We report new negative results for detection of gravitational radiation with a 500-kg, 1637-Hz detector of demonstrated sensitivity and detection efficiency. These results are compared with numerous detections reported by Weber. We conclude that those detections did not arise from gravitational radiation. Furthermore, gravity waves (or other impulsive excitations) could not have produced data with a coincidence peak as narrow as that published in September 1973. © 1974 The American Physical Society.