Invention Of Ovenproof Glass

At one time glass was too delicate to put in an oven, but the invention of heatproof glass by German experts in the late 19th century, and its subsequent development in America as Pyrex® cookware, brought about a culinary revolution.

Today we take ovenproof glassware for granted, but at one time the idea of placing glass dish in an oven would have seemed incredibly foolish. Even after the invention of a suitable heatproof glass, the idea of using it for cooking seemed so improbable that Pyrex ovenware came about almost by accident.

Towards the end of the 19th century, Otto Friederich Schott, Carl Zeiss and Ernst Abbe (all Germany) established a specialist glassworks called the Glastechnische Versuchsanstalt at Jena, Germany. Their factory became renowned for the production of high-quality lenses, microscopes, binoculars and other optical equipment. It later became the Jena Glassworks of Schott & Associates and, from 1919, part of the Carl Zeiss Foundation. In 1884 the trio developed a new type of heat- and chemical-resistant glass, known as borosilicate glass from its main ingredients, boron oxide and silica.

Then, in 1912, J.T. Littleton, Eugene Sullivan and William Taylor (all USA) of Corning Glass developed the Germans' borosilicate glass into an improved heatproof glass known as Nonex, which was at first used purely for industrial purposes. Legend has it that the idea of using this glass for ovenware came about in 1913, when the wife of one of the Corning technicians baked a cake in a battery jar made from Nonex. As a result, the company was inspired to develop the first ovenproof glass for domestic use, which was launched in 1915 under the trademark Pyrex.

Not only was the glass inventive, but so were the designs - a 1937 advertisement for a Pyrex casserole dish announced: 'It's like getting three dishes in one!' The advertisement went on to explain how the lid and the base could be used as separate dishes or used together as: 'The Complete Casserole. Modern, streamlined, practical... You can see the food cooking in "Pyrex" Brand dishes.'

Source - The Book of Inventions by Ian Harrison