[D8801AAP], Letter from Derick H Fitch to Ezra Torrance Gilliland, June 19th, 1888


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


[D8801AAP], Letter from Derick H Fitch to Ezra Torrance Gilliland, June 19th, 1888

Editor's Notes

"Your favor of the 18th [unclear] noted. I understand Mr. Edison desires 2 1/2 Volts and 2 Amperes, from which I infer that his Motor Mill have 14 Ohms. 2/5/1/25= 2 Amperes. The internal resistance of the battery being practically O. the E.M.F. we can fit it very closely, two of my cells having a little more than 2 1/2 volts; but primary battery is as you know a pretty hard service, yet I think we can do it satisfactority cleanly and cheaply, though it will regain cells [unclear] several plates of large surface. I enclose a diagram representing two such cells in glass jars 4 1/2" wide, 7 1/2" long, 8 1/4" high, each containing 3 carbon plates 9" X 6"X1/2" and two zinc plates 9" X 5" X 1/4" the plates in each cell connected in duplicate and the cells connected in series as represented in the diagram. I think these cells would do the work, as the internal resistance would be only a very small fraction of an ohm. Nearly 0, though possibly, test might show the need of one or two additional plates in each cell. Thus for me have had no call for this class of service, hence have no material on hand adapted to it but very likely Mr. Edison has cells very nearly corresponding to these in size and construction which might answer for trial. IF so I will send what excitant is designed for trial. If not, and you desire, I will make and furnish the cells for this purpose at Net Cast. Or possibly they could be made cheaper at his laboratory. My excitant requires a carbon specifically adapted to it. Many of the plates found in the Market do not work well with it." Respy, D.H. Fitch [Includes Illustration]




Folder/Volume ID


Microfilm ID


Document ID



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