Locke: Hemingray or Brookfield?

The Insulators

Left to Right, Top to Bottom:


Row 1:


Row 2:

Row 3:

Row 4:

Row 5:


Copy at the bottom of display is a copy of an advertisement from the March 4, 1893 Electrical World, showing a CD 287.2, and advertising the Fred M. Locke & Co. steel pin with cast iron base.

Some Additional Facts

Study Observations

Additonal Observations


Still Up For Debate

The Timeline Originally, it was thought that the CD 287.2 was introduced by Fred Locke around 1893. The narrow dome variant was probably first, then the wide dome variant with slightly extended middle skirt was an improvement. The CD 287.1 was introduced some time after May 22, 1894, and continued in production until around the time of the dissolution of the partnership in mid-1895. The CD 287 was then produced for a number of years. However, there are a few problems with that theory:

Alternate Timeline CD 287.1 was introduced, manufactured by Hemingray, sometime around mid 1894. About a year later, Locke had Hemingray make the CD 287.2. At about the same time or a little thereafter, Locke switched to Brookfield, and they made the narrow dome variant of CD 287.2. A little thereafter, they made the wide dome variant. Brookfield obtained the CD 287.1 molds originally used by Hemingray, reworked them into the CD 287 (causing some blotouts to remain visible), and subsequently continued to make this shape. There's a couple problems with this theory, too:

The correct answer is probably neither of these, but some combination of the two, with perhaps some overlap in production dates.

Continuing Research

If you have a CD 287 LOCKE [070] (which has the "F.M.LOCKE & CO" marking, not blotted out), we would love to see it. Also, if you have a CD 287.1 LOCKE [020] (which has the "& CO" blotted out), we'd like to see that too. Both of these pieces could give meaningful clues as to the topics discussed here.

Many Thanks

to those who contributed insulators for examination, and who discussed the questions surrounding these insulators: