Publication: Electrical World
New York, NY, United States
To the Editor of The Electrical World :
SIR: Mr. Philip Atkinson, in his article on Insulators, in your issue of March 15, says: "Compounds of asphaltum and marble dust, and shellac and marble dust, have high insulating qualities, and do not easily collect moisture on the surface; but they are hard and brittle, like glass and porcelain, and hence unfit for lathe work."
Mr. Atkinson could not have investigated this subject closely, or he would have been more precise in his statement. "What he says regarding these compounds which are exclusively used by the Chicago Insulating Company is true, except the last statement, that it is "unfit for lathe work." This material has been worked on an ordinary lathe with hard steel tools, and no particular difficulty was experienced in working it. With special tools, or with emery wheels, there is no difficulty in working it into any desired shape. The high insulating qualities of these compounds make them specially desirable.
F. S. BASSETT, Sec'y,
The Chicago Insulating Co.
CHICACO, ILL., March 25.
|Keywords:||Chicago Insulating Company|
|Date completed:||May 2, 2009 by: Bob Stahr;|