For millennia, we have shaped, pressed, and molded glass. Glassmakers have long experimented with recipes and processes to improve and adapt the basic formula. And modern chemistry has given rise to new glass formulas. While the exact origin of the invention of glass remains unclear, the material has led to numerous innovations in science, technology, and art.

Portrait Inlay of Pharaoh Akhenaten (-17) by UnknownCorning Museum of Glass

Glass has shaped human culture for 3,500 years. Common sodalime glass is made from soda ash (sodium carbonate) and lime (calcium carbonate).

With the rise of modern chemistry, glassmakers developed new glass formulas to glass with new desirable properties.

Harbor Lantern with Dioptric Lens (1852 - 1866) by Brooklyn Flint Glass Works, ManufacturerCorning Museum of Glass

The need for a material

In the 1800s, as railroads grew in complexity, signal lanterns became essential for safety. But extreme temperatures often shattered the sodalime glass lenses (due to thermal shock), causing unnecessary and costly accidents.

Corning Little Joe Tube Tower - Tin Pan Time Machine Project (2016) by The Corning Museum of GlassCorning Museum of Glass

Through experimentation, glassmaker Otto Schott found that adding boron made glass resistant to thermal expansion, allowing for accurate thermometers.

The Corning Glass Works began making thermometers with a similar formula using an ingenious method of pulling hot glass tubing up a tower.

Pyrex Baking Dishes (1915/1919) by Corning Glass Works, ManufacturerCorning Museum of Glass


The original Pyrex glass is a borosilicate glass. This type of glass expands and contracts less than traditional soda lime glass when heated and cooled, making it less likely to break as it heats up quickly in an oven or on a Bunsen burner in a lab, or as it cools down on a countertop.

Locomotive Headlight with Dioptric Lens (1852/1866) by Brooklyn Flint Glass Company (1840-1868), ManufacturerCorning Museum of Glass

In Corning, scientists Eugene Sullivan and William Taylor developed a different formula. They called their creation Nonex (non-expansion) glass, which performed well in railroad signal lenses.

Many borosilicate glass objects were soon made for use in the home and in the laboratory.

Bessie and Jesse Littleton (1910)Corning Museum of Glass

In 1913, Works engineer Jessie Littleton searched for new uses for Nonex.

His wife Bessie, frustrated at breaking a new casserole dish in the oven, wondered if Nonex glass might work for baking.

Pyrex Battery Jar (1950/1970) by Corning Glass Works, ManufacturerCorning Museum of Glass

Using a sawed-off battery jar, similar to this one, Bessie successfully made an evenly baked sponge cake, which Jessie shared with his co-workers the next day.

Pyrex Baking Dishes (1915/1919) by Corning Glass Works, ManufacturerCorning Museum of Glass

Bessie Littleton’s kitchen experiment led to another variation in the recipe for non-expansion glass.

The new glass became known as Pyrex, and was shaped into glass baking dishes.

Bake her a Christmas present in a "Pyrex" dish (1933) by Corning Glass WorksCorning Museum of Glass

An effective marketing campaign made Pyrex a household brand.

By 1919, more than 4 million Pyrex dishes in about 100 shapes and sizes filled American kitchens.

Warning signals in the line of vision (1927) by Moto Meter Company, Inc.Corning Museum of Glass


By the 1920s, more and more American homes boasted automobiles. Thermometers mounted on the radiator caps alerted drivers to overheating. And borosilicate glass was a key feature, preventing breakage from changing temperatures.

Corning Glass Works Clinical Thermometer Tubing Ad (1938) by Corning Glass WorksCorning Museum of Glass

A thermometer also became part of the modern household first aid kit.

Monitoring the family’s personal health safely and accurately became possible with a resilient borosilicate glass thermometer.

Pyrex Liquid Measuring Cup (1926) by Corning Glass Works and Main Plant, "A" FactoryCorning Museum of Glass


A test kitchen at Corning, run by Lucy Maltby, a woman with a degree from the newly minted field of home economics, tried out new products, evaluating their design, reviewing customer feedback, and suggesting future innovation. Borosilicate saucepans, coffee percolators, and measuring cups emerged from these efforts.

#508 measuring cup (1976-11-16) by Corning Glass WorksCorning Museum of Glass

Continued efforts at innovation led to changes to the shape of the cup, including its handle.

Pyrex ware presents new measuring cups and mix 'n' measure batter bowl (1983) by Corning Glass WorksCorning Museum of Glass

Further testing and user feedback produced a radical new design: a handle attached only at the top, allowing the measuring cups to stack.

Product Information: Technical data on Corning's #7740 glass (1963-06-19) by Corning Glass WorksCorning Museum of Glass


Pyrex became the go-to glass for lab-ware and chemical processing. Its extraordinary durability allowed engineers to design efficient processes with minimal downtime.

Organic Chemistry Kit with Original Case (1970/1989) by Corning Inc., ManufacturerCorning Museum of Glass

Borosilicate laboratory glassware like Pyrex (or Duran in Europe) withstands large temperature fluctuations without breaking.

Since it's more chemically resistant than soda lime glass it is ideal for a wide variety of chemical and other uses.

Worker strips the ladle to remove excess glass (1934)Corning Museum of Glass

The 200-inch disk

Borosilicate glass was also perfect for object literally out of this world: the largest telescope ever made.

