A series of experiments was conducted in Phase II of Project Cowboy in which tourmaline crystal transducers, located at 3 to 50 ft from tamped high- explosive detonations, detected dynamic elasto-plastic stress waves generated in salt. The detonations occurred 110 ft below the 800ft working level of the Carey Salt Mine, near Winnfield, Louisiana. These experiments were designed to measure dynamic stress conditions resulting from explosions in earth media, of which little is known at present, and to provide data for comparative calculations on seismic disturbances from tamped explosions and from explosions in large underground cavities. Elastic stress waves of 1 kilobar magnitude were observed with velocities of about 15,000 ft/ scc. Inelastic stress waves up to 6 kilobars in magnitude were measured. Velocities for these waves were in the range 9000 to l2,000 ft/sec. (auth)