The Thermos Flask, also known as a vacuum flask, is a vessel mostly used for storage of hot or cold liquids. It uses the principle of a vacuum to keep the contents warmer or colder than the surrounding environment. It consists of two vessels and one is placed inside of the another. The small space between the vessels is evacuated of any air allowing a vacuum to form. This vacuum stops the transfer of heat between the middle container to the outer container and then into the outside environment. They are generally made of glass, plastic, metal and foam. Thermos flasks have a reflective coating that further diminishes heat transfer.
The inventor of the thermos flask
The original thermos flask or vacuum flask was invented in 1892 by a Scottish scientist named Sir James Dewar. Sir James Dewar needed a way to store liquid oxygen at temperatures below -183 C. This was difficult and often meant that much time was consumed in recreating the liquid oxygen for the next experiment. Sir James Dewar came up with his own unique solution, the vacuum flask. Dewar’s original design was made of two glass chambers with the vacuumed space in between. This was then coated with a reflective coat of silver to minimize heat transference. The invention of the vacuum flask allowed Sir James Dewar to become the first person to produce liquid and solid hydrogen. He then went on to co-invent cordite, a smokeless gunpowder.
The adaptation of the original vacuum flask
Sir James Dewar was not interested in the application of his vacuum flask outside of the science laboratory. However, one of his former pupils Rheinhold Burger could see the potential of the invention in other arenas. He encased the fragile glass vessels inside of a protective mental casing and secured it with rubber mountings. In 1904 Burger sold the vacuum flask to a German company who held a competition to name the item. The winning name was the Thermos flask and that is what they are most commonly known to this day.