If you've ever taken an introductory physics class, you'll know that heat is really the way we large things experience increased molecular motion. Heat is transmitted from one object to another by gazillions of molecules zinging around and jostling one another. So it seems logical that if you remove all the molecules between two objects, creating a vacuum, heat won't pass between them.

In 1892 Sir James Dewar at Oxford University put this notion to pracical use by inventing the vacuum flask. Being an academic type, he used this for research. Soon enough, though, the practical mavens got into the act, and in 1904 two German glass blowers held a contest to come up with a better name than "vacuum flask". A resident of Munich submitted "Thermos" (from the Greek therme, hot) and so Thermos GmbH¹was born. The English boffins became the first to invent a machine to make the glass fillers in 1907.

Thermos GmbH sold trademark rights to the American Thermos Bottle Company (Brooklyn, New York), Thermos Limited (Tottenham), and Canadian Thermos Bottle Co. Ld. (Montreal, Quebec). All four companies proceeded to develop the technology.

Famous users of early Thermos products included Shackelton on his trips to the antarctic and Peary on his trips to the arctic; Roosevelt in Africa; and the Wright Brothers, Amelia Earhart and Count Zeppelin in the air.

In World War II, Thermos output went almost exclusively to the military. One notable fact: every time 1000 bombers went out on a raid, 10 to 12 thousand Thermos flasks went along for the ride.

In 1960, the U.S., U.K, and Canadian companies were all purchased by the King-Seeley company to form the King-Seeley Thermos Company. In 1968 this merged company became a wholly owned subsidiary of Chicago's Household Finance Company (later renamed to Household International). Yes, the same people who brought you Thermos flasks in those days also bring you second mortgages.

Of course, the sixties were the high-water mark of conglomerate companies, and in the succeeding decades many of them were broken up. Household was no exception to this rule. In 1989, the Thermos operating companies of the U.S., U.K., Canada and Australia were bought by Nippon Sanso KK of Tokyo. Nippon Sanso had pioneered the steel vacuum bottle, an alternative to the glass bottle that didn't break when you dropped it (how many school children opened a lunch to find shards of glass in their milk?). A bit later they also bought the French and German Thermos companies, ending up with the trademark rights in 15 countries.

Nowadays the Thermos is so ubiquitous as to be practically invisible. We accept as a given that there will be one in every lunchbox and picnic box. One wonders what Sir Dewar would have thought of all this...and whether such a thing could happen again in this era of venture capitalists?