Tantalus had a circumference of just over 9m, and, with an energy of 240 MeV, had a critical energy of slightly under 50 eV. It achieved its first stored beam in March 1968. Initial operations were very difficult, with only about 5 hours per week of usable beam, and currents of less than 1mA. Initial users came from three groups, who took turns using their commercial monochromators on the one available beamline. On August 7, 1968 this first dedicated storage ring based synchrotron radiation facility produced its first data when Ulrich Gerhardt of the University of Chicago, carried out simultaneous reflection and absorption measurements on CdS over the wavelength range 1100-2700 Å.