The Thomas A. Edison Papers Digital Edition

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Metadata

Title

[LB004489], Letter from Charles Batchelor to Edward Hibberd Johnson, July 16th, 1879

Editor's Notes

We ship you today four (4) telephones of a new pattern, the receiver on an independent arm which swings down to your ear and the transmitter stationary ina box screwed to the wall. Edison has decided on this as the telephone best adapted to do the work for this reason: that we stand in a disadvantageous position in regard to the other telephones inasmuch as they put the instruments to the ear (thus shutting out all extraneous sound) when they want to catch weak sounds, whilst our diaphragm is so far away, that weak sounds are difficult to get in a noisy room. Now by putting the receiver on an arm, we get it just as loud, and also have it close to the ear. In this sahpe as ou will see it is a much cheaper instrument to make. These telephones are supplied with chalks made of chalk and phosphate of Soda, we having adopted that as the stndard chalk for the reason that it is always the same, nothing comes from it, needs very little wetting, and glazes so nicely. The receivers we send, are on arms that are unscrewed from base, and fastened against the side of box. The back of receiver unscrews out, thus giving you a chance to wet it the chalk with a camels hair brush if necessary. If you wish to take a chalk out you will find on the worm wheel shaft, a long sleeve, which pull towards the worm, and the shaft divided in two lengths, now move the piece this [next off bottom of page] unscrews the set screw in chalk mandrel, and pull short shaft out, thus getting your chalk out. On the 21st we shall send you eight more (4) of which will have a new transmitter on which I think you will like because it can never get out of adjustment, we call it the inertia telephone because it works by inertia, the whole working part being fast on the centre of the diaphragm. Page 4 of this contains a diagram of the connections of the new bracket. [drawing follows]

Author

Batchelor, Charles

Recipient

Johnson, Edward Hibberd

Mentioned

Edison, Thomas Alva

Date

1879-07-16

Type

Letter

Subject

Telephone

Chemicals, chemical products, and chemical processes

Folder ID

LB004-F

Microfilm ID

80:107

Document ID

LB004489

URL

https://edisondigital.rutgers.edu/document/LB004489

Rights

Thomas Edison National Historical Park

Publisher

Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University

Has Version

Archive.org Viewer, Microfilm Series Reel 80

License

CC0 1.0 Universal

Item sets

[LB004-F] LB-004 (1878-1879)