The Scottish chemist and physicist co-directed the Davy-Faraday Research Lab at the Ri from the end of the 19th Century. He is best known for inventing the Dewar flask aka vacuum flask aka Thermos.
Though he sadly didn’t profit from its widespread popularity, as he didn’t patent his invention before Thermos started using the design ()
Dewar’s flask aided his work into the liquefaction of then-so-called permanent gases like hydrogen and helium, as he could work at temperatures close to absolute zero ❄️
Whilst at the Ri he built machinery to yield high quantities of liquid oxygen, and showed that liquid oxygen and liquid ozone are attracted to the poles of a magnet
He also gave 9 series of Christmas Lectures for children! On topics ranging wide from ‘A Soap Bubble’ to 'The Story of a Meteorite’ to 'The Chemistry of Light and Photography’.
If you’ve ever wondered who to thank for your ice cold drink on a hot Summer’s day, it’s this legend: James Dewar. Dewar invented the flask that many of us use daily.
Dewar never patented his invention of the flask. Instead, it was later patented and renamed by 2 German glass blowers, who set up the Thermos company, giving the Dewar flask its common name - the Thermos! *Dewar shakes fist*
The Dewar flask works by placing a smaller flask within a larger one, and sealing them at the neck. Between the 2 vessels is a gap which has had almost all of the air sucked out to create a near-vacuum.
This vacuum reduces heat transfer between the drink inside your flask, and outside world, be it hot or cold. This is because there are too few particles in the vacuum for heat energy to transfer through it by conduction or convection currents.
