[D8949ABS], Letter from William P Dewey to John Birkinbine, July 6th, 1889
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Title
[D8949ABS], Letter from William P Dewey to John Birkinbine, July 6th, 1889
Editor's Notes
In your article contributed at the February meeting to the "American Institute of Mining Engineers" you mention incidentally on page 16, that the "Edison Concentrator" "with a a modification" has been used in treating gold ores. ## As a fellow member of the above institute, and as an old "miner" I take the liberty of asking you where, and on what class of gold ores the concentrator was used and also if it proved successful. I know at present of but one class of so called gold ores were its use might be or advantage, I refer to the so-called "black sand mines" found on and near the sea coast of California. The fine black sand on the back and further in the interior in layers from one foot to six feet in depth, contains quite an apprciable quantity of very fine gold and a large quantity of magnetic iron. ## Some years ago I took over from France a machine called the "Extractor Varin" consiting of two bands, arranged one above the other, containing permanent magnets, and working much as the Wenstro Separator, except that the magnetic and adhering particles were swept off the barrel by a recolving brush. I worked well, but necessitated the drying of the sand, which cost too much to make the matter practical. Edison's separator is just what is needed for that, but we have many other ores which when crushed needed separating or concentrating before being treated, and as I desire to keep up with all the latest inventions or discoveries of the day in these particulars I have written this note for a little information from you as to what class or character of ores had been applied. I am temporary in Europe for the benefit of my family, and while here am looking into all that is scientific and useful, especially in the mining line.
Author
Recipient
Mentioned
Date
1889-07-06
Type
Folder/Volume ID
D8949-F
Microfilm ID
126:1031
Document ID
D8949ABS
Publisher
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University