[D8724AAG], Letter from John Clark to Thomas Alva Edison, August 26th, 1887


View document with UniversalViewer   → View document on Archive.org  → Re-use this digital object via a IIIF manifest


[D8724AAG], Letter from John Clark to Thomas Alva Edison, August 26th, 1887

Editor's Notes

"I notice in the Cincinnati Enquirer that you were giving you attention to the development of electricity from burning coal. ## About 20 odd years ago I invented an electro-Magnetic Motor, which cost me several hundred dollars, and which I took to New York to have patented. While there I met with and old Frenchman who also had invented an Electro-Magnetic motor on which he had spent some thousands of dollards. This Frenchman convinced me that a Motor run by electricity could never compete with steam, on account of the high cost of electricity. Even in the case of a Dynamo run by a steam engine the percentage of loss is heavy, as the steam engine (even the best) does not develop more than 10 per cent of the theoretical value of the coal. So, I laid aside my machine as useless until some fortunate inventor should discover a cheap way of getting electricity. When I saw your name mentioned in that direction I concluded to keep the cause along, even at the risk of being considered a crank, intruder or what not. And therefore I offer a few suggestions regarding improvements in the Thermo-Electric Battery. 1st -- As the heat ascends, let the junctions be heated at the upper end, the battery being supposed to be perpendicular -- 2nd Let the junctions be large that the current may pass freely 3rd -- let the plates of Bismuth and Antimony or whatever is substituted for them, not extend beyond the poitns of junction where the heat is applied -- connections to be made by iron or other cheap conductor. I have several other suggestions which I would like you to carry out directly for your benefit and indirectly for mine. I said long ago if any one could perfect the Thermo-Electric Battery it would be Eidson -- and I hope you succeed." Marginalia by TAE: "The principle is not thermoelectric which I use. The Apparatus is based on the heating & cooling of iton to increase and diminish its magnetism & thus throw current into coils of wire in proximity --"





Folder/Volume ID


Microfilm ID


Document ID



Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
Download CSV | JSON