If Scottish chemist and physicist James Dewar had only patented his 1892 invention, “a Dewar” would be the generic name for the vacuum flask instead of a thermos.
His laboratory experiments in the field of cryogenics, and his need to keep chemicals cool for longer, led him to create a double-walled glass vessel joined at the top which, when the air between the two walls was vacuumed out, kept his precious chemicals cold.
His invention was for lab use and it wasn’t until 1904 that German glassblowers Reinhold Burger and Albert Aschenbrenner saw the everyday possibilities of the invention in keeping drinks hot or cold.
They renamed the invention the Thermos and sold on the technology to Viennese inventor Gustav Robert Paalen who refined the concept and designed a range of domestic versions. His successful Thermos Bottle Company brought the simple and cheap technology to the US.
Its practical appeal to a vast range of consumers – everyone from office executives to schoolchildren, campers to construction workers – ensured its success. Eventually other manufacturers began making vacuum flasks but no other name stuck and thermos is the popular generic term.