Cyclopedia of applied electricity : a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric lighting, electric railways, power stations, switchboards, power transmission, alternating-current machinery, telegraphy, etc. (1916)
American Technical Society · Chicago : American Technical Society · leaf 301
the Bulb. After flashing, the filament is sealed inthe bulb and the air exhausted through the tube A in Fig. 1, whichshows the lamp in different stages of its manufacture. The ex-haustion is accomplished by means of mechanical air pumps, supple-mented by Sprengle or mercury pumps and chemicals.…
Electrical engineering
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