Smoke,
Regarding glass insulators, try Jack H. Tod, Insulator Patents, 1880-1960. He
can be reached at 3427 N. 47th Place, Phoenix, AZ 85018. My copy was printed
in 1985 by the author. I think he has other volumes, but I do not recall.
This is really an amazing book that I recommend to everyone on the net.
He has references for 3,000 patents and detailed file cards on 695 patents.
The file cards have sketches that will enable easy identification.
Ron May c/o
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cc: my address will change in October, stay tuned....