[D8737AAG], Test Report, John Kruesi, Charles Batchelor, February 15th, 1887


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[D8737AAG], Test Report, John Kruesi, Charles Batchelor, February 15th, 1887

Editor's Notes

"The discs of the experimental #12 armature have been counted and weighed with the following results: There are 1,061 plates on the armature (1,050 was the calculated number). They were divided into three lots, two of 525 discs each and one lot of only 11. The two lots of 525 each weighed exactly the same -- 97.5 lbs (not 1/4 lb. more or less), and the whole number of plates weighed 197 lbs.. The weight of a solid core of same length, and of the pattern (cross section) of a single plate, allowing for all holes, is 244 lbs. Therefore the percentage of plates to effective length is 80.7 Calculating back from this, we get .0126" as the average thickness of each plate. Since there are 11 sheets of paper to 5 of iron (the paper measuring .0011" diam.), one set of five discs and papers to match would measure .075", but the actual space taken is .0783". There is therefore 5% waste of space only due to springing of the iron, or .0006" spring for each plate."





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