Today is the birthday of Louis-Paul Cailletet, a French physicist born in 1832 who was a master at liquefying gases. Cailletet grew up working in his father's ironworks and later was in charge of the works while he conducted scientific research. In 1877 he became the first to liquefy oxygen, and soon thereafter he successfully liquefied nitrogen, hydrogen, nitrogen dioxide, carbon monoxide, and acetylene--all for the first time. Cailletet published a number of papers in French scientific journals on his liquefaction work, the production of low temperatures, the passage of gases through metals, critical points, and manometers for measuring high pressures. He also invented a device for measuring the altitude of an airplane. Cailletet died in 1913.
[Source: Britannica Online]