1979 >> May >> Questions Answered by N. R. Woodward  

Questions Answered by N. R. Woodward
Author of The Glass Insulator in America and originator of C.D. #'s (Consolidated Design Numbers)

Reprinted from "INSULATORS - Crown Jewels of the Wire", May 1979, page 13

Allen Klapaska, Hydes, Maryland, writes: I have come across an unusual CD 102. It is a Brookfield New York. As far as I know, the CD 102's come in 2 & 3 piece molds. But I have one with a 4 piece mold, and I have never seen or heard of any. At the left is a drawing of the CD 102 I found on an old barn while on an insulator hunt. I would like to know if anyone can tell me if this is a rare CD 102 Brookfield.

Thank you. 

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In reply to Allen Klapaska:. Since the Brookfield ponies were made by the millions and over a period of about 40 years, there is an endless variety in the molds used. They were not always machined in the same way; and I suspect that rather than a four-piece mold, you have an insulator made in a two-piece mold in which the groove that formed the lower wire groove lip was machined with a sharp tool that made it appear that the mold parts separated there. Otherwise it would have been necessary to separate the mold four ways, in order to remove the insulator, and that would be a needless operation for so small an insulator. 

Of more interest is the fact that you have a pony skirt-embossed BROOKFIELD/ NEW YORK, with the mold line across the crown. That is a later embossing, and most of them are "three-piece mold" products. About the time your insulator would have been made, one of the patent drawings for one of their semi-automatic presses shows a two-piece mold. Perhaps that is its origin. 


From Donley Hostutler, Dover, Ohio: I have two insulators that I cannot find in Milholland's books. One is a CD 162. The front skirt has: W BROOKFIELD; the back: NEW YORK. Smooth base, purple. 

The other insulator is a CD 116. Crown side is embossed: PATENT DEC 19 1871. Below on skirt there are two round flat spots. 

Back skirt: JULY 1st 1882 
  PAT APPLIED FOR 

Smooth base, aqua. 

What can you tell me about these insulators and their value? Thank you for any help you can give me.

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In reply to Donley Hostutler; You have described two very fine insulators! There aren't very many of any style of Brookfields in purple, but most of them are of the earlier, crown-embossed ones. Your CD #162 is probably late Brooklyn production, when most of them were light green. 

The CD #116 is even more interesting. None of this style is plentiful; but a scattering of the later ones which are embossed as yours, but with the PATENT MAY 2 1893 on the opposite skirt half-mold, and drip points, have appeared in several parts of the country. These are, at best, a unique find. When all three dates are there, they span a period of nearly 22 years. The only illustration of this particular insulator (with drips) that I've found is in the 1901 Western Electric catalog. And that's almost 20 years after the 1882 date which is in itself a mystery. Its implications are not understood. 

Yet with all the spread of dates, the CD #116 remains a scarce and very desirable item. And yours, with the smooth base rim, is that much more exciting. Thanks for sharing it with us. 


Jack Gooden, Jr., Medford. New York, says: I would like to know how much the telegraph insulator on the left is worth and around what date it was made. It is aqua, VVNM. Back:

CAUVET'S 
PAT 
July 25 1865 
Pat Jan 25 1870 
Pat Feb 22 1870 

I also have in my possession another Brookfield telegraph insulator (see sketch). The name Brookfield is misspelled, with the letter "E" missing. This insulator is also aqua, VNM. Back: 

PAT 
JAN 25 1870 

I would like to know around when it was made and its value.

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In reply to Jack Gooden, Jr.: Your two CD #133 Brookfields are of the style that was most common in their time; therefore, even though they are old, they are not rare. The 55 FULTON ST. address covers the period approximately 1868 to 1882; and the 45 CLIFF ST. address followed, to 1890. It is presumed that the letters E.R. are for Erie Railway. The Erie, now a part of Conrail, was one of the earliest lines, with a main line from an eastern terminal at Hoboken, New Jersey, stretching west to Chicago, as well as several secondary main lines and branches. 

