On the Showers of Rays Which Produce Bursts of Cosmic-Ray Ionization

An expression for the probability that a shower of a given number of rays will discharge a number of Geiger-M\"uller counters is derived and experimentally verified by observing the bursts of ionization in an ionization chamber and the simultaneously occurring discharges of three counters placed under the chamber. An estimate is made of the relative importance of the contributions of showers of various numbers of rays to the counting rate of counters placed out of line. The view that there is no sharp distinction between small showers as observed in cloud chambers and the very large showers which produce the bursts of ionization, or St\"osse, in ionization chambers is emphasized. The results have a significant bearing upon the interpretation of counter experiments on showers.