Frequency and Magnitude of Cosmic-Ray Bursts as a Function of Elevation

Measurements of the magnitude and frequency of cosmic-ray bursts have been made at elevations of 185, 1620, 3240 and 4300 meters above sea level for periods of time ranging from 189 to 336 hours, using one of the new cosmic-ray intensity meters of the Carnegie Institution. Only bursts releasing more than ${10}^7$ ion pairs are considered. The rather meager data which could be collected in these short times of observation indicate that: (1) Burst-frequency decreases with burst magnitude in a way which can be represented by a series of exponentials. (2) These large bursts contribute only a small fraction of the total ionization. (3) The magnitude of the largest burst observed increases rapidly with altitude, one observed at 4300 meters elevation exceeding ${10}^9$ ion pairs or 3×${10}^{10}$ electron volts of energy released in the chamber.