Making marbles out of liquid fire

It's no problem if Josh Simpson loses his marbles. He can just make some more. The Shelburne Falls, Mass., glassworker also makes elegant vases for Tiffany and intricate glass "planets" that are true works of art. But today he has generously agreed to show us how marbles used to be made, by hand.

Almost all playing marbles today are made in factories. But the principles involved in making marbles by machine or by hand are similar.

For one thing, it's very hot work. The gas-fired glass furnace in Mr. Simpson's studio is 2,400 degrees F. That's hotter than lava from a volcano. Simpson and his co-workers must be very careful. They wear special gloves, protective sleeves, and dark glasses.

Glass is a blend of sand, soda ash (a mineral), and lime (the rock, not the fruit) that's heated, then cooled.

Simpson begins making marbles by selecting several slabs of colored glass. These will become the "cat's eyes," the swirly bands inside the marble. Cat's-eye marbles were developed in Japan in the 1950s. They were an instant hit with American kids. Before that, opaque, multicolored "corkscrew" marbles and brightly colored clear-glass ones were popular.

Using more pieces of glass, Simpson assembles a glass cylinder about 7 inches long and 4-1/2 inches in diameter. He fits the pieces together like a puzzle, with colored glass at the center and wedges of clear glass around the outside. Loops of wire hold it together. Such cylinders are used to create long glass rods, collectively called "cane."

The glass cylinder could be heated as a unit, but that would take 12 hours. This time, Simpson uses a shortcut: He disassembles the block. Then he begins again by heating the colored-glass slabs and welding them into a star shape.

Then he and a skilled co-worker, Alex Brezinski, take globs of molten clear glass from the furnace and pour them between the arms of the colored-glass "star." They use a variety of tools, including metal pipes called "pontils" (pon-TEELS), to handle the hot glass.

The glass must be hot enough to be malleable (easy to shape). To keep the glass hot, a minifurnace called a "glory hole" is used. The glass is stuck into the glory hole every once in a while to reheat it. Handling hot glass is like handling honey - but you have to be even more careful that it doesn't drip onto the floor. The molten glass even has the amber color of honey.

Now the heated marble core is stretched like taffy between the ends of two pontils, first by Simpson alone, and then with Mr. Brezinski at the other end. As they pull, they twist the "cane" of glass to create swirls of color.

The farther the core is stretched, the thinner the cane becomes. If you draw it out 60 or even 80 feet, it will be as thin as a pencil. The thinness of the cane determines the size of the marble. Today, Simpson is making giant-jawbreaker-size marbles. The glass is stretched into a six-foot-long cane. It is cut off and set aside to cool.

Later, Simpson will use a diamond-bladed saw to cut the cane into four-inch-long pieces to use. In order not to waste glass, he makes a few marbles now from the butt end of the cane.

The end of the cane is reheated and pressed into a "forming block" made of cherry wood. As Simpson presses the cane into the water-soaked marble form, he rolls the cane back and forth, using the pontil attached to the end.

The water in the block turns instantly to steam. This layer of steam makes it easier to turn and shape the hot glass in the form. The water also keeps the wooden form from warping or catching fire. Periodically, the form is rewetted.

It takes a lot of practice to make a marble that's almost perfectly round. Simpson figures you need to make 1,000 marbles before you can do it well.

When the marble is nicely shaped, it's broken off the block by striking the joint with a heavy knife. A hydrogen-fueled torch with a 5,000-degree F. flame will smooth out the rough spot.

After 16 hours in an annealing oven to cool (slowly, so it won't crack or shatter), the marble is finally ready to admire - or knuckle down with.

(c) Copyright 2001. The Christian Science Monitor