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What's in a thermos, and what's in a name

When the winter finally comes again, I will revert to one of my favourite seasonal pleasures - taking a break on one of my woodland walks or snowshoe hikes for a swig of hot, sugary tea from my thermos.

When the winter finally comes again, I will revert to one of my favourite seasonal pleasures - taking a break on one of my woodland walks or snowshoe hikes for a swig of hot, sugary tea from my thermos.

The fact that the bottle I am drinking from has come to be called a thermos is, in fact, the result of an interesting concatenation of technological and business history, and an ongoing sore point for the people running the Thermos company.

Had things worked out a little differently, the thermal bottle in my backpack would not have been called a thermos at all, but a Dewar flask, after the distinguished English scientist who invented it back in 1892.

James Dewar is not exactly a household name, these days, but back at the turn of the last century he was a name to conjure with, in the scientific world.

A chemist and physicist, he spent most of his career at the University of Cambridge, studying liquid gasses.

It was in the course of that study - because he needed a way to keep the gasses he was studying at something like a steady-state temperature for extended periods of time - that he came up with the idea of using a vacuum between two glass containers as a means of thermal insulation.

It was a brilliant idea, and it worked like a charm; but Dewar, intent as he was on the scientific matters of hand, never got around to patenting it - and that ended up costing him a pretty fair stack of cash.

The first “thermos” bottles, based on Dewar’s technology, were produced by the Burger and Aschenbrenner company in Germany at the beginning of the 20th century.

It was the Burger and Aschenbrenner company, in fact, that invented the word “thermos” as the brand name for their new product.

Dewar made a rather feeble attempt to regain intellectual property rights on his idea in 1904, when he filed a suit against a man named A. E. Gutman, who had been awarded British distribution rights for the Burger and Aschenbrenner “thermos” devices.

But the fact that he had never made any previous effort to protect his patent rights on the thermos idea counted against him, and his case was quickly dismissed.

A few years later, in 1907, the Brooklyn-based American Thermos Bottle Company bought up the German company and its ancillary patents, and started doing a roaring trade in selling vacuum-insulated bottles.

In its first year of business, the American Thermos Bottle Company had gross receipts of $115,000 - a pretty big pile of cash, in 1907 - and poor James Dewar (who had been knighted by then, and was now Sir James Dewar) never saw a cent of it.

But they, too, like Dewar, were more than a little careless when it came to protecting their intellectual property - in their case, in protecting their brand name of “thermos,” they had inherited from the Germans.

They were so cocky about being the dominant force in this new market that they didn’t worry about competitors using their brand name on their competing products.

To them, it was just more free advertising, and they were intent on making “thermos” a “household word.”

As time went on, though, and more competitors started eating into their un-patent-protected market share, the American Thermos company began to get more prickly about people using its brand name.

In 1952, they sued Aladdin Industries for marketing its insulated bottles as “thermoses;” but, after 10 years of legal wrangling, they lost the case, because the judge found that the word “thermos” had now become such a generic word that it even appeared in many English dictionaries.

They had succeeded so well in making the word famous that they lost control over it entirely.

That did not mean they could not remain a profitable company, of course. To this day, the Thermos Company remains a dominant force in the vacuum-insulated container market, though it is now owned by the Japanese-based Nippon Sanso Corporation.

It has diversified its product line to insulated lunch bags, coffee mugs and food containers, and actually now makes most of its money from the unrelated business of barbecue manufacture.

You can see the full line of their products now at their annoyingly Flash-infested website at

So if you, like me, avail yourself sometime this winter of the pleasure of a hot drink on a snowy forest trail, make sure you raise your thermos, whatever its actual brand name might be, in salute to the improvident genius of Sir James Dewar.

If it were not for him, this world would be a colder place.

Rick Steele is a technology junkie who lives in Whitehorse.