1979 >> February >> Questions Answered by N R Woodward  

Questions Answered by N. R. Woodward
Author of The Glass Insulator in America

Reprinted from "INSULATORS - Crown Jewels of the Wire", February 1979, page 12

Jack Goodew, Jr., Medford, N.Y. writes: 

I would like to know if you have any information on the type of insulator shown here. The front is embossed BROOKFIELD PAT.OCT.8-1907 There is no other embossing. Collectors and linemen that are familiar with this type say it's scarce, but they're only local friends. I would like to know what you think. I once had ten of these things and traded them away for carnival, purple, amber and blue types. I think it was a good trade. 

In reply to Jack Goodew, Jr.: 

Your Brookfield CD 150 insulator is quite a desirable item. It shows up in their 1912 catalog as their Number 42, Deep Groove, Double Petticoat, External Thread Insulator. Although not extremely old, it evidently never became a standard item with any major user; and they are scarce today! Unless the colors you traded for are very special in some way other than the color, I'm afraid the other fella got the best end of the deal. 

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From Greg & Margaret Robertson

Recently at a garage sale we purchased two CD 233's (F-Pyrex Reg.U.S.Pat. Off. B- 661/Corning Made in U.S.A.) Someone had painted them a transparent red. We bought them knowing they were painted. We used lacquer thinner to take the red paint off. Underneath it was clear. Milholland's book doesn't have them listed in clear, just carnival and yellow. Could the yellow have come off with the red paint, or were they made in clear also? If so, how much would it be worth? Before we cleaned one you could scratch it and see yellow underneath. We have one still painted red. 

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In reply to Greg & Margaret Robertson: 

Most of the Corning insulators were made of glass that is essentially clear, but has a varying degree of yellow tint. The thickness of the glass and the particular light source when viewing make them look more or less yellow. I would think that your specimens are probably the usual ones which are in fact nearly clear. The color of the glass could not be changed by the cleaning process you describe. When you first scraped the red paint, your impression of yellow color came from refracted light from the paint job, which would make a true evaluation of the glass color impossible. 


Mark Zamboni, Pittsburgh, Pa., writes: 

A few months ago I went to a local show and picked up a CD 193 A. T. & T. CO., light aqua, NM-. So far I have not been able to find a price for this, and I can't find it in Milholland's book. I was hoping you could help me with this insulator, finding a price and telling me whether it is common or not. P.S. I bought it for a quarter. Thanks for your time. 

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In reply to Mark Zamboni: 

Your A. T. & T. Co. transposition top is a CD 191, rather than 193. It shows up in Line 2582, Milholland-Keating price list. A real buy for $.25 though 


From Rick Herrera, Fort Worth, Tex.: 

Recently at a flea market I got an aqua Brookfield CD 121, S.D.P., with Brookfield on the front and this on the back and wondered if anyone could tell me why this marking on the back. 

Could it cover another embossing? These are raised above the glass. 

Secondly, I have a CD 152 , It. blue, with no embossing except NO 48. On the top is this marking. 

I wonder if you could tell me what this means. I have others that have numbers on their tops. 

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In reply to Rick Herrera: 

The engraving in your CD 121 molds was originally A.T.& T.Co. These molds were used first to make the last of the insulators marked especially for American Telephone & Telegraph Co.; then the same molds were used to make the much more numerous BROOKFIELD CD 121. The odd marks on the "back" of your insulator are where the original engraving was covered. 

The no-name No. 48 sometimes has a "1" on the crown; and I suspect that the odd pattern on yours is where the hot glass squirmed around the bottom of the mold as it fell in and tried to pick up the "1" several times. This happened quite often with older insulators and resulted in double or "shadow" markings of various configurations.


Craig Bruegger, Colona, Ill., writes: 

I have two insulators that I hope you can help me with. 

The first is a Whitall Tatum No 10. It is a very light silvery carnival glass. I wrote to Don Wentzel who was involved with a Whitall Tatum. He thinks it might have been an experimental attempt at carnival. 

The other is a glass dome with an indentation on the front. The name on the front is: THOMAS'S HALIFAX. On the back in small print is: made in england. I have no idea what it might be or what its use is. The insulator is lighter in color than the picture shows. 

I would be grateful for any information you can give me. 

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In reply to Craig Bruegger: 

Although Whitall Tatum (and Armstrong) were making insulators at the time Owens-Illinois and Corning were into the iridizing thing, insofar as I know, we have no definite knowledge that any iridized insulators were ever made at Millville. This does not prove that they weren't, though. During the period to which your insulator seems to belong, some Whitall Tatum glass was quite yellow. When this yellow glass gets buried for a time in alkaline soil, the resultant etching on the yellow glass makes a surface very similar in appearance to iridizing. Could this be what you have? 


Mike Doyle, Annandale, Va., states: 

I would like to know what years Brookfield put style numbers on their insulators, such as NO 9, NO 36 and NO 20. 

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In reply to Mike Doyle: 

While we have no definite information and probably never will, all evidence indicates that the style numbers were added to Brookfield insulators during the last few years of their manufacture. Some, such as No. 3 TRANS. were probably made earlier; but the No. 9, 36, 38 and 48, for example, tie in with the last efforts of the company, during and immediately following World War I. Also the mold numbers (appearing on the skirts and not to be confused with earlier shop numbers on the crowns) belong to the same period. 


