The achievement of a sustained magnetic field of 152 000 gauss, the strongest ever produced, has been reported by the Naval Research Laboratory. The field was produced at NRL's magnet facility in Washington, D.C., with a solenoid magnet incorporating basic design principles described by Francis Bitter of the Massachusetts Institute of Technology in 1938, combined with improvements developed at NRL during the last fifteen years. The present figure is 26 kG greater than the previous record, established a year ago at MIT's Lincoln Laboratory with a solenoid designed by H. H. Kolm.