[D8621K], Letter from Edward Hibberd Johnson to Thomas Alva Edison, November 13th, 1886


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[D8621K], Letter from Edward Hibberd Johnson to Thomas Alva Edison, November 13th, 1886

Editor's Notes

[Long, technical letter describing Johnson's findings about the Municipal System] "I begin to catch on. An Edison 3 wire station with Municipal Dynamos as the generators, 1500 volts on each side, 3000 across the A and B side." [Goes on to describe distribution and placement of converter stations, including sketch.] "If No 1 & 2 should throw their converters off (or too many on) the same side, a telephone message from the station would correct the fault. Or in other words, the balance between A & B on the mains could be better preserved than on the lamp circuits[?], even though the units would be larger." [More technical discussion of how frequent distributing stations could be to keep cost down]. ##"The Zip[?] people have to multiply their converters whereas we simply mutiple them, thus permitting larger units to be used and the employment of the requisite attendants. In fact, a converter station for 1/2 mile square would require but one man for any number of converters and feeder regulation. ##Jesus, this is a big thing you have got into now. The extra loss in your converters will be more than made up by the added economy of a River Station, saving in rental charge, etc. Whereas in Zip[?] he loses the advantage thus gained by the extraordinary lack of efficiency of his generators (alternating). There is no trouble in the matter of insluation." [Discusses why insulation is not a problem, due in part to lack of high tension wires, and in those few "insluation of very high order can be employed constant current in houses as against alternating."] ##"Absolute preservation of our present 3 wire system with all its component parts and with only the demand now made on insulation. No disturbance of our factories or standard of [---] or education of employees. Dynamo and Engine with just as now, save that Dynamos will be municipal instead of domestic. ##Size of our mains only 37 1/2% of those of Westinghouse or Zip[?] (what a staggerer). ##'Admit that you can get for 1.50 what costs us $150. We can by this new system of Edison get for 15 cents what cost you $1.50.' How would that strike his and the public ear? ##Distribution and Regulation being now perfectly worked out by us have only to be applied to this system to guarantee equal results. ##Zip or W must work out a system or steal yours. ##And more ad nauseum, ad infinitum, or any other ad you please. Do I catch on?"




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