Comparison of the Angular Distributions of the Cosmic Radiation at Elevations 6280 ft. and 620 ft.

The ray intensity $j\left(\theta \right)$ of the cosmic radiation has been studied as a function of the angle $\theta$ from the vertical on Mt. Washington, New Hampshire, elevation 6280 ft. and at a base station, elevation 620 ft. The results show a distribution less concentrated about the vertical at the higher elevation. Unless some ad hoc assumption is invoked this result is inconsistent with the intensities and absorption coefficients deduced by Millikan and Cameron as their results would lead to a considerably more concentrated distribution at the upper elevation. Integrating the ray intensities over all angles, the total numbers of rays per ${\mathrm{cm}}^2$ per sec. have been computed at the two elevations. The increase in the number of rays with elevation is less than the known increase in the ionization (Millikan and Cameron). The ratio of numbers of rays per sec. is 1.46 against 1.91 for the ratio of ionizations at the two elevations. The average 6280 ft. ray, therefore, produces 1.31 as many ions per unit path as the 620 ft. ray. This change in ionizing efficiency may perhaps be explained by supposing that the softer rays, which are more predominant at the upper level, produce more secondary rays from the walls of the ionization vessel.