Embossings Found on Glass Insulators
(and their possible glass factory sources)
Below is a brief list of some embossed markings seen on insulators that stand for end user companies (or
in some instances, a brand name or initials used by the glass company)
which may not obviously indicate the factory that made the piece. I cannot go into the minor embossing details that
may distinguish insulators made by a particular glasshouse, and just
as an advisory, I would kindly mention
that this information is NOT guaranteed to be 100% accurate. It is to the best of my present
knowledge, and I would appreciate any corrections or clarifications
for this list below, so please feel free to send any to me if you can help out!
I would recommend consulting various reference books within the insulator collecting hobby
as well as other knowledgeable collectors for more
information on the subtle differences between the
products of different glasshouses. A very good source of info would be back issues of Crown Jewels of the Wire,
the magazine of insulator collecting that has been published since 1969. Many informative articles
have been published in it over the years.
PRIMARY EMBOSSING...........................GLASS FACTORY SOURCE
A.T.&T...........................................Brookfield Glass Company
AM TEL & TEL...Brookfield, Hemingray, Western Glass Mnfg.Co, Sterling
B (on the side, normally below wire groove)....................Brookfield
B.& O...........................................Brookfield, Hemingray
B.G.M.CO........................................................Baltimore
Birmingham.............................................probably Lynchburg
Brooke's............................Uncertain New England-area glasshouse
B.T.C............................................................Diamond?
C.& P.CO...................................................Brookfield
C.D.& P.Co.................................................Brookfield
C.E.L.CO..........................................................Unknown
C.E.W................................San Francisco or Pacific Glass Works
C.N.R..............................Unidentified Canadian glass company(s)
C.P.R..............................Unidentified Canadian glass company(s)
Cable.......................................Brookfield, Hemingray, others
City Fire Alarm................................................Brookfield
Columbia............................................Hemingray, Brookfield
Combination Safety.............................................Brookfield
Diamond logo............................................Diamond, Dominion
Diamond superimposed over oval and I.......................Owens-Illinois
E.L.CO.........................................Brookfield or unidentified
E.R..........................................at least some are Brookfield
E.R.W.............................................................Unknown
Fall River.................................................... Brookfield
G.E.Co............................................. Brookfield, Hemingray
G.N.R........................................................... Diamond?
G.N.W........................................................... Diamond?
G.T.P.TEL.CO.............................................Canadian company
H (on dome).....................................................Hemingray
H.G.CO..........................................................Hemingray
H.G.W.(monogram)..................................................unknown
Jumbo..........................................................Brookfield
K.C.G.W.............................................King City Glass Works
Kimble.........................................Hemingray (Owens-Illinois)
Knowles...........................................................Novelty
KPP inside an oval................Kerr (Kerr Packaging Products Division)
£ (British "Pound" Sign).........................................Sterling
L.G.T.&Co.................................................Brookfield?
Locke............................................. Brookfield, Hemingray?
Lowex.......................................................... Hemingray
M.& E.Co......................................................Unknown
McMicking.......................................................Uncertain
Montreal.........................................................Diamond?
Mulford & Biddle..................................................Unknown
N.E.G.M.CO................................New England Glass Mnfg. Company
N.W.& B.I.T.Co...............................Unknown Canadian company
N.Y.& E.R.R...................................................Unknown
P in a diamond (CD 134)...........................................Unknown
P in a diamond (CD 154)...........Canadian manufacture, probably Dominion
P.R.R..........................................................Brookfield
Paisley...........................................................Unknown
Patent Dec.19 1871..............................................Hemingray
Patent Oct. 8 1907..............................................Hemingray
Patent Oct.8TH 1907 [NOTE "TH"]................................Brookfield
Patent May 2 1893...............................................Hemingray
Pettingell Andrews................................................Unknown
Postal...........................most are either Brookfield or California
Pyrex.............................................................Corning
Prism............................................................Novelty?
Santa Ana...........................................California, Hemingray
Seilers........................................................Hemingray?
S.F.............................................................Uncertain
So.Mass.Tel.Co................................................Brookfield?
"Star".....Novelty, Sterling, Harloe, possibly some Brookfield, Hemingray
Sterling.........................................................Sterling
Surge...........................................................Hemingray
T.H.E.CO............................................Brookfield, Hemingray
T.C.R.......................................Unidentified Canadian company
Tillotson......................................................Brookfield
Twiggs............................................................Unknown
U.S.TEL.CO(CD 121).............................................Brookfield
Westinghouse......................................................Unknown
W.E.MFG.CO..........................................Brookfield, Hemingray
W.F.G.CO......................................Western Flint Glass Company
W.G.M.CO......................................Western Glass Mnfg. Company
W.U................................................ Brookfield, Hemingray
BACK TO THE GLASS INSULATOR FACTORIES HOMEPAGE
GLASS MANUFACTURERS' MARKS FOUND ON BOTTLES