A method for the experimental determination of the sliding friction coefficient between a liquid and a solid

The assumption usually met in fluidodynamics is that the relative velocity usub(r) of the liquid with respect to the wall is zero. H. Lamb considered the possibility of slipping by introducing a ''sliding friction'' coefficient β which has been always tacitly disregarded. The high sensitivity now achieved in the viscosity measurements makes possible, in principle, an interesting check of Lamb's hypothesis. The present paper suggests a way to give an answer to the problem, or at least, to fix a lower limit for 1/β. (author)