Apparatus used by Ramsay and Shields for determining molecular surface energy (n.b. in all but the coiled wire spring and bulb, this is a copy made by Prof. M.W. Travers in 1931) relating to Sir William Ramsay's early researches

This apparatus is a part reconstruction of that used by Ramsay and John Shields at University College between 1890 and 1893 to determine variation of surface tension with temperature.

It has been shown by Ramsay that for gasses whose molecules dissociated, the gas laws were not followed. This experiment on liquids was designed to show that those whose molecules aggregated (instead of being unaffected by their neighbours) would not obey the analogous law relating surface tension linearly with temperature.

The diagram shows the arrangement. The height of the liquid in the capillary tube was measured at temperatures varied by boiling different liquids in the surrounding jacket.