The joy of glass

ALTHOUGH the man in the street may not know it, modern life is full of the inventions of Donald Stookey. His ingenuity lies behind the screens of tablets and mobile phones; behind glasses that fade to black as the sun comes out; behind the nose-cones of guided missiles, and cookware so sturdy that you can broil it in the oven, plunge it in the fridge and drop it on a stone floor, with damage to nothing but the soufflé that was in it.

Interesting, then, that Dr Stookey saw himself less as a scientist than an alchemist. This was because his field was glass, a material so unique and strange—not solid, liquid or gas, but a liquid frozen in an unstable state—that in 3,500 years of history it had kept its secrets intact. His liveliest mental companion, as he worked away for almost five decades among the smokestacks of the Corning Glass Works in upstate New York, was Johann Kunckel, first finder in the 17th century of a formula for gold ruby glass, who believed that cups made of this could transmit to drinkers the virtues of the philosopher’s stone.

He also saw himself as an explorer, the sort he had loved to read about in childhood, opening doors into unseen worlds; or, being an avid hunter and fisherman, as a tracker of elusive prey. Hence his original venture into glass, as he left MIT in 1940 with a doctorate but with job offers only from Corning and Nabisco, a bakery company. He did not want to bake, so chose to do research into milky white opal glass. He knew nothing of either the substance or the chemistry, but found it mysterious and beautiful and hoped it might be useful.

The job was still almost artisan, with his glass samples heated in one-pound batches in clay crucibles by a gruff old glass-blower. But he succeeded after some years in making opal glass photosensitive, so that three-dimensional designs could be etched into it by the action of light. Taking clues from nature, he made this “Fotoform” glass resemble frost-lace, spiders’ webs and a honeycomb, in which honeybees actually produced honey. He also perfected a glass which, in daylight, looked like marble, and now covers the north face of the UN headquarters in New York.

A nucleus of gold

The joy of glass, he soon discovered, lay not only in its resilience and transparency but in its very instability, and its yearning to reach a lower-energy crystalline state. Every one of his inventions depended on a process called “nucleation”, in which the smallest stable trace of any element, added to molten glass, became a nucleus round which crystals would grow until, by cooling, he chose to stop them. Tiny light-scattering particles of sodium fluoride made opal glass; mites of copper or gold made the ruby glass he so admired. These too he rendered photosensitive, so that after exposure to ultraviolet light photographs could appear within them. One of his first attempts was a paperweight containing a photograph of his wife Ruth in her wedding gown; and in wartime the Treasury Department almost took up his idea of making pennies not of scarce copper but of copper ruby glass, with Lincoln’s portrait magically suspended in them.

That notion proved too costly, however. (So did the pleasing idea of making mirrors and spectacles for spies which, when exposed to light, would reveal secret messages.) Indeed some folk at Corning thought Dr Stookey was just playing around, making things that were decorative rather than commercial. His natural shyness, reinforced by partial blindness, did not help; but with every prod something extraordinary appeared. He made glass with thousands of holes per square inch, to guide electron beams for colour television sets, by dissolving a crystallised photograph of a vast array of dots from Fotoform glass with hydrofluoric acid. He made glass that was rubbery and easier to saw. He imagined a future in which glass, with its raw material so abundant everywhere, could replace not only petrochemical plastics but also metal and wood.

One invention, too, earned money in style. This was glass-ceramic, patented in 1960 as Fotoceram and marketed as indestructible Corningware dishes, so popular in America that by the 1980s six pieces of it (originally white, with blue cornflowers) could have graced every household. Dr Stookey invented this by accident when, having left a piece of Fotoform glass in too hot a furnace, he found it had turned milky and bounced off the floor when, cursing, he tried to yank it out. This glass had so intensely crystallised on reheating that it dropped with a clang like steel.

He made some money from that: enough to indulge his passion for motor cruisers and to have a fair number of extra-laboratory adventures, including a sea-plane wreck in a freezing Canadian lake. Much of his spare time was spent on or by water, itself glass-like, and in search of the secretive elements—this time panfish, trout and marlin—lurking within. His whole career, though, thanks to the support of Corning, had been conducted at a similarly leisurely pace: a journey by patient microsteps to the “Centre of the Crystal Ball”, as he called his autobiography, punctuated by moments of delight and surprise at what glass could become, given half a chance. And so it must have been, he reflected, for those other alchemists, bent over their alembics long ago.