This paper describes apparatus for measuring internal friction which satisfies the conditions (a) low induced stress amplitude to preclude any plastic flow of the specimen, (b) ability to install specimen within a few minutes after treatment, (c) rapidity of measurement, at a rate of ten to twenty per minute, (d) accuracy of at least one percent.Longitudinal vibrations are induced by an eddy‐current drive, similar to one previously described in the literature, satisfying (a) and (b). Conditions (c) and (d) are obtained by measuring the decay time of free vibrations using vacuum tube trigger circuits and a counter chronograph. Satisfactory measurements can be made with push‐button rapidity and simplicity.