Vacuum flask (1892) | Dewar invents in the forerunner to Thermos

" The mirrored dome of an upturned Dewar flask is a thing a beauty, which every chemist should own. " Andrea Sella, Royal Society of Chemistry 

Needing a container capable of storing liquid form of chemicals, Scottish physicist and chemist James Dewar (1842-1923) designed the vacuum flask that came to bear his name.

In 1892, Dewar put one flask inside another and the sucked out the air between the flasks creating a vacuum. The double-walled vessel proved a superior insulator and perfect for a focus of Dewar's low temperature phenomena, and subsequently led to the inventions of the thermos flask.

A reproduction of one of Dewar's 
experimental flasks, cut away to 
show the space between the two walls.

For a few years, Dewar's flasks were on laboratory shelves not store shelves. The flasks' commercial potential was recognized by a glass blower employed by Dewar to fabricate the flasks, Reinhold burger. He realized that Dewar's flasks could also prove useful for keeping food and drink either hot or cold. After adapting Dewar's flasks for household use, Burger obtained a German patent, founded Thermos GmbH and began selling "thermoses" in 1904. The name Thermos (coming from the Greek therme meaning hot) was suggested by a Munich resident in a competition. Burger received a U.S. patent in 1907, which described the flask as "a double walled vessel with a space for a vacuum between the walls."

Dewar never sought a patent for his flask and he lost a court case attempting to prevent Thermos from using his design. However, he gained many awards for his contributions to science. He was the first to produce hydrogen in liquid form and to solidify it, and he coinvented the smokeless gunpowder, cordite, with Sir Frederick Abel. Dewar was also knighted the same year the Thermos flask went on sale.

Reference:-1001 Inventions That Changed The World