Ravenswood Glass Novelty Works
GLASS MARBLES BY THE MILLION
By Bill Random (Science and Mechanics April 1945)
From the Marble Museum’s collection
April 1945 Eighty million is a big figure in any language and 80 million glass marbles are a lot of marbles, but even that is a small part of the total made by factories in the United States for kids of the world; I say world, since shipments are made through jobbers and exporters to all parts of the globe. There are just seven plants in the United States which manufacture glass marbles and all but one of them are located in West Virginia.
No other state can boast such business monopoly as West Virginia can with a glass marble factory in each of these towns: Pennsboro, ST Marys, Parkersburg, Ravenswood and two in Clarksburg. The lone outsider is in Ottawa, Illinois.
The plant in Ravenswood, West Virginia, using typical production methods in which the accompanying pictures were made, was originally organized in 1931 as the Ravenswood Glass Novelty Company new research may place the company’s beginning even earlier. In 1943 it shipped about 80 million glass marbles to the trade all over the world. Its owner, C. W. Trunbull, ingenious president of the concern which makes the most of materials at hand and who designed and built most of the equipment used, took over the business in 1932. At present they manufacture only glass marbles. He intends, after the war, to branch out into the making of general line of glass novelties.
After spending a good part of a lifetime, 30 years, in the clay pottery business, Mr. Turnbull took over the plant during the depression, confident that by careful management he could build up a good business. He succeeded with the help of his wife and two daughters even though he admits that during the days of the N.R.A. he almost folded up; somehow, however, he managed to keep his corporate body and soul together. As a result of war conditions, considerable difficulty is being experienced in procuring the necessary materials used. In addition to sand (silica), there are some 16 chemical compounds used to control melting temperatures, brittleness, and colors. Some of the ingredients cannot be obtained at all during the war and substitutes must be used.
Sand melts at a very high temperature, so fluxing materials such as zinc oxide, soda ash, feldspar, fluorspar, and borax are added to the sand which reduces the melting temperature of the mixture to practical values. The glass chemist or ceramic engineer needs to know much more than how to melt sand to make glass, since the ingredients needed to be added in exact proportions for color control. Some of the chemicals used are cobalt for blues, manganese for purple, manganese and iron for browns and black, selenium for pink, sulfur for yellow, and cadmium sulfide for yellow and red. Manganese is used chiefly as a classifier or de-colonizer. Antimony oxide is added to control brittleness.
Batches of glass are made up for stock in clear, white, or solid colors which are added together in the furnace or tank over the marble-making machine in exact proportions depending on the colors required by the customer. Such specifications as clear, solid colors, and striping is done by putting the various glass colors in the furnace in layers or laminations so that the molten glass runs from the furnace streaked with the colors rather than with the colors mixed to form a particular color. A typical formula for a batch of solid glass (purple in this case) is: Silica (sand) 330 lbs, Soda Ash 150lbs, Calcium (lime) 15 lbs, Barium Carbonate 3 lbs, Sodium Nitrate 7 lbs, and Manganese 12 lbs.
The marble glass is tapped from the furnace or tank over the marble machine through an adjustable orifice, which controls the diameter of the finished product. The stream of glass is cut by part of the marble machine called a shear which shuttles from one side to the other of the glass flowing through the orifice so that the piece cut off drops to one side or the other onto the parallel, spirally-grooved rollers of the marble machine. Seven sizes are made: 1/2″, 9.16″, 5/8″ 11/16″ 3/4″, 1″ and 1 1/4″. Two orifices are used; a 3/4″ for marbles up to 11/16″ in diameter, and a 1 and 1/4 inch orifice for all larger sizes.
The marble-making machine is movable, so that it may be taken away from the furnace or tank for repairs to it or to the tank. When being used, it rests on the floor so that the stream of glass flows to the center of the machine to the end farthest away from the center and, in rolling along in the spiral groove, is made round as it cools. Rolling off of the end, the still red-hot marble tumbles down a through to a keg or box. One marble rolls down one set of rollers, while another rolls down in the opposite direction on the other set of rollers.
After the finished marbles have cooled, they are fed into a sizing machine which consists of two shafts of steel, one revolving, and set out of parallel so that the ends nearest the box of marbles being fed onto it are close together, while the other ends are father apart–or, in other words, in a letter “V” fashion. As the single marbles roll down the shaft, the small ones fall through first and the intermediate and larger sizes afterwards. This machine is likewise turned by an electric motor. The various sizes fall into boxes below the machine, as shown in the picture.
The boxes of marbles taken from the sizing machine are carefully inspected for defectives – which are discarded. From the inspection table good marbles go to the packaging machine. This is a simple affair made of materials at hand. The operator controls the number of marbles for each box by operating a foot pedal (an iron rod stop in the groove in which the marbles roll down from the bin) counting the number automatically. After the stop has been inserted, the marbles below it are permitted to roll down into a sack or paper box (when obtainable) held in the operator’s hands.
Sacks or boxes of marbles ready for retail trade are shipped in large paper cartons and as many as 50,000 loose marbles are sometimes shipped in barrels to jobbers and exporters for world-wide distribution. Shipments are frequently made to foreign buyers direct from the factory on orders of Unites States exporters.
Ravenswood Marble Identification
From a selection of marbles Donated by Greg Helmick
In 1944, Charles Turnbull died and his son-in-law, Paul Cox, resumed the business in 1947. Under the leadership of Paul Cox the company began to use cheaper glass cullet rather than producing their own hot batch mixes of glass. The company continued operations until 1955. The building now sits in a residential setting and is used as a storage building. (Mike Johnson, Susie Metzler, and Dean Six)
We would like to thank Greg Helmick for contributing to The National Marble Museum project. We welcome donations of other interesting examples and original packaging from the Ravenswood Company. Thank You!