fig. 42. Diagramof Connections for Magnetite Arc Lamp.
43 and 44 give typical distribution curves. The advantages of the flaming arc over lamps using pure carbon electrodes are: High efficiency; better light distribution; and better color of light for some purposes. A greater amount of light can be obtained from a single unit than is practical with the carbon arc. The disadvantages lie in the frequent trimming required and the expense of electrodes. Flaming arcs have been introduced abroad, especially in Germany, to a much greater extent than in the United States.
Watts per Mean Spherical c. p.