We last published an updated list of the known Pittsburg date control markings in the April 1987 issue of CJ. Many new reports have been made and the mystery of the date codes still persists. While we may never solve the mystery, it is still interesting to follow and to see how many different markings can be located. There must be many, many others that have not been reported, so please check your collection and drop me a post card of any new ones. Many of you are interested in these Pittsburg markings and the variations appear endless. The revised list of all reported markings is shown at the end of this article.

I found a new one:

NOV 29 Ans'd.

Chris Hedges reported several full date markings and one date code:

JUN 8 1917
JAN 12 1921
JUN 27 A.M. (U-672)

Scott Janz has reported several new markings in the past and he has come up with yet another:

MAR 11 Rec'd

Mike Guthrie has several of the new style, U-577, with three new markings all just a few days apart:

JUN 6 1915 (Sun)
JUN 7 1915 (Mon)
JUN 11 1915 (Thu)

Note that the plant was operated on Sunday. We need more groups of dates to help us to understand the puzzle.

On a recent visit with Lu Farin in north Texas to see her fantastic collection of both glass and porcelain, I found several new Pittsburg markings. By the way, Lu also has a great collection of multipart porcelain insulators, porcelain uniparts of all types as well as other collections so beautifully displayed such as pitchers and her husband's collection of rocks and shells. I thoroughly enjoyed her hospitality during the 24 hour insulator marathon and found several new styles of multiparts for my new book.

The new Pittsburg markings in Lu's collection were as follows (note the first reported 1914 date):

APR 28 1913
MAR 3 1914
MAR 15 1915
MAR 29 1915
JUN 19 1917
FEB 21 1921

Lu had a very interesting piece which is the bottom shell of a multipart (see photos on next page). Very clearly incuse marked on the top of the shell above the pin hole in the unglazed area was the full date stamp: JUN 19 1917. No, I would not recommend busting out the cement of your multipart Pittsburgs to check for dates, but it is nice to know that Pittsburg probably marked many of their multipart shells this way rather than on the glazed area. The date control stamps could have been for their own use at the factory and the exact purpose is open to speculation. How about the following guess?

Stamping the unglazed areas would be easier to stamp and read. All the parts for a particularly large order could be tracked using the full date stamps knowing the production schedule for that order. Perhaps, too, using that same logic, the date control markings (AM, PM, Ans'd, Rec'd and PAID) could have been used to identify other orders (as many as six orders in production at one time during peak periods) with the month and day to help track the production.

However, the inclusion of the year in the full date markings may indicate that the multipart shells and completed unipart insulators carrying these markings were standard "shelf" items. Various standard styles or shell parts could have been in inventory (from a planned inventory or excess production runs from a particular order). The marked shells of multiparts may have been interchangeable with one or more styles and would help in using the older insulators and shell parts first.

Another example of the marking of shells was found in Lu's collection where one multipart had the full date marking, MAR 3 1914, on the lower inside surface of the intermediate shell in the glazed area. These markings can be difficult to find and read giving the small space between the assembled shells. It seems that the dating may have been more important in accounting of individual shell parts rather than the completed multipart unit.

Greg Hale sent these nice drawings (below) of a Pittsburg fuse cutout that he and his wife found at a barn sale. Wire fuses were used on the knife insert and the unit was mounted on a utility pole using the two large holes.

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