In the accompanying tables are contained the results of some experiments respecting the rate at which aqueous vapour condenses on a cold surface.

These results are not so consistent as could be desired, but having been obtained by a definite and carefully-conducted process, they may claim at least to be received as approximately true.

In planning the experiments, it was assumed that c = m (f“ − f“ʹ), where c is the weight of moisture which is condensed on a surface of given area in a given time; f“ the tension of vapour at the dew-point; f“ʹ its tension at the temperature of the condensing surface; m a coefficient varying with the velocity of the current of air.