[D8369ZAC], Letter from Thomas Alva Edison to John F Ott, 1883
https://edisondigital.rutgers.edu/document/D8369ZAC
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Title
[D8369ZAC], Letter from Thomas Alva Edison to John F Ott, 1883
Editor's Notes
[potentially useful; can we figure out date for this?] "We have great trouble with the commutators of all our machines. The bars get high or low & thus make great sparking. The mica being built up with shellac when the commutator gets hot it contracts & expands and gets bad. I have made a slate cylinder on which the bars rests but it split. You know Bergmann moulds the safety plugs by using oxide magnesia & chloride magnesia & mixes 50 pct of other stuff. You will remember Conant tried a number of experiments which are recorded in book you have. The pure stuff without any mixture set as hard as stone so please go ahead and see if you can mould large pieces, say a shell. Go down to Soldan & get the exact size of the shell & thickness he will allow also the bevelled end piece(?) & try and mould them in a plaster of paris mould or otherwise. [several sketches] You see I want to displace the mica entirely on ends & bottom of bars but not between as the mica works all right between bars. Edison." [dynamo]
Author
Recipient
Mentioned
Date
1883-00-00
Type
Folder/Volume ID
D8369-F
Microfilm ID
70:902
Document ID
D8369ZAC
Publisher
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University