Glass Insulators: a Brief History from a Collector's Perspective
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Glass Insulators: a Brief History from a Collector's Perspective

Why I collect glass insulators, the history of glass insulators

Most people who collect things usually stick with easy to get, traditional items such as baseball cards, coins, arrow heads, etc. Some people like to be different though and collect more unusual things like typewriters, fishing reels, barb wire and telephones or in my case, the glass insulators that were once on virtually every telegraph pole in America.

To me, insulators look more like a work of art than a simple component that was mass produced from approximately 1850 to 1950.

Insulators were designed to keep the wire from coming in contact with the cross arm which would result in current bleeding off into the ground.

For a hundred years the efforts of inventors to improve the insulators ability to keep the current loss at a minimum and protect them from vandalism created some interesting shapes that resembled every thing from Trojan helmets to salt shakers, ginger bread men, bat ears, Mickey Mouse ears, Pluto the dog, mushrooms, bee hives, bullets, castles and even a giant screw. Some were constructed with pleated glass or copper skirts to create a longer path of resistance for the electrons to follow down the pole to the ground. It was also hoped that the pleated skirts would cause the insulator to break off in small chunks when hit by a bullet or rock instead of completely shattering.

Insulators came in several different shades of blue, green, white, black, purple, amber and gray. The various colors really didnÂ’t mean any thing. The glass manufacturers used what ever glass was left over at the end of the day to make the insulators resulting in some beautiful colors. They werenÂ’t too worried about creating perfect insulators so iron and other impurities were often in the glass when they were made. This would sometimes cause slight imperfections such as milky swirls and other flaws that would make them quite valuable to collectorÂ’s decades later. Embossing errors such as backward letters were quite common too.

If there was enough manganese in the glass, clear insulators would occasionally be turned purple by the sun over a long period of time. Most insulators are approximately four inches in height and three inches wide with a few smaller ones about the size of a quarter. The grand daddy of them all is a green giant weighing in at a whopping 57 pounds and measures 18 inches in width making it the biggest insulator ever found in the world.

My meager collection of 400 different insulators is pale in comparison to the larger ones such as a collector in Kansas City who has over 5,000. They are still out there to be found in places such as estate sales, antique shops, CraigÂ’s List and eBay.

Telegraph and power poles were often situated on railroad right a ways so try walking along abandoned tracks on a beautiful spring day. You might just find a few of these ancient little treasures on an old pole that has long ago succumbed to father time and is now laying on the ground waiting for some lucky person to give its insulators a good home.

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Comments (3)

This is really interesting. Back in rural western New York state back in the early 1970s, my older brother and I used to collect these. Found roadside whenever the phone company changed telephone poles, these glass insulators were either left in~site attached to the crossbeams and whole tossed into ravines or ditches, or the insulators remain after the crossbeams rotted away, or were tossed into the brush, etc. We had dozens of them. Green, clear, white, tan and brown-to-black. I remember a clear glass one that had purple swirlies in it... manganese, eh? Kewl... wish I still had these.


I have a friend who has Barrels of them and was wanting to sell them. There is 5 differnt styles, 2 of them are clear and 3 are green. This is what we have found so far. Some are power and some are telephone. My dad knows the difference. so I know there is more than one type.

If interested give me a buz.


Great article! I too, collect insulators and have been for awhile. I find them to be a very special time in our history as a nation. I go out about 3 times a week and walk the lines in and around my small town in Texas. I have found as many as 20 in a trip and as few as 1. I find that the hunt is just part of it.. getting out and finding and bringing home something that has layed on the ground, been hanging in a tree or buried under a mound of leaves, then cleaning them up until they sparkle!! Some would say just go and buy them from others and thats fine also but when you spend a couple of hours hunting and find some...just an all around great feeling for me!!