The origins of the modern thermos can be traced back to the laboratory of Sir James Dewar, a 19th-century Scottish scientist, where he experimented with low-temperature materials. Producing liquid oxygen at temperatures below -183 C, the storage problem proved particularly challenging and in 1892 Dewar developed his own solution, the vacuum flask.
His invention consisted of two glass-walled chambers separated by vacuum, which prevented air currents from moving heat in or out, and a silver coating created a reflective layer to reduce additional heat transfer by radiation. Dewar built on his sub-zero experience, becoming the first person to produce liquid and solid hydrogen and later to co-invent cordite, a smokeless gunpowder. Eventually knighted in 1904 in recognition of his significant contributions to science, the full potential of his vacuum flask had not yet been realized.
Meanwhile, Rheinhold Burger, one of Dewar’s former students, realized that the vacuum bottle could have commercial applications. He improved on the fragile design by enclosing the glass chamber in a sturdy metal casing, secured with protective rubber mounts, and in 1904 he sold the idea to a German company of glass blowers. Such a novel invention deserved an impressive name and soon a contest was launched to find one. The eventual winner, a resident of Munich, could never have imagined that his choice would remain a household name in the 21st century. Derived from the Greek word for heat, “therme,” the thermos had arrived.
Production was initially slow and expensive, as each glass container was hand-blown by skilled craftsmen and only a small number of jars could be completed in a day. Despite this, Thermos expanded, becoming an international concern and in 1911 a London-based subsidiary made a major advance in the mechanization of flask production. Production increased, prices fell, and the vacuum bottle became a must-have item with its miraculous claim to keep liquids hot for 24 hours or cold for three days.
An intense marketing campaign declared it “the bottle of the 20th century made for modern people” and “a must for every modern home from Pole to Pole”. Backed by Earnest Shackleton on his voyage to Antarctica and the Wright brothers on their plane, the Thermos was taken on many famous expeditions, further increasing its status.
As the hip flask increased in popularity, new products became available, including the classic pint-sized “Blue Bottle” and the “Jumbo Pitcher,” a gallon-sized jug for storing food. The development of stronger Pyrex jars in 1928 led to the creation of huge 28-gallon containers. These were used in stores as ice cream parlors or to store frozen fish, although commercial refrigeration took over in the 1930s.
World War II brought great changes to the Thermos Company in Great Britain. Almost all of its resources went to military demands, as the vacuum flask became standard issue in wartime. It has often been claimed that every time a thousand bomber planes went out on a raid, more than 10,000 vacuum flasks went with them. One former pilot recalls how supplies were scarce, but “my kit always consisted of thermoses of tea and coffee and packets of sandwiches.”
Even today, it seems to be valued by militaries around the world. A soldier, recently on duty in Afghanistan, describes how the Russians customize their Jeeps. “The commanders make them plush curtains, padded seat covers, fans, and beverage cabinets (which always contain a thermos of black tea).” After World War II, production refocused on civilian requirements, and the populace seemed interested in renewing their familiarity with the little miracle.
Already established as a household favorite for food and drink storage, the thermos had wider implications for science, medicine, and technology, and its list of applications continued to grow during the second half of the century. Its insulating properties proved critical in the medical field, providing an ideal medium for transporting insulin, human tissue samples, and eventually donor organs. Vacuum flask technology has also been applied to aircraft instrumentation, weather detection equipment, and is used in the nuclear power industry and international space programs.
In a rapidly developing world, this innovative product has worked hard to keep up with current trends and establish itself as an icon of the 20th century. As cheap flights made travel more accessible and new technology led to extreme sports, the introduction of the first stainless steel vacuum bottle in 1966 ensured that the bottle could meet the demands of a new generation of adventurers. . With environmental issues on the agenda today, the obvious benefits of saving energy may be the key to your survival for another century.