COSMIC RADIATION FROM THE HORIZON

A discussion is given for the production of high-energy mu -mesons from the decay of pi - and K-mesons decaying in fiight in the atmosphere. The production rate, during the earlier processes of the nucleon cascade ln the atmosphere, is abeut eight times higher for directions from 0 to 5 deg above the horizon than that for the more or less vertical direction. Suggestions are given for experiments on mu -mesons of energies 10/sup 1//sup 2/ to 10/sup 1//sup 3/ ev for intensitydepth relations and a momentum analyzer. (B.O.G.)