The error in spelling on the later insulator was probably in one mold only, therefore would be considered rare. Errors of that sort on the older Brookfields are very common; but any one specific error such as yours would, in itself, be difficult to locate. 


William C. Ogden, Virginia, Minnesota, writes: I have a few questions. Most of my C.D. 121 Hemingrays have this embossing: F--HEMINGRAY; B--Patent/May 2 1893. But a few have this: F--Hemingray; B--No 16. Are these considered to be two different insulators? I also have a dark blue Hemingray 16 (C.D. 122) with sharp drips. Are these rare? 

Are any of these Hemingray 42's comparatively rare: a clear, tall-skirted one; a straw colored, with short skirt; a dark blue with sharp drips; and a dark blue-black with both sharp drips and a dome top numeral? 

What was the purpose of the Hemingray D990? Was it intended for a low voltage distribution line or a telephone or telegraph line? 

I have several clear Hemingray 512's a 512; a D512 (LOWEX); and a D512 (LOWEX) with copper pin hole liner. What was the difference between the 512 and the D512? What did LOWEX mean? What was the purpose of the copper pin hole liner? 

I have the R3 and R4 Continental rubber insulators with several different embossings. Most have the R3 or R4 on top of the dome; however, I have a few that have BS3 or BS4 instead of the R. Any idea of what this means? 

Any help that you may give me on these questions will be much appreciated. Thanks very much. 

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In reply to William C. Ogden: It's interesting that you say the CD #121 embossed HEMINGRAY/ PATENT MAY 2 1893 are more plentiful in your area. In most places, the later HEMINGRAY/No. 16 would be more common. They are the same style insulator, but with different embossing and made during different periods. Also during the same time Hemingray made many with smooth base rim lettered AM. TEL. & TEL. CO. Ones embossed HEMINGRAY/ No. 16 date to World War I period and the years immediately before. 

The change in style from CD #121 to 122 was around 1921. The ones with the sharp drip points were first and were made for two or three years. None of these is rare, since they were made by the millions; but if you can find one of those sharp-drip kind that is absolutely mint, all points intact, you're lucky! 

In Hemingray-42, about the only ones a collector will buy are the famed and mysterious "MR", and the aqua one with smooth base rim. Otherwise, there are those with certain minor variations that are scarce; but they are not such as have attracted the attention of collectors at this time. 

As with the CD #122, the change from CD #152 to 154 occurred about 1921; and the ones with the 42 sharp drip points, some of which have the shop number 1 on top, are first. The change from dark to light aqua occurred in 1931, and the short skirt appeared ten years later, 1941. In 1948 a final variation came along, small like the ones with short skirt, but proportioned like the earlier, large ones. 

And while we are on the subject --- PLEASE. Everybody out there! If you inquire about later insulators of any kind that have mold and date codes on them, including an exact copy of them, with dots, helps me give a more meaningful reply in many cases! 

Now about the D series. D is for distribution. The D numbers were offered over the period approximately 1930 to 1950. D-990 was the smallest, intended for the secondary lines from the transformer to the drop lines to buildings. That would be the 120-240 volt range. D-990 would be a lousy communication insulator due to almost no protected inner skirt, and I doubt if any were sold for that application. D-512 and 512 are the same style, and why the D was dropped from the LOWEX and later molds I have no idea. 

The two enclosed Electrical West magazine advertisements, from 1931 and 1935, respectively, refer to the D series. The later one features the brass bushings which were also a short-lived venture. 

LOWEX was Hemingray's answer to Corning's PYREX. LOWEX was for Low Expansion, and referred to the glass formula similar to that of Pyrex which was supposed to obviate thermal cracking. In actual practice, though, neither of these glasses stood up as well as regular soda-lime bottle glass, properly annealed, and were not offered for very long.



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