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Famous inventions: Safety glass

Famous inventions: Safety glassIt’s not something we often notice, but safety glass saves lives every day. Find out about the accidents that led to its discovery.

In 1903 Edouard Benedictus, a French scientist, accidentally knocked a glass flask to the floor. He heard the glass shatter, but when he looked down, he was in for a surprise. The broken pieces of the flask stayed together, more or less in their original shape.

How did it work?

Benedictus learned that the flask had recently held a solution of cellulose nitrate, a liquid plastic, which had evaporated, apparently depositing a thin coating of plastic on the inside of the flask.

As one accident had led Benedictus to the discovery, a series of other accidents directed him toward its application. In 1903, driving was a new and often dangerous hobby among Parisians. The very week of Benedictus’s laboratory discovery, a Paris newspaper ran a feature article on car accidents. When Benedictus read that most of the drivers had been cut by shattered glass windshields, he knew that his unique glass could save lives.

Seeing the point

But car manufacturers did not want to add to their costs by incorporating expensive safety glass in their windshields. It was not until the outbreak of World War I that safety glass found its first practical, wide-scale application: as the lenses for gas masks.

After automobile executives examined the proven performance of the new glass under the extreme conditions of battle, they started using safety glass in car windshields, the first of many applications.