In 1913, a Corning physicist baked a cake in a cut-down railway-lantern glass jar; the experiment helped lead to heat-resistant cookware

The origins of one of America’s best-known cookware brands began with a railroad safety challenge rather than a kitchen problem. One well-known American cookware company was not created because of any cook or any housewife; rather, it was engineers who wanted to solve a railroad safety problem. Let’s go back to the beginning of the 20th century when Corning scientists invented a heat-resistant glass that was able to protect railway signal lamps against possible breakage due to quick temperature changes. The invention proved to be extremely efficient, and demand for replacement lamps decreased. The National Inventors Hall of Fame explains how this quest led Eugene Sullivan and fellow scientist William C. Taylor to develop Pyrex cookware, transforming an industrial glass innovation into one of the most familiar products in American kitchens.

From railroad safety to an unexpected kitchen experiment

The story began several years before the first Pyrex pie plate reached store shelves. In 1908, Eugene Sullivan came to Corning Glass Works to start what is considered the first industrial research laboratory in America. One of the problems faced by the company at that time was a dilemma faced by railroad companies throughout the country. Glass globes that were put in signal lanterns on the trains often cracked when exposed to sudden changes of temperature.


Together with the chemist William C. Taylor, Sullivan refined the formula of borosilicate glass to create a product that Corning called Nonex. Because this kind of glass expands very little when it is heated or cooled, it became much more resistant to thermal shock compared to regular glass. Soon, the railroads began using Nonex lantern globes, which reduced breakages. However, this made another problem for Corning because they didn't need replacements anymore. That is why Corning's scientists looked for other places where this kind of glass could be useful.

The chance came with a normal accident at home. In 1913, Jesse T. Littleton, a Corning physicist, talked about the company's problem with his wife Bessie because one of her baking dishes made of ceramics had cracked in the oven. It was not clear whether heat-resistant Nonex glass would stand the heat better than conventional cookware. So Jesse took the bottom part of a Nonex battery jar, and Bessie baked a sponge cake in it. The experiment was very successful. The cake baked evenly, came out of the glass easily, and proved that the industrial glass had another destiny. Corning explains that Bessie's successful baking experiment convinced researchers to continue refining the glass into a product suitable for cooking, leading to the first commercial Pyrex pie plate.

Reinventing industrial glass for everyday homes

While the kitchen test was a success, the Nonex glass could not be used for food preparation because it included lead. This meant that Sullivan, Taylor, and the Corning scientists had more science to do before Nonex could become cookware. They redesigned the borosilicate glass, taking out the lead but retaining the same thermal resistance that made Nonex so successful in railroad lanterns. The new glass was cookware-safe but still able to resist thermal shock. Instead of introducing a whole line of cookware, Corning introduced one piece—the pie plate. It is commonly accepted that the name “Pyrex” came from the first pie plate combined with the Corning habit of ending their glass products with “ex”.

From a single pie dish to a household name

The release of the first Pyrex pie plate in 1915 became an important milestone for Corning Glass Works. The invention that had solved problems with railroad lanterns evolved into a line of ovenware suitable for everyday cooking. The glass baking dishes gave consumers the ability to see how their food was browning while being heated because they resisted rapid temperature fluctuations that could cause ordinary cookware to crack.

The company understood that to encourage customers to cook using glass cookware, some persuasion was necessary. Corning worked with home economists, cooking schools, and writers to prove the benefits of the new products. Special recipes were invented and tried for glass cookware, and the ads stated that Pyrex was durable, clean, and efficient. As more households purchased the product, the company began producing other items such as casserole dishes, loaf pans, custard cups, and measuring tools.

Why borosilicate glass changed cooking

The invention of Pyrex was made due to the development that took place in materials technology and not only by means of marketing. Regular glass expands tremendously when heated, and then contracts again when cooled, which makes it easily crackable if there is any temperature change. But borosilicate glass has a specific structure that does not expand much, and it can easily take the transition from the heat of the oven to the coolness of the kitchen better than ordinary glass of those days.

The unique quality of the material made it useful for things other than cooking too. Scientific laboratories found Pyrex useful for beakers, flasks, and other tools used in scientific experiments because the glass would withstand being repeatedly heated without cracking up easily. Thus, one engineering achievement connected home cooking with science in one piece of glass. Eventually, Pyrex became a common sight in laboratories as well as in American kitchens.

From the kitchen to scientific research

Even though Pyrex gained popularity as cookware for the kitchen, its usefulness went well beyond the kitchen as well. In fact, due to the characteristics of being heat-resistant and chemically inert, this type of glass was widely used as lab glassware in various schools, hospitals, and other research establishments worldwide. Thus, what once started as an innovative invention meant to protect railway lanterns from high temperatures resulted in the development of new tools and materials in various industries. From a pie plate in 1915 to its continued use in cookware and scientific applications, this material has proven useful in many ways.