The encyclopedia · Product & Design · Product decision · 1892–1907
German glassblowers turned Dewar's lab flask into the Thermos in 1904
Dewar's 1892 vacuum flask stayed lab equipment until two German glassblowers patented a metal-cased version in 1903 and named it Thermos in 1904.
Thermos GmbH
The solution
In 1892 Scottish scientist James Dewar invented the vacuum flask to hold liquefied gases at very low temperatures: a glass bottle inside a larger glass bottle, with the air between them evacuated so the contents stayed at temperature. It was a lab instrument, and Dewar — who had fallen out with Alfred Nobel over another patent — never patented it.
The German glassblowers Reinhold Burger and Albert Aschenbrenner, who made Dewar's flasks, saw a different market. In 1903 they patented a domestic vacuum flask with a protective metal casing, and in 1904 they ran a contest to name the product: a local resident offered 'Thermos,' from the Greek word for heat, and Thermos GmbH was born.
Portable hot-and-cold storage proved immediately useful. American businessman William B. Walker met Burger in Berlin, bought the U.S. patent rights and founded the American Thermos Bottle Company in 1907 with a Brooklyn plant — turning a cryogenics tool into a household word and, eventually, a generic one.
Why it worked
- Dewar's flask was unpatented, so the design was free to use
- A metal casing made the fragile glass bottle practical for everyday use
- The name 'Thermos' branded the category itself
- Keeping liquids hot or cold on the go had obvious mass appeal
What can be applied
An invention nobody patented is free for the taking: Dewar left the flask unprotected, so whoever packaged it for ordinary use owned the market — the business was the packaging, not the physics.
Aftermath
'Thermos' became a generic dictionary word for vacuum flasks, and the company expanded to the U.S. in 1907. The vacuum flask remains a standard consumer product for keeping drinks and food hot or cold on the go.
Sources
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