Porcelain Insulator News
by Jack H. Tod
Reprinted from "INSULATORS - Crown Jewels of the Wire", June 1974, page 23
Preferably direct porcelain news items and questions directly to Jack H. Tod,
3427 N. 47th Place, Phoenix, Ariz. 85018. All mail will be answered if reply
stamp is enclosed, and the most newsworthy items and questions of general
interest will be published as space permits.
NEW PORCELAIN BOOK
Supplement to Collectible Porcelain Insulators, Second Edition, by Gerald
Brown, Two Buttes, Colorado 81084, softbound, 8-1/2" x 11" format, 70
pages, $2.50 ppd.
This book follows the format of the Second Edition and includes many new
insulators of all types from small standard porcelain items up through all sizes
and styles of pin types, including some rare and unique types never reported
before in any source. If you collect porcelains, you should get this book by all
Enclosed are shadow profile and dimensions on a most unusual G. P.
Co. insulator. It is a mottled reddish black and gray with creamy yellow edges.
Note that it is very similar to the ordinary U-98A mine insulator but that the
hole does not go through. These were found in Buffalo and were mounted upside
down under the crossarm just as with duplex insulators.
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This is indeed puzzling, and it just defies logic why they would make this
item as you have it, since it would trap water and be no better than any other
conventional insulator used upside down on a duplex pin. I doubt that it was an
intended design on the part of G.P., and it more than likely was supposed to
have been a conventional shape but that the threading mandrel was improperly
adjusted in the press setup. In any event, I think it best not to put this thing
in the style chart unless enough show up (and from other places too) to indicate
they really meant it.
Apathy is the greatest problem in America; but who cares?
Jerry Turner (Goshen, Ohio) sent this photo of two similar insulators he has.
The one on the right is said to have come from Australia.
The one on the left is supposed to have come from the first electric trolley
in Seattle, and a drawing of it is shown here. I also heard that one of these in
a California collection was dug in a Nevada dump.
I don't have any information at all on these old insulators, but they do look
like styles originating before 1900. Sketches in some of the circ-1900 patent
drawings show a tendency to use this general shape as examples of what an
insulator should look like, so I guess there were some around then for the
artists to look up at. Hopefully we'll get some paperwork in the future to show
who made these and when.
Dear Mr. Tod:
Just found in an old mine tower some U-97 mine insulators, dry process, skirt
rest (at large end pin hole) and embossed as shown on the enclosed sketch. The
Square-D marking is recess-embossed on the opposite end.
Thought this might be an unreported marking or combination of two markings.
R. L. Perkins
Rt. 1, Hillsboro, ILL. 62049
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No, this is commonly known, but I guess we just didn't point it out in any of
the various porcelain books. Ohio Brass Company makes only wet process
insulators, and all their dry press items such as this were made for O-B as
contract items by other porcelain companies who did make dry press ware. You
will also find the Square-D identification marking on the other end of the
larger U- 94 mine insulators made on some die sets.
Note that the O-B marking is embossed (letters punched directly into the
die), and I presume O-B owned the die sets - as was customary on many items
contracted out to various porcelain manufacturers. The Square-D marking is
recess-embossed because it is a small brass cutout which is merely soft-soldered
to the die, and can be easily removed if and when O-B wanted their dies
This was common practice with all companies such as Square-D, Findlay,
Thomas, etc. making dry press items for others under contract. They many times
added their own identification to dies with the other customer markings. Note
that many of the U-188 dry-spots made by Square-D Co. have the Square-D marking
on the top of the large part (under the top cap).
I have been collecting insulators for about two years now and have just
recently started taking interest in porcelain.
Enclosed is a sketch of an insulator I have which I am curious about. Any
information you could give me would be much appreciated. Doug McCullough
Maple Ridge, B.C., Can.
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I don't know exactly what the insulator you have is, but is some form of
outlet bushing and is probably used on equipment such as transformers or as a
pothead cover. The four small unglazed spots are firing rests necessary in its
The SLATER marking is undoubtedly for W. Slater Co., Ltd., 34 Sydney St. (as
of 50 years ago), Hamilton, Ont., Canada. This company was established in 1907
as Slater & Barnard, Ltd., Norman Slater president, and they were listed in
directories as manufacturers of poleline hardware
I have some "slab" insulators with very pretty glazes and which are
similar to your item and suggest that every collector should have some insulator
like this to use as a pencil holder - 4 pencils in your case.
I am enclosing a sketch of a light brown porcelain insulator that I recently
obtained from a friend, and this one has me stumped. I am mainly a glass
collector and not too familiar with the porcelain end of the hobby. I do read
your column in Crown Jewels and find it most interesting and would consider you
the last word on this subject. I went through all the back issues and other
reference books I have but could find nothing on this item. It was found in an
old mansion here on Long Island that is being razed and was supporting wiring in
the cellar according to the person who found it. I would appreciate any info you
have on this insulator.
