thomas edison > a lifetime of invention : inventing the incandescent lamp
thomas edison > inventing the incandescent lamp : edison begins work on incandescent lamp, 1877


Secretary E.M. Barton Writes Edison

On August 31, 1877, the secretary of the Western Electric Manufacturing Company of Chicago, IL wrote a letter to Edison at Menlo Park, NJ, that stresses the important role power generation played in the practicality of the electric light as well as revealing the competition among innovators of electricity to be the first to invent the “candle that will not consume.” 

Dear Sir,

Speaking of magneto machines, I find that the Franklin Institute of Philadelphia has recently got from Cleveland one of Brush’s machines.  They call it a 5000 Candle Machine.  It takes from two to ten horsepower to run it according to the amount of mechanical resistance that is produced.  Their price for the machine is $750.00.  The Washington University, of St. Louis, has just got a 1000 candle machine of the same sort, price $450.00.  It takes about three horsepower for 1200 revolutions, to give what they call a 1000 candle light.  Weight about 200 pounds.  Stockley, on his return from setting a new regulator for carbons, and proposes to invent a candle that will not consume.  This “candle that will not consume” is the thing required.  Dr. Herz and S.O. Field of the New California Electric Works, successors to the Elec. Con. & M. Co., of San Francisco, are on their way to Europe to get the Jablochkoff candle.  There is a great demand for apparatus for the electric light and it is one of the best things out to get the best.  For lighting mines, etc., it is of great value, and when you get so you can light the streets of a city you have something worth while.   Let us send you one of the Brush machines. Go over and look at the one in Philadelphia, and get a machine and invent your candle.  We can get something off from the prices given for the machines. 

Yours truly, E.M. Barton, Secretary.

The Brush Dynamo

This Brush dynamo was the invention of Charles Francis Brush (1849-1929) an innovator of the first important commercial product of the fledgling electrical industry in the 1870’s, the arc light.  He believed that if he could make improvements to the basic elements of arc lighting including the dynamo, carbon rods, and the rod feeding mechanism, he could displace gas as a means of lighting.  Brush constructed his second hand-built dynamo and demonstrated the development to his employer and sponsor, George W. Stockley, the manager and vice president of the Cleveland Telegraph Supply Company.  Stockley was impressed with Brush’s work and by 1876 the Cleveland Telegraph Supply Company was the exclusive outlet for all of Brush’s inventions.  Well publicized tests at the Franklin Institute during 1877 demonstrated that the Brush arc light dynamo was the most desirable dynamo at that time.

Sources: Western Electric Manf. Co. Secretary E.M. Barton Writes Edison, Schenectady Museum Archive Historical File 16-3.

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