II. On the alleged slipping at the boundary of a liquid in motion

Abstract

The experiments of Helmholtz and Piotrowski on the oscillations of a metal sphere suspended bifilarly, and filled with various liquids, gave finite values to the slipping coefficients. The inside of the sphere was gilded and polished, and the value obtained for the coefficient λ was, in the case of distilled water, 2·3534 mm. From some experiments of Girard on transpiration through copper tubes, Helmholtz deduces the value λ = 0·3984 mm. for water flowing past a copper surface.