Dario Dimare provided the explanation to Vernon Fellows' question about the extra lettering on the dome of his Brookfield signal (April 2006 issue, page 43.)

Vernon ask if the embossed (raised) letters "J E L" were placed on the dome by a factory worker carving his initials into the mold. We speculated that the still-warm insulator might have bumped up against something that resulted in a transfer of the lettering from the name "Brookfield", and that the letters were really "I E L".

Dario says the letters are from the Brookfield name, but they came about during the pouring of the glass, and not after it was poured. He explained that a "cold pour" occurs when either the glass is too cool, or the mold itself is cold. In either case, when (cold) glass is poured into a (cold) mold, it is (or becomes) rather stiff like clay, rather than molten. As a fold of the glass makes contact with the embossing, the letters are formed. But as more glass enters the mold, the first portion may fold over, in this case, into the dome area. Because the glass was too cool, the embossing is partially retained. Dario says a clue that the extra letters were created in this manner is the wrinkle of glass across the dome that indicates the glass folded over as the insulator was being made.

According to Dario, a lot of so-called "ghost embossing" are created in this manner. When inspecting one in your collection, watch for a wrinkle in the glass in the vicinity of the extra embossing.

Dario also noted that if the "ghost embossing" occurred from a warm insulator bumping into another object, the resulting letters would be incused (sunken) instead of embossed (raised). Thanks, Dario, for explaining why extra letters can sometimes appear in the strangest places on insulators.