File:The practical telephone handbook and guide to the telephonic exchange (1906) (14569606919).jpg

Identifier: practicaltelepho00pool (find matches)
Title: The practical telephone handbook and guide to the telephonic exchange
Year: 1906 (1900s)
Authors: Poole, Joseph
Subjects: Telephone
Publisher: New York, Macmillan Co.
Contributing Library: Northeastern University, Snell Library
Digitizing Sponsor: Boston Library Consortium Member Libraries

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Fig. 504.—Poulsens Telegraphone, Steel Wire Type which is run past the magnets at the rate of about 10 feet persecond, the length being sufficient for about 30 minutes ofconversation. When the record has been made the motor is switched overso as to drive the other bobbin, and rewind the wire on the samebobbin it was on at the start. The telephone receiver is thenswitched into connection in place of the transmitter, and themotor again switched on to drive the other bobbin, so as toreproduce the sounds. It has been proposed to use the instrument for the recording 56° PRACTICAL TELEPHONE HANDBOOK of conversations held over an exchange telephone line, thechief idea being that, if a subscriber is absent, the fact ofhis bell being rung automatically starts and switches in thetelegraphone, and records the callers message ready to be re-produced on the return of the subscriber. There are certain difficulties, however, in connection with
Text Appearing After Image:
Fig- 505.—Steljes Typewriting Telegraph such use of the instrument—one of which is that, whilst the re-productions are remarkably clear and free from extraneousnoises, the sounds are comparatively faint, so that, unless thereare very favourable conditions in recording, the reproductionsare too faint for practical use. Another important point isthat the results are very poor on a common-battery circuit.Steljes Typewriting Telegraph.—This is a more practi MISCELLANEOUS APPLICATIONS 56i cal instrument, used as an adjunct to an exchange telephoneset, for the purpose of recording a message at another sub-scribers office provided with a similar instrument. Therecord can be made in the absence of the subscriber, therecording apparatus at the distant end being started anddriven by the magneto-electric currents generated by thetransmitting machine. Fig. 505 gives a view of the complete i 1l • _^5^: — _, M Fig. 506.—The Telautograph, General View instrument, which is really a modifi

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