The transfer effect in liquid He II. II. Properties of the transfer film

The results of the preceding paper show that the transfer of liquid He II takes place in a film which is formed on solid surfaces in contact with the liquid. This conclusion is quite in accordance with the observations of Rollin (1936) who attributed the high evaporation from vessels containing liquid He 11 also to the existence of a thin surface layer of liquid helium. Nothing, however, is known about the properties of this transfer film and we decided therefore to make experiments on its heat conductivity, thickness and transfer velocity. In the present paper the results of this investigation are given together with a discussion of the properties of the film and their bearing on the transfer phenomena.