The Thomas A. Edison Papers Digital Edition

Transcription

Berlin
[Brother St.?]
22 June 9 1902
c/o Dr L Sele

[Marginalia: file]

Mr Thos. A. Edison
Orange, N. J.

Dear Sir:

When returning from London on Monday last I found that the best cell had arrived and I immediately started my work with same. In purifying the potash I proceeded in the way used in the Laboratory, about a year ago and I succeeded in preparing a pretty pure solution.
It would have been better if there had been sent a complete, sealed cell, for I think the office will demand some kind of an endurance test, of at least some ten discharges.
In that purpose I have procured a larger glass jar, where the whole cell may be airtight, enclosed, in order to keep the carbonic acid out.
Having had no information about the
<file> development of the battery since December last, and since no instructions were sent along with the test cell, I really do not know what to expect of the cell, and what capacity of some would suffice for handling it one for be tested by Prof. Foerster.
The test cell contained 1 nickel plate and five iron plates. This arrangement is the reverse of what I expected – and of the arrangement in use one year ago; I therefore thought it well to cable you: "Should cell contain one nickel [illegible overstruck handwriting] iron." Hereto I received as answer your cable: Present cell contains equal numbers nickels "and irons." If there exist no special reason for having an excess of iron in the cell, I should think said arrangement would give rather unfavorable results as regards capacity per unit weight, for which reason I intend to put together a cell of all 9 plates received.
I do not know whether the plates are apt to depreciate during shipment, anyhow, as for the results of the discharges have not been very good:
1) Cell of 1 nickel and 2 irons discharged at a rate of 36 amps or 150 milli amperes per nickel. pocket. Capacity: 14.4 [illegible] Hours above .5 volts or 600 milli amp hours per nickel pocket
2) At a rate of 166 milliamp per nickel pocket (4 amp) Capacity: 12 Amp Hours above 1 Volt or 500 milliamp hours per nickel pocket
3) After long charge at a rate of 150 m/a per nickel pocket. Capacity: 19.8 Amps Hours or 805 milliamp hours per nickel pocket above .5V This, I presume, is too low a capacity [to] show the superiority demonstrated by the problem office; I am therefore testing all of the loose plates, sent along with the cell, and I feel confident there are better ones among them.
When I have furnished the preliminary testing I shall cable you the result and ask you to decide, whether the results suffice for the official test.
I am expected to be in Dresden in two days by which time I hope to have finished the test.
Mr Bergmann showed me today a letter, from a certain Mr W N. Stewart, who writes about your battery patent. Mr Bergmann is going to send you the letter. Where Mr Stewart got his information about the patents I do not know – maybe from Jungner's people. I have the sensation that Jungner is not going to try once more to interfere with your patent in England.
As for Germany, Faures patent suffices entirely to make Jungner noninjurious, and the obstacles we have had here have been something quite different from Jungner patents. In Austria, I understand, a patent will soon follow, as soon as the corresponding patent is granted in Germany.
Mr Dick showed me some time ago another letter from Mr Stewart, about Cadmium mines. I am surprised that a man who is in possession of such precious ideas and valuable information has to ask for a ticket to Berlin.
 I have read with interest, in the papers as well as in a letter from Mr Dick for Mr Bergmann, that you have constructed batteries to drive automobils for a distance of more than 60 miles on rough road. The fact awoke quite some surprise here; for the litterature, by German electrochemists, on your battery, has to a great extent robbed people of their confidence in the battery (for example Dr. Peters' articles)
Yours very respectfully
Rob. Rafn.