Research Division

Reprinted from "INSULATORS - Crown Jewels of the Wire", September 1982, page 18

Dear Dora, 

Here's something new in both AMERICAN and WHITALL TATUM. I recently purchased the following insulators:

(The AMERICAN also has a large, milky blob in it. (I assume these are "new", since they are not listed in Milhollands books.))

When I first heard about your magazine, I thought it was great that insulator collectors had their own magazine. I still do; and we're lucky it's such a good one, too! 
Jim Brogle, NIA #2706

Dear Dora,

I recently found a blue Lynchburg #36 (CD 162) with sharp drips. As you know, this is quite a common insulator.

A closer examination showed it to be quite uncommon. It had a couple of very strange ghost embossings. The first one was right above the name Lynchburg. It said New York. Reading this, I reasoned that the back would say Brookfield. What I found on the back gave me quite a surprise. Just above the word Made were the initials H.G.Co.

I can see how it would be logical for it to say New York, because Brookfield could have sold the mold when they closed in 1922; and since Lynchburg started in 1923, they could conceivably have bought it. But I don't see how Hemingray fits into all this. Could Hemingray have sold this mold to Brookfield?

I would appreciate any answers from anyone out there.
Happy Hunting, 
John Gozzi, NIA #2654

Dear Dora, 

An interesting aberration of a CD 155 Whitall Tatum No. 1, S.B., is now in my collection. It's dark amber. You might check your books to see if any of these have been listed -- my references did not show such an item.

The explanation is that a relative who is a scientist suggested irradiating an insulator to change its color, so I gave him a clear CD 155. Two megarads of gamma rays turned it dark amber and left no harmful radiation. He suggested that its color could be lightened by placing it in an oven at 250 degrees for a while and allowing it to cool.

I thought that our readers should be made aware of this item (1) as a curiosity and (2) more importantly, that insulator color changes can be effected in this manner. Naturally, no marks of any kind were left on the glass.

If any more of my glass receives this "treatment", I'll advise you of the results. Now, if we could arrange to produce some cobalt blues ....... 

"CJ" continues to be an enjoyable publication. Your efforts and those of the contributors are appreciated. The historical articles that appear are fascinating, and the arrival of each issue is eagerly anticipated.
Cordially, 
Guy P. Seeley, Jr. NIA #1910 

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Editor's note: 

See reprint below from April 1972 issue of Crown Jewels. 

COBALT-60 IRRADIATION

I told you some time ago that I would write you about my experiments with 'Cobalt-60 Irradiation of Insulators. I've had mixed emotions about the whole thing because of the fact that the radiation does change the color of some types of glass; and, although I have stressed the fact that the ones I've traded have been artificially colored and are FAKES, I know of at least one and maybe two that have been traded off with no mention of the facts behind the color. A couple of ads that have appeared lately sound as if someone else might have access to an irradiator, too, but then again the colors being offered might be true. I certainly don't want to hurt someone's chances at some good trades, but neither do I want people trading high for something that is common but artificially colored.

Anyhow, Cobalt-60 radiation, which is used in the treatment of cancer and in research and industry to promote chemical reactions, is exactly the same as high powered X-rays. These rays react with some types of glass to change its color. Even though the radiation comes from a radioactive isotope, the material being irradiated does not become radioactive, so there is no danger in handling these pieces. 

I haven't tried all types of glass, but I do know that PYREX comes out a beautiful dark tea color. Clear glass, like the common Hemingrays, also turns sort of an amber. 7-Up green Hemis come out almost black; while the plain old aquas, both Brookfield and Hemis that I've tried, really don't change much, maybe from the aqua to more of a gray green. Of course the intensity of color produced is related to the length of time in the irradiator: the longer, the stronger. The process is reversible. If the irradiated glass is heated or left in the sunlight, it tends to fade. I know that heating laboratory Pyrex glassware in a bunson burner flame will clear away the color completely, but I haven't done any precise testing to tell just exactly the temperature required. Unfortunately, my laboratory no longer has the irradiator, and I can't produce any more Fakes. Maybe that's good. I've used them mainly as mementos (mainly HEMINGRAY-14, CD 160) of visits with other collectors, but have traded some PYREX, CD 128 and saw one at Colorado Springs meet last summer that the owner swore was a true color; but I knew it was one of mine because I recognized the exact embossing, even to the imperfections in it. Soooo, let the buyer or trader beware. 

Dennis McHenry