On Penetrating Showers in Cosmic Radiation

The mean range of the radiation that generates penetrating showers has been determined in the atmosphere and in water. The results are respectively \ensuremath{\sim}120 g/${\mathrm{cm}}^{2}$ and \ensuremath{\sim}55 g/${\mathrm{cm}}^{2}$. The relation between the observed variation of the frequency of penetrating showers with barometric pressure and the absorption law in air for the shower producing radiation has been discussed in some detail. The east-west asymmetry of the radiation that generates penetrating showers has been studied and the results were found to be negative within the experimental errors. The penetrating power of the penetrating showers produced in air has been investigated. No appreciable absorption has been found when the lead protection of the counters has been increased from 18 to 28 cm.