Note on hard showers

Abstract

Summary Arguments are given to show the following: o 1) The distinction between extensive and narrow showers seems to be non-essential. It reduces in essence to the generation of showers far awav and nearby. Both types seem to be produced by the same process i.e. catastrophic collisions and the apparent difference is merely introduced by the particulars of the experimental coincidence technique of shower registration. 2) It is to be expected that even this apparent difference will not be found above a height of about 4 km. For the determination of a, the variation of showers generated nearby and the study of bursts seem to be the most promising methods. 3) In all determinations of a published thus far the decrease of effective aperture of the primaries with increasing atmospheric depth has been neglected. Thus a might well become 10% too high. 4) The variation of hard showers generated far away, the so-called extensive ones, do not seem suitable for the determination of a.