William 0. Davis
Bay Shore, N.Y.
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Your item isn't a sketch; it's a work of art. I think that trade name is also
very apropos for this thing!
You didn't dig deep enough. I first corresponded with Frances Terrill about
this standoff insulator in May 1972, and she ran it in OBX, page 36 of the
August 1972 issue. Gerald Brown also lists this item, along with a shorter
version of the same thing, in his new supplement.
In any event, I was stumped on it two years ago and still am. We know what it
is but would like to know who the trade name belongs to. I didn't run across
this in my patent survey 1890 through 1919 and haven't been able to get back on
the detail search from 1920 to date. Also, I simply haven't had the time to
initiate my detail search of tradenames which would give the answer on this.
This is a sad state, since this is obviously a very interesting insulator type.
If any reader knows the company using this insulator tradename, please fill us
As usual, while digging for bottles I find new insulators to add to my
collection. I found an E. P. Co. two-wire cleat, and a nail knob puzzles me. It
is white glazed and embossed B & D on the top. In the February column you
mentioned a headed wall tube marked BD. Is this in most cases the same company?
If so, do you have any information on this yet?
Also, I've always wondered where you find the time to answer letters, write
articles, and do so much research. Pardon me for being so inquisitive, but how
do you manage it all? It sounds like a nice life to lead.
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No, the BD on the tube is a company or tradename of unknown meaning. The B
& D on your nail knob is not a company name; it is a general reference to
the Buffinton & Dow patents on forms of reversible cleats which have
interlocking grooves and ridges on the mating surfaces and also providing a
porcelain barrier between the mounting screws and the conductors. This principle
was also applied later to split knobs (nail knobs, that is).
The B & D designs were so popularized that everyone started adopting the
design, and most catalogs of the past 50 years head up the listings with a large
"B & D CLEATS". I presume the reference was so generally used
after a time that some company capitalized on it by using this marking which
would mean something to customers more than some obscure porcelain company name.
Do you recall when a tobacco company came out with "BRAND X"
cigarettes a few years ago? Same principle.
To your final questions, I have time to do all this insulator
"work" because I am retired from engineering. I work on insulator
stuff full time and to the extent I sometimes have little time for the actual
collecting part of it. If I wasn't working on insulators, I'd be on some other
project full blast. Yes, it is quite a life, but then anything is when you enjoy
what you are doing.
The reason I have done a vast amount of research on insulators is that I
don't believe in doing any job in a half-vast manner.
On the following pages are brief histories of several more porcelain
insulator companies. I don't know if these are interesting or worthwhile to our
readers or whether they are a waste of space. If you have any strong feelings
one way or the other, why don't you drop us a card and we'll go accordingly.
Ravenswood Porcelain Co.
This company, located on the banks of the Ohio River in Ravenswood, West
Virginia, was founded in 1921. The original officers were C. E. Mason, Pres.;
Mike E. Ginther, Secy; Charles Trumbull, Gen Mgr; Bill Hall, Treasurer.
The company made only dry process porcelain and sold a complete line of
standard porcelain knobs, cleats, etc. The marking used on these items was
"R. P. Co.". They also made contract item such as Sackett mine
insulators, rack spools for Seyler, St. Louis Malleable, etc.
This company was one of 6 electrical porcelain companies which were merged to
form Porcelain Products, Inc. in 1927, and it was almost immediately shut down
and thereby ending production of electrical porcelain there.
The property was bought in 1929 by T. V. Milligan but remained idle until
1935 (or 1937?) . (Note that he had operated T. V. Milligan Porcelain Co. in
East Liverpool from 1915 until selling it to Peach Porc. Co. in 1929.)
Gus Trenle, owner of Trenle Porcelain Co. in East Liverpool (1915-1937),
bought the Ravenswood plant in partnership with H. W. Blake in 1937. The company
name was Trenle-Blake China Co., and it made a complete line of hotel china
until closing in 1965. It was bought and operated by Harold Compston, first
employed by the plant in 1921, and operated substantially without change until
closing again in 1969. The plant is still idle.
Superior Porcelain Co.
This company originated as West Virginia Porcelain Co., founded in 1919 and
located in New Haven, W. Va. First production of insulators (all dry press
items) was in 1920. The company underwent increasing financial difficulty and
was finally put up for auction in 1925.
It was bought by a group of 10 or 12 local people and incorporated as New
Haven Porcelain Co.
(Note: I know of no markings attributable to these two early names of this
George 0. Anderson, who had owned Anderson Porcelain Co. in East Liverpool
from 1904 until selling to the General Porcelain Co. combine in 1911, remained
with G.P. Co. after that merger. But he became disenchanted with that
arrangement after the second merger in 1927 to form P.P., Inc. He quit P.P.,
Inc. and bought the New Haven plant from the local stockholders in 1929.
