2001 >> July >> Porcelain Threadless Insulators  

Porcelain Threadless Insulators
by Doug MacGillvary

Reprinted from "Crown Jewels of the Wire", July 2001, page 32

For those not familiar with porcelain threadless, there have been 23 different U-numbers assigned. (But it has been discovered that the U-978 is in fact threaded.) This doesn't mean that other styles don't exist, but if there are other styles, they have not been reported. Added to the pin type porcelain threadless is the porcelain block insulator, which dates back, at least, to 1848.

U-970 The porcelain "Egg" was used extensively by the Confederate Army during the Civil War. This is not to say that it was not manufactured many years prior to the war. The "eggs" could have been made by a number of small pottery works, such as Parr's Pottery Works in Richmond, VA. No doubt, this style was made through the 1850's and 1860's.


Three different glazes on U-970 "eggs" 
dark brown almost black, medium brown and gray.


U-971 This rare piece is from Bennington Pottery in Bennington, VT. It has three short petticoats, in the same fashion as the U-979 and U-980 Elliott styles. There are four of these beauties known to exist. The one on the right has no glaze. They were purchased as a group at a Massachusetts flea market in the early 1990's.

U-972  Elton Gish called this an "overcooked brown"; "the ugliest and most crude glaze that I have ever seen." I first saw this piece in a display at the Berea, OH National in 1976. I have not been very successful in filling in any background on this most unusual piece, evidently, the only known example.

U-973  This has to be a variant of the U-970. It also has its roots in the South and might have been a piece used by the Confederate Army, although that is only an assumption. To date, this is the only U-973 known to exist.

U-974  This "Hat" style seems to have had its roots in the Northeast. One was dug near Rome, NY in the early 1970's. I know of a second that was purchased in a Connecticut antique shop about ten years ago. The style was very popular, yet the number of porcelain "Hats" that have surfaced are few.

U-975   These two examples have identical features to the U-974, but the size of the U-975 is somewhat smaller. Five of these were found in Guelph, Ontario in 1982. One would have to believe that they are of Canadian origin. Recently, another specimen surfaced in the area of Syracuse, NY.

U-975A  This U-975A was dug in a Union Civil War camp along the Southeastern coast of Texas near the Mexican border along the Rio Grande River. The camp is believed to have been occupied by the 13th Corps. It was dug in 1998.

U-976   This is the smallest of all of the porcelain threadless! This "Hat" measures barely 2-1/2" tall and was dug in Pennsylvania. This is a "one of a kind".

U-977  This is another "Hat" style. It is extremely rare. The white glaze is similar to the U-985, U-986 and U-987, which were all found in the Ohio area.

U-979  Gerald Brown likened this Elliott type to a fog bowl shape. I think it is closer to the shape of the CD 151. A truly rare Bennington product, I know of only four.

U-980  This is the "Horned Elliott", a very popular threadless, dating to the early 1850's. The white flint insulator was invented by E.B. Elliott. This is another Bennington Pottery product.


Gleason's Pictorial Drawing-Room Companion
October 22, 1853 Issue

With the discovery of this article, over thirty years ago, came the tie between the Bennington (VT) Pottery Company and the insulator industry. The article detailed an elaborate exhibition of Bennington Pottery's ware at the Crystal Palace in New York City in 1853. Clearly shown in the woodcut are the U-979, U-980 and U-981. (Top pedestal on left surrounding base of urn.)

Quoted from the article: "Telegraph insulators, in white flint, are on exhibition. This ware has been employed on the telegraphs in the vicinity of Boston: among these specimens is a patented form, recommended by Mr. Bachelder, which has a shoulder with a re-entering angle of forty-five degrees; this angle causes the wind and rain to pass downward and prevents the inside of the insulator from being wet."


U-981  This is the "Elliott Hat". It is another white flint piece from Bennington. Its insulating properties were equal to glass and superior in strength. George Prescott, author of the 1864 "History, Theory & Practice of the Electric Telegraph" writes of the Elliott white flint insulator: "Although it is not a perfect insulator, it approaches nearer the requirements of such than any other which has been tried."

U-982  Jack Tod wrote this about the U-982, "I guarantee, you will enter a state of euphoria if you ever hold this beautiful and unique specimen in your hands." The Rockingham glaze of the Bennington Pottery Works make this piece and the U-983 the centerpiece of my collection.

U-983  This hybrid has most of the general style of the U-982, except that it has a 12- paneled skirt and a dome that is very similar to the U-979. There are probably only three known.

