Charles Cagniard de la Tour

Baron Charles Cagniard de la Tour (31 March 1777 – 5 July 1859) was a French engineer and physicist.

After this discovery, he performed quantitative measurements of the critical point of several substances such as water, alcohol, ether and carbon bisulphide.

[3] Despite several claims to the contrary, no portraits of Baron Cagniard de la Tour exist.

[4] He was the author of numerous inventions, including the cagniardelle, a blowing machine, which consists essentially of an Archimedean screw set obliquely in a tank of water in such a way that its lower end is completely and its upper end partially immersed, and operated by being rotated in the opposite direction to that required for raising water.

[3] In course of an investigation in 1822–1823 on the effects of heat and pressure on certain liquids he found that for each there was a certain temperature above which it refused to remain liquid but passed into the gaseous state, no matter what the amount of pressure to which it was subjected, and in the case of water he determined this critical temperature to be 362 °C (modern figure is 373.946 °C).