Bell telephone magazine (1922) (14756477345)

Identifier: belltelephonemag09amerrich (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

Text Appearing Before Image:

hones, Mr. Holmes was in possession of a small experi-mental exchange with five subscribers, whose lines were repeat-edly interconnected, and many conversations were exchanged,the burglar alarm apparatus being employed to transmit thecall signals. A public exhibition of th£ working of this system was givenon May 17, 1877, on which occasion spectators assembled atthe banking offices of Brewster, Bassett and Company talkedwith the Holmes central office and the Williams shop, andcornet solos, played at the Holmes office, were plainly heard atthe other two points. This exhibition was noted in the Boston Evening Transcript of the following day, which reportedthat conversation was carried on between the several pointsconnected with perfect ease. This experimental exchange was discontinued after being inoperation about two weeks. The original switchboard waspreserved by Mr. Holmes, however, and is now in the BellSystem Historical Museum at 463 West Street, New York City. 206 m^^^\~^ TT^X^^M

Text Appearing After Image:

QRIGIHAL TELEPHONE EXCHANGE SWITCH BOARD ■Pi^OPEi\TY OF E.T.HOl^ME^. ■T>E;j!iiNe» ANJi VSBU BY H i W IN T H KKC-STON, MAY. 13^5. mmm m m\ Figure 1 (Above). Building at 342 Washington Street, Boston, Mass., in which thecentral office of the Holmes Burglar Alarm Company was locatedFigure 2 (Below). The first telephone switchboard. It was designed by Mr.E. T. Holmes, and used for the first interconnection of lines equipped with telephones.The plug and block switches are shown in readiness for a call to be made. THE FIRST TELEPHONE SWITCHBOARD Coming now to the method of operation of the switchboard,Figure 3 is a circuit diagram showing the substation and centraloffice apparatus and connections for the lines of two subscrib-ers, B and D, the apparatus being shown in readiness for a callto be made. At the central office, the subscribers lines werepermanently connected to the top plates of the plug and blockswitches. (As will be seen from Figure 2, there were six ofthese switches, f

1877 in boston bell telephone magazine 1930 telephone exchanges in the united states western electric switchboards book illustrations telephone bell telephone company american telephone and telegraph company history of technology images from internet archive

1922

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