Dear Elton,

I have a sim U-632 with the following blue underglaze ink marking. What do all the numbers represent?

PINCO 75
223  R
5230

I also have a U-660 and another style with the following blue underglaze ink markings:

Do the dots around the year represent any importance and are the insulators made by McGraw-Edison?

I have another insulator that was purchased in Canada which I cannot find a similar U-number, so I have enclosed a shadow profile drawing. It has standard U.S. threads with a clear Ohio Brass marking and a plain brown glaze. Should this be assigned a new U-number?
Scott Janz, NIA #2969

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Dear Scott,

Most of the story on the Pinco marking can be found in Jack Tod's 2nd edition book Porcelain Insulators -- Guide Book for Collectors on page 109. The year of manufacture was 1975, "223" is the catalog number and "R" represents a radio treated unit. I do not know the meaning of the number "5230".

I wrote to McGraw-Edison and they confirmed that the "ME" marking is indeed their current marking on pin types. The dots associated with the year of manufacture represent quarters ofthe year as follows:

If the "ME" is above the year, it was made on the first shift and under the year on the second shift.

Finally, an "S" following the year represents a high strength radio glaze on the top of the insulator.

The O-B insulator that you described is a new reported style for Ohio Brass. It can be found in Marilyn Albers and Jack Tod's book Worldwide Porcelain Insulators as U-2571.

Marilyn says this style is found in Canada without markings and sometimes has a powder blue glaze. We will report your find here since it is of U.S. manufacture. O-B did produce insulators for foreign sale as did Locke with their manufacture of "European Type" insulators. We do have an O-B drawing from 1908 of a "Cuban Type".

Elton

Dear Elton,

I have been collecting porcelain for about six months and I recently bought a threadless porcelain insulator at an antique shop. I paid $8.00 for the thing and would like to know if it is old. The pinhole has a diameter of 3/4 inches. I am enclosing two photos (shown on the following page).

I also picked up a U-746 with a metallic tan glaze and a mottled brown U-474 with the marking N.E.P. The U-746 has a blurred incuse marking that looks like an Imperial marking.

Another curiosity is a clamp type insulator from patent number 1,240,330. Each half of the insulator is marked "Patented E 9/18/17" and the metal clamp is marked with an "E" and the following:

Ed Sewall
Providence, R.I.

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Dear Ed,

You have found the bargain of the year! Your old threadless is U-974 and was reported back in 1972 with a second one reported in Gerald Brown's 3rd edition book Collectible Porcelain Insulators. This is an exceedingly rare insulator and possibly only the third one known. Nothing is known about these except they were found in your area with one being dug near Rome, N.Y. from a dump along a railroad track. They probably date to the mid 1800's. I would guess that you could get 50 to 60 times what you paid.

The U-746 would be a good item if you could definitely make out some of the Imperial marking through the thick brown glaze. The brown Imperials date from late 1901 to 1904.

The U-474 N.E.P is a rare marking found only on that style. The marking is still unattributed but is suspected as being New England Power Co.

The clamp type insulator is a wire holder. These odd insulator types are not widely collectable but an interesting collection can be put together showing examples of many of the unusual insulator patents.

Elton

Dear Elton,

I found two huge fogbowl insulators with triple-petticoats that were made by Ohio Brass (see marking at right) . They are much larger than any in Jack Tod's U-number style chart, so I have enclosed a shadow profile drawing for possible assignment of a new U-number. Note that it has a 1-3/8 inch zinc thimble cemented in the pin hole.
Fred Collier, jr., NIA #2933

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Dear Fred,

Thanks for the new report. Jack has assigned these U-861. 

Elton