On 20th September 1842 Sir James Dewar was born.
This is a bit of a sore one for Dewar and us Scots as James is aknowdeged universally for his invention of the vacuum flask, but never thought to patent it.
James Dewar was interested in cryogenics, the science of extreme cold and in 1898 he was the first person to make liquid hydrogen, which at the time was the coldest substance ever produced.
Cooling gas to the point where it liquefies was an expensive process and Dewar needed to find a way to prevent very cold liquids evaporating while he worked with them. He built boxes insulated with cork, hay or crumpled newspapers, but none kept the liquids cold enough. Eventually he designed a double-walled glass flask and removed the air from the space between the two walls, creating a vacuum. Liquid put inside the flask stays at the same temperature because there are no air molecules through which heat can transfer.
The Dewar flask design was never patented, but two German men who discovered the commercial use for the product renamed it Thermos and claimed the rights to the commercial product and the trademark to the name so although credited with the invention Dewar made no money out of his invention by rights we should be calling the flask a Dewar rather than a Thermos the name we still use to this day. Dewar lost a court case against Thermos due to him not getting the flask patented.