File:Bell telephone magazine (1922) (14755612482).jpg

Identifier: belltelephonemag23amerrich (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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ment of techniques and instrumentsfor precision measurement. One of the most important ele-ments of undersea warfare is under-water sound, since radio is ruled outby the conductivity of sea water. Atthe beginning of our attack on prob-lems of underwater sound, we under-took to develop methods of measure-ment. Automatic means for measur-ing the performance of underwatergenerators and receivers of soundwere developed to the point that inthe course of a few minutes tiie re- 1944-^45 Bell Laboratories in the War ^-2>^ sponse of a device could be deter-mined with a high degree of accuracycontinuously over a frequency rangefrom 50 cycles to 100 kilocycles. De-vices for producing and detecting un-derwater sounds had previously beendesigned largely by cut-and-try meth- among them is echo-ranging equip-ment which represents a great ad-vance over the preceding art. Againour measuring techniques were madeavailable to other development or-ganizations with consequent benefitsto their producers.
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Field artillery radio sets, such as the one installed in this command car, link forward observers with rifle and howitzer batteries in the rear. Similar sets are used for communication between tanks ods and without the benefit of quanti-tative knowledge of their perform-ance. We supplied the means to de-sign on the basis of precise knowl-edge. Proceeding in this manner, wedeveloped new types of underwatersound instruments that have provedvery valuable in the war. Included The development of the electricalgun director comprises another im-portant segment of our war program.This is a situation in which we pro-posed an electrical solution of a taskwhich was being performed by a me-chanical device. This solution makesuse of electronic tubes and circuits 236 Bell Telephone Magazi)ie WINTER and of other components developedoriginally for communication pur-poses, and its success is now fullyproved by its having been adopted asstandard equipment in both Britishand American Armies. It played a

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