<p style='text-align: justify;'>Black and white photograph of Kapitsa's helium liquefier. Kapitsa's helium liquefier was in operation from 1935-1948. The main cooling was achieved by adiabatic expansion using a piston in a cylindrical volume. It was completed in 1934, a year after the opening of the Mond Laboratory. At the time, liquid helium was only available in Leiden, Toronto and Cambridge. Kapitsa was awarded the 1978 Nobel Prize in Physics for the discovery of superfluidity (but also discovered by Allen and Misener: see P777).</p>