What is the difference between dogs and marine biologists?
One wags a tail, and the other tags a whale.
Liquifaction of oxygenIn 1879, the liquefaction of oxygen was announced by Raoul Pierre Pictet (1846-1929), a Swiss chemist and physicist, by sending a telegram to the French Academy: Oxygen liquefied today under 320-atm and 140 degrees of cold by combined use of sulfurous and carbonic acid. French physicist Louis Cailletet made a similar announcement two days later. Pictet's early interest was in ice-making machines. Later, he studied extremely low temperatures and the liquefaction of gases. Both Pictet and Cailletet used both cooling and compression to liquefy oxygen but they achieved this using different techniques. Pictet's method had an advantage in that produced the liquid gas in greater quantity and was easier to apply to other gases.[Image: part of a Pictet machine to cool down glycerine, which was pumped through a piping system in the first artificial skating track:] |
