Condensing pump used by Joule with a gas cylinder for experiments on the condensation of air in 1844. Joule described it thus: 'consisting of a cylinder of gun metal and of a piston fitted with a plug of oiled leather, which works easily, yet tightly, through a stroke of 8 inches. The cylinder is 10 1/2 inches long, 1 3/8 inch in interior diameter' Condensing pump used by Joule with a gas cylinder for experiments on the condensation of air