U-984  This is one of two known specimens. It was supposedly found in Mobile Bay in Alabama. It was definitely used by the Confederacy. This piece bears resemblance to the CD 127.4 Western Union style glass threaded insulator, even though the threadless preceded the glass piece by many years.

U-985  This is the piece that is shown in Gerald Brown's 1974 book on porcelain insulators. I know of no other examples, although one would think that because of its great similarity to the popular CD 731 style, many more would be found. This piece was reportedly found in the area around Pittsburg, Ohio.

U-986  This is the "Slim Jim"! It surfaced in 1973 in Ohio and, to date, remains a one of a kind. It has a white glaze with specs of black showing through. It seems to have many of the characteristics of the U-985. There could be a tie between them because of the geographic background of each piece.

U-987  The unique peak top and bright white glaze make this "one of a kind" piece stand out. This insulator was originally found in the Ohio area. The crackled glaze has similarities to the other porcelain threadless styles attributed to the area.

U-988  This is the "Slash Top"! These unique white-glazed beauties were said to have been used on Confederate telegraph lines during the Civil War. The U-988's surfaced in 1975 in Georgia! There were approximately 25 located and they quickly found their way into collections. There is an excellent article about the "Slash Tops" in the February, 1976 issue of Crown Jewels of the Wire magazine.

U-989  This unusual piece was also found in the Mobile, Alabama area. It is thought to be another style of insulator used by the Confederacy during the Civil War. A closer examination of a fairly elaborate key-lock design in the pinhole would cast some doubt about this being a war-time product, except for the fact that examples of the U-989 were found at the Southern Porcelain Co. in Kaolin, Sc. Southern Porcelain was a major supplier of insulators to the Confederacy.

U-990  These are the "Teapots"! Gerald Brown wrote: "this insulator seems to me, to be the most interesting and among the rarest of all the porcelains that have been found." Although not the rarest anymore, it is still the most interesting. I have several, of which no two come close to another in color. There are two sizes: the larger is 4-3/8" diameter and the smaller is 3-7/8".

Jack Tod referenced the following to the 1939 book "Marketing Burned Clay Products", by A. Hamilton Chute: "A pottery in Kaolin, SC during the war, made porcelain and pottery insulators for use on the Confederate Telegraph Line." Jack then mused that "some of you insulator buffs should try out the dump digging in Kaolin. Wow, just the thought of finding that one!" That was in 1975.

In the February, 1997 issue of Crown Jewels of the Wire magazine, Dick Bowman proclaimed, "It is a mystery no more!"

The Southern Porcelain dump had been located and dug. The unglazed U-990 "Teapot" and porcelain block and examples of the specimens dug at the recently discovered site. The U-989 has also been linked to the Southern dig.

The Southern Porcelain Co. was founded in 1856 by William Farrar, who also had ties to the U.S. Pottery in Bennington, VT, another known producer of porcelain threadless. Southern made insulators for the Confederacy at least for the duration of the Civil War era. A fire consumed the factory in 1864, but a new porcelain company was organized in 1865.

One can only speculate about the years prior to and just after the Civil War. What was Southern Porcelain's involvement in the insulator business then?

U-1960  There are the only three known examples of the U-1960 in the hobby at this time. Although the shape is similar to other porcelain "Hats", the unusually large 1-5/8" diameter pinhole makes this Canadian piece unique to all other porcelain threadless. 

Displayed for the first time together at the 2000 national were the three known U-1960 "Hendersons", a most unique threadless "hat".


Reference is made in "The Telegraph in America", when giving an account of the Peoples Telegraph, "The insulators, instead of being made of glass, were of glazed earthenware, imperfectly vitrified, through the thin crust of which the wire soon sawed its way, and left the soft pottery exposed to the rain, which soon soaked into the mass." Peoples Telegraph ran from Louisville, KY to New Orleans, LA. Pictured here is a porcelain block manufactured for the Placerville and Humbolt Telegraph Company by the Pacific Pottery Company in Sacramento, California.


U-978  The U-978 (not pictured) mistakenly made its way into the threadless category. In fact, the only two examples of this style of insulator have been in the Smithsonian Institution's National Museum of American History since 1904. They have been photographed, measured, carefully examined and clearly are threaded insulators. In time, the U-978 should be eliminated from the list of threadless porcelain insulators.



These three blocks are believed to have been used on the Peoples Telegraph line.


THREADLESS PORCELAIN at the 2000 NIA Convention, Minneapolis, Minnesota 
Dr. Fredrick L. Griffin Memorial Award for Best Use of Threadless 
Best Exhibit using Eastern Insulators


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