The Thomas A. Edison Papers Digital Edition

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Title

[LB033484], Letter from Thomas Alva Edison to George Edward Gouraud, November 8th, 1889

Editor's Notes

[typed except for partially illeg last sentence by TAE; signed by TAE. SELECTABLE? Technical reference] I mailed to you Wednesday last photographs of the improved phonograph which I have gotten up since my return home, and which, when I am able to send you one, you will find to be as simple a machine as can possibly be wished for. By inspecting the photographs you will observe that I have removed the kick-back altogether. The lever for raising the spectacle, which, in the shape of an angle rod is placed in front of the straight edge on the machines which you use, has also been removed, and the spectacle is now raised by an arm which protrudes beneath the lip of the former; when this lever is thrown up the spectacle is raised so that the recorder or reproducer point, as the case may be, is lifted off the phonogram and the travelling nut thrown out of gear, and when lowered brings either of these points and the travelling nut back into position for recording or reproducing. I have cut the spectacle itself in two and thrown one side away, using one diaphragm for recording and reproducing. The receiver (which in the other type of phonograph we used to refer to as a recorder and reproducer, there being two of them), is let into the spectacle in the usual way. Extending from the right-hand side of the recorder and attached to the same, is a small arm, which has a play up and down of about a quarter of an inch, and which when raised or lowered moves the receiver in a circle to the same extent. Attached to the diaphragm of the receiver are the two points, one for recording and the other for reproducing. When this arm is up against the adjusting nut, the reproducer point is in position, and when it is thrown down, the recording point is brought into play. In the photograph you will notice a wire bent over the top of the receiver and a shorter wire protruding upward to the left of this. This shorter wire is attached to the receiver and moves with it. The other is stationary. It is, therefore, obvious that these wires will be closer together when the lever of the receiver is thrown down than when it rests against the adjusting nut. The thimbles on the ends of the speaking tube and the listening tube have slots cut in them for these wires to enter and permit them to be set down over the thimble of the receiver. When the receiver is set for reproducing the speaking tube thimble cannot be placed over the receiver thimble owing to the wires not [unclear] and when the machine is set for recording the listening tubes cannot be used – or in other words, either of these tubes can be used only when the machine is set for the purpose for which the tube is intended. It forms a sort of yale look combination which prevents any mistake being made. ### I have taken away the screw on the side of the machine employed to secure the swinging centre that secures the brass cylinder, and replaced the same by a short pendulum, which, when raised, clamps the swinging centre, holding it firm, and when lowered releases it. This motion is much more rapid than the screw motion. The knife has been placed on the spectacle arm at the back, in a kind of steel box, which contains the movement that operates the knife. On the side of this box is a determining point which automatically adjusts the knife for the proper depth of chip. At the back of the box is a lever which works up and down. When this lever is pulled down it lowers the determining point until the latter just touches the surface of the phonogram, and at the same time locks the knife in proper position for the cut. After the cut has been taken, and it is necessary to bring the spectacle back to position for recording, the spectacle arm is raised as usual, and this motion throws the knife back by raising the lever at the back of the knife box, thus eliminating the possibility of the cylinder being cut through thoughtlessness or carelessness. The arm which reaches from the sleeve on the backrod to the 100 thread screw is a split spring which carries two travelling nuts, one on each side of the split. Either one of these nuts will carry the spectacle along as well as the two together, which reinforces this part against accident. This machine possesses great advantage in the way of recording, for the following reason: The recording point is a fraction of an inch to the right of the reproducing point. When the record is being made and the speaker desires to listen to the context of his subject, it is only necessary to throw up the lever attached to the receiver, keeping the speaking tube in his hand; the receiver point now comes into position and being, as I have said, the fraction of an inch behind the recorder it will repeat about twenty-five words of the dictated matter without moving the spectacle at all. So far as recording and reproducing are concerned, all adjustments have been done away with. After the phonogram has been placed on the cylinder, the operation consists in simply dropping the spectacle and going ahead. As the phonogram is shaved off and its diameter reduced the difference is compensated for automatically by the recording and reproducing points which have an upward and downward movement that renders them at all times in position for the varying heights of standard phonograms, which latter will yield about twenty five surfaces. ### When these instruments are placed in business offices, a clerk or office boy will shave off the phonogram and keep a supply ready for use in the drawers of the phonograph cabinet. The businessman has only to slip one of these on the machine, close the swinging [unclear], throw up the clamp, drop the spectacle and go ahead. All adjustments are eliminated and the spectacle can be dropped anywhere on the phonogram surface—near either end or in the middle, with equally good results. ### I have also designed a water motor, which works to perfection, and which I believe will be adopted universally in place of batteries. It runs on ordinary city pressure. At ordinary water rates, the cost of operating this motor will not exceed three and a half cents per day. I have only completed one of these machines, and I have sent you photographs of the same. We are going to get our factory in shape to substitute them for the instruments we are at present making. They can be run by water power or by an electric motor; also by foot power. ### The North American Phonograph Company will very shortly discard the graphophone and furnish phonographs exclusively to its licensee companies. They having adopted [reason?] to that effect. Very truly yours, [signed] TAE [PS 1 gallon every 4 minutes 15 gallons hour price 15 c per 1000 gallons. E]

Author

Edison, Thomas Alva

Recipient

Gouraud, George Edward

Mentioned

North American Phonograph Co

Date

1889-11-08

Type

Letter

Subject

Cylinder phonograph

Cylinder recordings

Folder ID

LB033-F

Microfilm ID

139:896

Document ID

LB033484

URL

https://edisondigital.rutgers.edu/document/LB033484

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 139

License

CC0 1.0 Universal

Item sets

[LB033-F] LB-033 (Oct-Nov 1889)