[D8955ADN], Letter from John W Gentry to Thomas Alva Edison, November 14th, 1889


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[D8955ADN], Letter from John W Gentry to Thomas Alva Edison, November 14th, 1889

Editor's Notes

Dear Sir: Polonius, I believe once said “Brevity is the soul of wit” so I will be as brief as possible that I may not impose to much upon your valuable time.##Both my chief and I have one of your graphophones, upon which we have been operating for about a week. In receiving the reproduction it occurred to me, the first few days of attempting it, that there was too much confusion of other sounds, coming from the cylinder, to get clearly the words. This at once set me to thinking how the matter might be remedied, and this morning, I made an experiment which gave me very satisfactory results; and believing that you would be interested in it, decided to write you on the subject.##The secret I claim to have discovered, is simply the placing of a core (transferable) in the paper cylinder. In making my experiment I used a soft rubber tube, slightly shorter than the cylinder (so as not to interfere with its proper adjustment to eh holders) and a fraction less in diameter. This rubber tube I coated thinly with cotton, using mucilage and cotton batting, the surplus of the latter being carefully brushed off after drying. I then found that my tube fitted closely and neatly into the paper cylinder. IN using this first appliance I find that I get words much more distinctly than formerly, and am less worried by the harsh sounds, as formerly sent forth by the cylinder.##I believe that a solid rubber core (soft), fitting the cylinder closely, would meet with still better results; and also think that some hard wood, with lint or rubber covering, would give good results. However, as you are thoroughly posted both as to the best nonconductors, as well s to the best conductors, of sound, I am sure you will give my discovery a scientific and practical test. Of course the core is to be used when dictating, as well as when receiving, the message or letter, and is transferable.##I am also impressed with the idea that a diminutive, pointed-toothed (like the teeth of a cross-cut saw) wheel might be used for contact with the cylinder instead of the naked point of the needle, and thereby destroy entirely the grating sound from the needle. This is, however, only a surmise, on the practicability of which I have neither the facilities or the means for testing. Were I in the condition to do so and met with a success, you would be the first advised of it.##Simply for the sake of identification I will say that my home is in Charleston, West Va.; am a brother-in-law of Senator John E. Kenna, of the same state, and am now, and have been for several years, connected with the U.S. Geological Survey.##In the event of either of my suggestions proving of value to you, as I am a poor government clerk with a large family to support, I leave it entirely with you to make such acknowledgment to me as you may deem fit.##My office address is U.S. National Museum, Washington, D.C., where some of the Survey offices are located.##Trusting to have a line at your convenience, I am, Very respectfully yours, Jno. W. Gentry <TAE marg: Write him & say I did not design the graphone but only phonogh & that all graphones are to be replaced with new phonogph shortly give no scratching sounds E>




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