He changed the name to Superior Porcelain Co. and manufactured a complete
line of standard porcelain plus many specialty and contract items. Markings on
standard porcelain and proprietary items from this plant have been
"SUPERIOR" and "S. P. Co.".
The company office was always located in Parkersburg, W. Va. where Mr.
Anderson lived. The plant was operated by G. O. Anderson and his son, Smith
Anderson, who preceded him in death. The plant was sold by the Anderson estate
in 1964 to the present owners, once again a group of people in New Haven, and
the name was changed once again to New Haven Porcelain Co. The company still
sells under the "SUPERIOR Line", and items still carry the same
An oil-fueled space heater got out of control in December 1970, and the
entire plant burned to the ground. It was rebuilt (this time with a metal
building!), and the first kiln firings after rebuilding were in January 1973.
(Note: When I visited the plant in 1973, one of the small runs they were
making at the time was an order for 60,000 of the standard porcelain #22 split
knob from a construction company in New York, and two other porcelain companies
had identical orders from the same source. This just goes to show a proven
design never fades away.)
R. Thomas & Sons Co.
Richard Thomas and his father, John Thomas, came to this country from
Staffordshire, England. They soon opened a small pottery in East Liverpool, Ohio
which at that time was the center of the industry in the United States. This
small plant opened with just one kiln in 1873 and was located on the north side
of West 7th St. in East Liverpool. The name of the company was American Knob
Works, and the main product was clay door knobs.
(Note: The original plant location has been eradicated by a large freeway
interchange there, but you can still kick up these old door knobs along the
expressway drainage ditches where the grass hasn't covered them over.)
The company was reorganized in 1884 and expanded to manufacture porcelain
wiring knobs and other electrical porcelain items. The name was changed to R.
Thomas & Sons. Shortly thereafter (one source states 1885), the first
porcelain insulators were shipped to U.S. Lighting Co. of Chicago, at the time
of the National Electric Light Assn organization. By 1887, Thomas was marketing
insulators to Brush Electric Assn., Detroit Electric Works, Pittsburgh Electric
Co., Central Electric (Chicago), Keystone Light & Power Co., Westinghouse
Electric, and others. Thomas was the main supplier of the period, and expansion
The company, incorporated in 1892 under the name "R. Thomas & Sons
Co.". Its catalog of that period contained three outdoor insulator types
and nearly 100 for interior use. All the insulators for the 1892-93 Chicago
World's Fair (installed by Westinghouse) were made by Thomas. A third catalog
issued in 1894 showed nearly 300 insulators.
(Note: A knob has been reported with a marking of "R. T. &
SONS", and this marking may have been the one used prior to the "R.
THOMAS & SONS CO." name change in 1892.)
The incorporation in 1892 resulted from continual rapid expansion which
culminated in Thomas having bought the entire porcelain plant of Westinghouse
Electric Co. At this time, Thomas had over 200 employees and was claimed to be
the most extensive works in the country making porcelain insulators for
electrical purposes as their specialty.
An even greater growth came when Thomas commenced the development of wet
process pin type insulators in the mid-1890's. Early in 1896, John W. Boch of
Thomas perfected the method of glaze-welding two or more porcelain shells
together by what they termed the "Glaze-filling" process (a patent on
which was granted in 1898). Starting in 1897, Thomas manufactured pin types, and
this business rapidly grew until Thomas was the second largest manufacturer of
these in just a few years. Thomas cataloged a fairly complete line of pin type
power insulators as early as 1904 and had a large share of the market for all
pin types by 1912.
At Lisbon, Ohio (15 miles from East Liverpool) a plant had been built in 1900
for the manufacture of semiporcelain, operating under the name Thomas China
Company and, according to one source, was owned by Al G. Mason, a member of the
Thomas "family". This plant was absorbed into R. Thomas & Sons Co.
in 1905 for the manufacture of electrical porcelain insulators. The plant was
located on the south side of Washington St. at the river crossing in Lisbon.
During this period, general manager of the Lisbon plant was A. G. Mason, and J.
R. Holmes at East Liverpool.
The Lisbon plant was converted to a modern insulator plant in 1918, and the
East Liverpool plant was closed in 1927. In May of 1957, the R. Thomas &
Sons Co. was bought by the H. K. Porter Co. and absorbed into its Delta-Star
Electric Division. The product thereafter consisted mostly of suspension
insulators. Porter closed the plant in 1963. It has recently been undergoing
refurbishing and refitting as an aluminum extrusion plant.
Markings on Thomas dry process insulators (after 1892) include "R. T.
& S. Co.", "THOMAS" and "T". Except for early Boch
patent items, markings on both dry and wet process pin types has always been
For the sake of completeness, Richard Thomas' four sons were George W.,
Lawrence L., Atwood V. and Charles R. Thomas. By the 1920's much of the company
management was under the two sons of George W. Thomas - Richard G. and L. M.