N. R. "Woody" Woodward is the author of THE GLASS INSULATOR IN AMERICA, 1988 Report and developed the Consolidated Design Numbers identification system for glass insulators. 

The following question comes from Phil Nichols, Belvue, Kansas

QUESTION: I have four CD 152 embossed (F-S) HEMINGRAY (R-S) No 40. All four insulators have a large number on the very top of the insulator. Are these mold numbers or was there some other reason for these numbers? The numbers I have are: 4,5,7,8. I have been searching for years for numbers 1,2..3 and 6 but have had no luck. Did Hemingray not make them in these numbers? Any information would be great! Thank you!

The large numbers that you find on the crowns of Hemingray No. 40 insulators are called shop numbers. They are not mold numbers. You will find, for example, several of the Number 4 that vary significantly, so that they would not have come from the same mold.

At the time these insulators were being made, the workers were being paid piece work. The group of men operating one press was called a shop. Where a very common insulator style was being made, more than one shop would be making them simultaneously but they would feed into the same lehr for annealing. 

When they emerged from the lehr, the numbers identified them so that a count could be made and each "shop" paid accordingly.

The numbers had no other significance and no attempt was made to use all numbers in sequence. After seeing thousands of Hemingray No. 40, the numbers you list are the only ones I've seen and I think that's all that were used.

Several other Hemingray styles used shop numbers upon a few occasions but they are not common. Brookfield used many shop numbers on most of their common styles.