Louis-Paul Cailletet (21 September 1832 – 5 January 1913) was a French

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

and inventor.

Life and work

Cailletet was born in Châtillon-sur-Seine,

Côte-d'Or Côte-d'Or (; literally, "Golden Slope") is a département in the Bourgogne-Franche-Comté region of Northeastern France. In 2019, it had a population of 534,124.Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Si ...

, Cailletet returned to Châtillon to manage his father's ironworks. In an effort to determine the cause of accidents that occurred while tempering incompletely forged iron, Cailletet found that heating the iron put it in a highly unstable state, with gases dissolved in it. He then analyzed the gases from

blast furnaces A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheric ...

, which helped him understand the role of heat in the changes of states (phases) of metals. This brought him to the work of liquefying the various gases. Cailletet succeeded in producing droplets of

liquid oxygen Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an app ...

in 1877 by a different method than

Raoul Pictet Raoul-Pierre Pictet (4 April 1846 – 27 July 1929) was a Swiss physicist. Pictet is co-credited with French scientist Louis-Paul Cailletet as the first to produce liquid oxygen in 1877. Biography Pictet was born in Geneva. He served as profe ...

: He used the Joule-Thomson effect; oxygen was cooled while highly compressed, then allowed to rapidly expand, cooling it further, resulting in the production of small droplets of liquid oxygen.For biographical and scientific details, see Among his other achievements, Cailletet installed a 300-m/985-ft high manometer on the Eiffel Tower; conducted an investigation of air resistance on falling bodies; made a study of a liquid-oxygen breathing apparatus for high-altitude ascents; and developed numerous devices, including automatic cameras, an altimeter, and air-sample collectors for sounding-balloon studies of the upper atmosphere.

References

{{DEFAULTSORT:Cailletet, Louis-Paul 1832 births 1913 deaths People from Châtillon-sur-Seine French physicists Members of the French Academy of Sciences Mines ParisTech alumni

Life and work

See also

References