June 2002


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Written by
Sara Weiner

Photograph by
Ric Evans

A Glass Act

Look through a window. Whether it opens to a seascape or a city skyline or a brick wall, you have in your scope of vision one of the key themes of progress. Measure a cup of milk or water—up to the tick mark painted on the outside of the cup—and you illustrate the basis of scientific research for the past three centuries. Serve a daiquiri in a ceramic mug and you’ll get strange looks because you’re meant to see the pinky slush and not the vessel in which it is contained. You look through glass to see what’s on the other side, you look through glass to view its contents, but until you look at glass itself, you miss one of the most important aspects of technology.

Bob Greer doesn’t just look at or through glass. He works with it. He is the University of Pittsburgh’s lone glassblower.

Greer’s workshop in the physics department looks like a dead-letter office for glass. Crates of shattered test tubes and beakers are piled on the concrete floor, waiting to be made whole. Pinned to one wall are blueprints of custom projects he has drafted and will create for the University’s science professors. Deep shelves line the back wall with partitions for glass tubes ranging from the size of a knitting needle to the width of a grapefruit.

Glassblowers can create glass apparatus for scientific research in laboratories, universities, and industry. Glass is widely used in science and industry because of three main attributes: it is transparent, it is inert to most chemicals, and it is malleable. Most large universities employ scientific glassblowers to design and create custom equipment for chemistry and physics experiments. The glass is purchased as tubes and glassblowers bend them, twist them, and expand them into the numerous shapes required for use in research.

Bits of glass crunch beneath Greer’s heavy boots as he walks across the floor. His workbench is covered with glass fragments the way an administrator’s desk is covered with paper. A dozen glass tubes chime against each other as he pushes them aside.
He takes two of the tubes—each about the size of a magic marker—and dips them in the cone of a yellow flame. The rims of the tubes glow hot pink and he rotates them in opposition as the molten glass fuses the tubes into one. A few more twists and bends and this tube will form the condenser that a Pitt chemist needs to run his experiment.

The art of glassblowing is a fragile one and Greer’s masterpieces often return to him two or three times. He gingerly lifts a length of broken glass that he had shaped into a hollow coil. The job had taken him hours to design and days to create—melt, flow, fuse and again—and he had been proud of this coil. He’ll mend it like he restores all of his masterpieces that return to him in fragments, and he guesses it won’t be the last time he fixes it, either.

The basic responsibility of a scientific glassblower always has been to assist the researcher. A glassblower coiled the long tube of glass used in Galileo’s thermometer. A team of glassblowers fashioned the light bulb for Thomas Edison, as well as the necessary glass vacuum pumps. And a glassblower assisted Vladimir Zworykin in developing the tube that evolved into the television.

For more than 40 years, Greer has worked with glass. After graduating from Pittsburgh’s Schenley High School in 1956, he served a series of local apprenticeships before coming to Pitt 17 years ago.

At work on his latest project—which requires shaping glass rods into triangles—Greer holds a thin tube in the fire and yellow flames swallow up the glass. He lowers the goggles that have been resting on his forehead and the flame becomes translucent blue and the glass tube glows pink—brightest in the hottest areas. Besides protecting his eyes, these lenses act as a color filter so he can see what’s happening in the fire.

While the lenses allow him to see which parts of the glass are hottest, he works mostly by feel. Glass is sticky when it gets hot. It is an amorphous solid, which has no definite melting point. Unlike crystalline solids such as ice, which melts at exactly 32 degrees Fahrenheit, glass gradually softens above 500 degrees, then becomes more pliable with increasing temperature. Once in the flame, glass needs to be moved constantly to get the desired flow. To blow a flawless sphere, the stream of air from a glassblower’s lungs must be even, like playing a flute.

As Greer manipulates the glass in the flame, his every breath is like inhaling a blast of air from a hairdryer. Yet, he doesn’t seem to notice.

At 65 years old, he says he isn’t ready to retire “just yet” from the craft he loves. His hands, red and chapped from the dry heat of the flame, still hold the glass tubing steadily as he waits to sense that moment when the glass under fire starts to give way.

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