A low friction apparatus for measuring the compression of articular cartilage during static loading and subsequent recovery under conditions of immersion is described. The instrument system employed a specially designed balance lever and sensing transducer that recorded load and displacements as a function of time. Unlike the findings of past experiments conducted in air, measurements made in Hanks' balanced salt solution disclosed restitution of the compressed cartilage, following removal of loads up to 82.5 gm/mm², to its original thickness. The measurements were affected by the tonicity of the immersion medium. The so-called imperfect elasticity of articular cartilage previously reported in the literature thus is an artifact.