200-inch Disk (1934) by Corning Glass WorksCorning Museum of Glass

This 20-ton, 200-inch (5-meter) disk is one of the world's largest pieces of cast glass. It served as the Hale telescope's gigantic mirror.

In 1934, the first attempt to make it failed as the casting mold broke, but the second attempt succeeded, inspiring future engineers and artists.

200-Inch Disk (2011) by The Corning Museum of GlassCorning Museum of Glass

The story of the largest piece of cast glass.

Worker strips the ladle to remove excess glass (1934)Corning Museum of Glass

Two crews spent 6 hours pouring more than 100 ladles of hot glass into the improved mold.

After 10 months of cooling in an annealing oven, the disk was ready.

Slide of workmen standing in front of 200" disk with one man inside center of disk (1935)Corning Museum of Glass

The disk traveled to California on a whistle-stop tour. After arriving at Mt Palomar, the surface was ground into shape, polished, and coated with aluminum.

The finished mirror became a key part of the most powerful telescope yet.

Eat Your Hat (1985) by Ginny RuffnerCorning Museum of Glass

Flameworking with borosilicate glass

Although artists have used flameworking (or lampworking) for centuries, they failed to gain much traction in in the fine arts until the properties of borosilicate glass allowed them to create larger-scale and more complex works. Most glasses used by artists must be kept at uniform temperatures, or they will crack and break. This limits the scale and complexity of a sculpture. Borosilicate glass tolerates temperature differences more readily than other art glasses, enabling an artist to connect multiple components into large compositions.

Marie Antoinette Sacrifices the Heart of the Nobility on the Altar of the French Republic (1790 - 1790) by Haly, Pierre, MakerCorning Museum of Glass

The individually made pieces in this scene can be very detailed, as in the case of Marie Antoinette.

Its small scale reflects the availability only of soft glass that inhibits larger productions.

Blaschka Nr. 216 (1885) by Leopold Blaschka and Rudolf BlaschkaCorning Museum of Glass

Until the invention of borosilicates, flameworkers were restricted to using soft, soda-lime glasses.

Their art and craftsmanship reached a high point with the work of Rudolph (1822-1895) and Leopold (1857-1839) Blaschka.

Woven Heaven Tangled Earth (1999 - 1999) by Plum, Susan (American, b. 1944), ArtistCorning Museum of Glass

With a hand torch from the inside out, Susan Plum (1944-) used borosilicate glass to weave this complex sculpture inspired by Mayan cosmological traditions.

Softer glasses would simply fall apart.

Lišková Anthem of Joy in GlassCorning Museum of Glass

In the late 1960s, Věra Lišková was one of the first artists to use borosilicate glass to create larger-scale sculpture.

Inspired by the form of musical notes, the sculpture communicates the emotion and energy of harmonious sound.

Family Matter (2002 - 2002) by Reynolds, Jill (American, b. 1956), ArtistCorning Museum of Glass

Jill Reynolds (1955-) uses borosilicate glass because it is more easily interconnected than other glass.

Made of small glass rods and larger, blown tubes filled with a blood-red liquid, the letters create forms resembling proteins during DNA replication.

Smallpox Virus and HIV (Human Immunodeficiency Virus) (2010 - 2010) by Jerram, Luke (British, b. 1974), ArtistCorning Museum of Glass

Luke Jerram (1974-) explores the tension between the beauty of his glass sculptures, the deadly viruses that they represent, and the global impact caused by these diseases. Borosilicate glass is ideal for this as its resistance to thermal shock allows for more complex constructions.

Eat Your Hat (1985) by Ginny RuffnerCorning Museum of Glass

Ginny Ruffner (1952-) adapted her knowledge of harder, borosilicate glasses, commonly used in scientific glassmaking, to art.

Its tolerance for extreme temperature variance allowed her to create larger compositional sculptures in which many separate elements can be interconnected.

Cross-fire series (2015) by Geoffrey MannCorning Museum of Glass

Artists exploit the ability of borosilicate glass to be partly heated and manipulated while another area is left rigid and cool.

These vessels were distorted by selectively hearing and softening specific areas to create the impression of movement.

Organic Chemistry Kit with Original Case (1970/1989) by Corning Inc., ManufacturerCorning Museum of Glass

Why boron?

Scientists have long tried to understand why adding boron makes glasses that expand and contract less under changing temperatures than the more common soda lime glass of bottles, jars, and windows. Only in the last few years has an answer emerged. In soda lime glass, sodium atoms soften the glass, making it easier to shape. But sodium also makes glass expand when it heats up. When a material gets hot, its atoms vibrate and separate more, expanding the object. Sodium atoms vibrate more than most other atoms in glass, including boron. In borosilicate glass, most of the softening is done by the added boron atoms, so less sodium is needed. As a result, borosilicate glass expands only ⅓ as much as soda lime glass.

Credits: Story

Borosilicate Glass Exhibition Team:
Marv Bolt, Curator of Science and Technology
Jane Cook, Chief Scientist
Jim Galbraith, Chief Librarian
Eric Goldschmidt, Flameworking and Properties of Glass Supervisor
Mandy Kritzeck, Digital Media Producer/Project Manager
Richard Urban, Digital Asset Manager and Strategist
Kris Wetterlund, Director of Education and Interpretation
Kathryn Wieczorek, Science Educator

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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