Research Division

Reprinted from "INSULATORS - Crown Jewels of the Wire", December 1973, page 31

Dear Mrs. Harned,

My husband and I recently acquired an insulator which we believe to be a companion to Chambers C.D. 432. It is identical to the one described by Milholland, except ours shows the following embossing on the crown opposite the side with the vertical groove: PATENT / DEC. 19, 1871

Milholland says the companion has no embossing.

Can you shed any light on the value placed on our insulator?

Also, is there any new pricing information on an old Hemingray No. 2 (C.D. 132) embossed with a 2 on one side and PATENT / DEC. 19, 1871 on the other?

Thank you for your great magazine. We've met some wonderful people through your ads. 
Sincerely, 
Mrs. John McDougald 
4592 Andorra Drive 
North Olmsted, OH 44070

Dear Dora,

I wonder if any of your readers have ever heard of this one. I found a Hemingray 10 C.D. 115 clear smooth base. The embossing is perfect and says HEMINGRAY-16 MADE IN USA on the back.

Also while in Sweden this summer I found a lot of white porcelain insulators, Terrill's book, page 70, left side. Did not see any glass except the large French green sombrero.
Sincerely, 
Herb Barker 
2326 Livingston 
Missoula, MT 59801

Dear Dora:

I may not be current on glass insulator research, but I believe collectors are still wondering why the CD158.9 Boston has the "screw top". I recently ran on to a patent which evidently covers this design.

This is Patent No. 490,560, Jan 24, 1893 by Autuste J. Hauty, Saltsburg, Pa., assignor of 1/3 to John Burke, same city.

The idea is that the insulator is placed on the peg and the cap is placed on the insulator top with the line conductor positioned in the cap slot. The insulator is then turned down onto the peg, and simultaneously the cap screws down to firmly hold the line wire. For this to work, the top set of threads have to be lefthand as opposed to the righthand threads on the pin hole portion.

I have speculated in my sketch at the right what the cap may have looked like, and I assume it must have been wooden to work well and to reduce the chance for breakage that would be caused by a glass-to-glass thread.

As with most other glass and porcelain "no-tie-wire" brainstorms, the insulator is also provided with a normal side groove. Also as with other such designs, I doubt that the design was very reliable in permanently holding the line wire, and the caps were probably soon discarded in favor of using the insulator in conventional fashion. It would be a real victory if someone located one of the caps for this insulator, but the chances for that would appear to be very remote.

Another insulator design with top external threads was reported on page 26 of the June 1971 Crown Jewels, and it could also fit this patent if the top threads are lefthand as on the Boston (the correspondent didn't say).

Jack H. Tod 
Phoenix

Dear Dora:

Referring to October issue, page 18, I "JIST" happened to have what this boy was looking for. I have sent Glenn Polasik this dope direct, and so here it is for you (See following page.). This is a page (reduced one third) from my forthcoming book on UNIQUE INSULATORS.

As you will see from the copy, my specimen does not have the patent date on it and so was doubly glad to get this new information.

Have just made a display of all the STANDARD knobs that I have. It is real interesting.

Gerald Brown 
Two Buttes, CO 81084