This report presents a survey of experimental research on transition Reynolds numbers conducted in a large number of ground test facilities. Facilities surveyed included primary wind tunnels used for aerodynamic testing at subsonic, transonic, supersonic, and hypersonic conditions. Measurements have been made on cones and planar bodies, flat plates and hollow cylinders. This report traces the work using cones, which has been more extensive. The primary motivation for this research spanning nearly 20 years has been to verify the adequacy of the facilities to simulate flight conditions. This necessarily entailed the study of free-stream disturbances in wind tunnels and the role these disturbances play in altering transition Reynolds number which must be considered when scaling Reynolds-number-sensitive data. Results presented include current experimental efforts as recent as September 1976. In addition to the cited references, a bibliography of relevant publications from AEDC has been included.