From David Turner, Virginia Beach, Va.: 

I am writing about a CD 733 insulator that I have had for some time. It is embossed W. BROOKFIELD, 4 55 FULTON ST N.Y. On the back it says: CAUVETS PAT JULY 25 1865. Directly above the patent date are some very small numbers: 5, 1865. It appears that the whole insulator was embossed in this way and was re-stamped. I was wondering if this is unusual and also why I cannot find #4 in any books? I can find only #1 and #5. Any information you can give me as to value, age will help.

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In reply to David Turner: 

The CD 733 with shop number 4 would probably best fit the 1868-1870 period. On insulators that old, we have mostly logical deductions to rely on, since there are no written records that would answer minor detail questions.

The shop numbers had no significance after the insulator was packed for shipment, and one could only guess that not so many were made using the number 4. In my personal records I don't show a 4 in a comparable insulator made with threads, either. 

Insofar as the small figures are concerned, there were some molds during that period that were engraved with very small characters. One could only guess that the mold was re-engraved with larger characters, and the small ones were not entirely covered. The insulator itself would not have been "re-stamped", as there would be no way to do that. In cases where there is "shadow" embossing, it is the same type as the main embossing, so the above explanation would be about the only one for your most interesting specimen. 


Kenneth M. House, Casselberry, Fla., writes: 

While a friend and I were digging for bottles and insulators in Maryland, we found a dead end insulator embossed: C & P TEL Co. I have enclosed a description, and would like to know if any collectors might have it in mint for trade or sale. This insulator is medium aqua glass. Would you know of any information on it? 

P.S. Would there be a CD number assigned to this insulator? 

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In reply to Kenneth M. House: 

Your Chesapeake & Potomac Telephone Co. dead end insulator is quite unique! I've not seen this, nor any other insulator of a similar style made or embossed specifically for telephone work. If other Crown Jewels readers have, let us know about it!


From Doug Henderson

Above are two profile drawings of two CD 115 insulators. One, exhibit "B", is the ordinary CD 115, and the profile is that of a "Diamond" insulator. The other, exhibit "A", is the profile of a "No Name". 

The late Mr. Milholland showed this insulator to Mr. Woodward, and when it was returned to me both gentlemen were of the opinion that it was a CD 115, and Mr. Milholland had made a notation that it was a dandy. It is a medium dark aqua with many bubbles. As can be seen by the illustration, it is of a general CD 115 design; but the wire grooves and ridges are very different. 

I would like to know if there are many insulators similar to this one. Perhaps some of the Crown Jewels readers may have this insulator and would comment on its scarcity or commonness. 

Also, I have four Brookfield two piece transpositions, CD 191, 190, which came off a local telephone line a number of years ago, and which are different in their marking from the regular two piece transpositions. The bottoms, or CD 190, have a 6 rather than a B. 

These sixes are perfect, and not like the imperfect B's which are deformed because of imperfections in the engraving for the letters in the mold. (See tracings above.) 

Can you comment on this type of CD 190, or perhaps some fellow collector has one or has seen this variety?

Any information on the above two insulators would be appreciated.

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In reply to Doug Henderson: 

Your CD 190 with only a 6 is a stranger to me. But there is a rather typical A.T.& T. Co. CD 190 made by Brookfield that has just such a 6 as you describe to the left of the A.T.& T.Co. embossing. Check your CD 190 for possible covered engraving in the mold a little way to the right of the 6. I'm surmising that these may be the same molds with the A.T.& T.Co. removed, but the shop number left, and no other embossing substituted. 

As to the CD 115 with no embossing and rounded wire grooves: I have no idea of its origin. I've seen no others. Perhaps other readers can comment? 


Dennis E. Crossland writes: 

I need help in finding out the CD number of an insulator I have found! Please help! Skirt (F) W. BROOKFIELD, (B) NEW YORK, crown (top) I -SB- Petticoat- heavy thick glass, in order of CD 134, but wider and heavier, 4" H, 3-1/2" Base, light aqua color. Can you help me? 

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In reply to Dennis E. Crossland: 

It looks as if you have a CD 162. If it doesn't fit there, we would need a more accurate description, or to see the insulator, in order to place it properly.


Kenneth La Frenier writes from Phillipston, Mass.: 

I am sending you a picture of an insulator that I picked up at a flea market. Could you give me any information on what type it is? It measures six inches across the base, nine inches in height. It has six wire grooves on the outside. Its weight is four pounds. The color is aqua. It is crude looking and appears old to me. I would really appreciate any information you could give me. Thank you. 

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Your insulator is in reality half an insulator! It is the center of a Locke high tension line insulator from the very early 1900's. The enclosed copy of a page from the 1904 Locke catalog shows their No. 25, which is made using the center piece that you have. Also, around 1900 and possibly for some time thereafter, a porcelain top was used with this same glass center. Either way, it is Locke glass made by Brookfield. The same style as Locke No. 25 shows in the 1912 Brookfield catalog, but probably most of these were used 1900-1910. 


Large Image (135 Kb)

As you can see, the six "wire grooves" are not that at all, but are ridges to anchor the center securely when it is cemented into the top. 


From Jack Goodew, Jr., Medford, N.Y.: 

This is another specimen that I have, but no information on it. These are considered scarce around here. These were also made in clear by Corning Pyrex, but they're not worth as much. 

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In reply to Jack Goodew, Jr.: 

The Pyrex No. 441 was one of the more common of their line. We have no production or sales records on those or any of the Corning insulators; but many hundreds of them were in service in Southern California and in the Northwest, as well as in the East. All of those that I saw on the West Coast were clear, though. The enclosed page from a Corning catalog, not dated, but about 1935, shows the specifications for the 441.


Large Image (137 Kb)


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