[MBLB2049], Letter from Charles Batchelor to Charles Pitt Edison, May 7th, 1879


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[MBLB2049], Letter from Charles Batchelor to Charles Pitt Edison, May 7th, 1879

Editor's Notes

Yours of April 21st just to hand. We are exceedingly sorry to hear of Adam's deat through your telegram and hope you will do all you can to fix matters for his wife. As Gouraud reported he was so sick, Edison had decided to recall him and had already sent the telegram, thinking he would have a better chance to get well here. Gouruad is here at present and we are making 50 telephones for Central System there, whch he will probably take with him. Your are right insupposing the width of the spring has considerable to do with the proper working of the motograph the longer the line the narrower the springs and even in Laboratory out of 10 different widths I find 1/8 to 3/16 wide by far the best. One of our first ideas on the motogh was that it form H. gas under the stylus but later we have come to the conclusion that it might be due to capillary action; the passage of the current altering the capillary force, acting in the pores of the chalk so as to drie the moisture away from the surface. The new telephone is simply immense. Next Scribner will have a picture of it and I shall send you one. We have no difficulty in working both ends equally loud and in cases like central systems worked the line battery on at central station so as to have it in smae direction for both receivers. We have also devised for the call a 12 cell battery that goes inside a Leclanche battery jar and is just the best thing you ever saw, it is an open circuit battery and will last we judge 12 months. This is the connection of the instrument working with Central station [drawing] as far as I know at present Transmitter will be made with short funnel so that if you talk any[where] within six inches it is all OK. We shall put on a a bell instead of a sounder and as you see we use a double point key in order to prevent any man from having his battery closed when not working. The permanent line battery i put on at Central station in this manner [drawing]; so that polarity [is] always right for both receivers. The magnet you see is a 500 ohm German silver magnet which gives resistance to the leg and also tells when they have done talking. I sent you a book entitled `Edison and his inventions' did you get it? Send me by mail [if] yu can Du Moncels new book on Tel Phono etc Sent you Herald with obituary of Jim what do you think of it i should like to know the address of his relatives in Scotland so I could send some.
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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
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