File:Bell telephone magazine (1922) (14733142616).jpg

Identifier: belltvol20elephonemag00amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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Text Appearing Before Image:
Fig. 5. A 6-kilowatt Automatic Gasoline Emergency Set Aulomalic control equipment starts this engine when the battery voltage drops to a pre-determined value, and stops it when the battery reaches full charge. The cycle will repeat,without attention, as long as normal power supply is cut off
Text Appearing After Image:
Fig. 6. A 120-kilowatt Gas Emergency Engine of 20 Years Ago Compare this set with the one shown in Figure 3, which is about the same size as this but has nearly five times the capacity i9^i Engines for Defense 79 automobile engine. Some of the earlyBell System installations, however,utilize gas as fuel and are cooled bycity running water. In order thatthese engines may be independent ofall supply services that might be inter-rupted in times of emergency, consid-eration is now being given to a pro-gram of arranging them for operationon gasoline, with radiator cooling.The student of engine design will beinterested in comparing Figure 6,which illustrates one of the older gasengine sets installed about 20 years ago, with Figure 3, which shows anengine of about the same size buthaving five times the capacity. And so, if and when the continuedfunctioning of the central office bat-teries giving electrical life to tele-phone facilities is threatened, therewill be means readily at hand withwhi

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