Abstract
Curves giving proton energies (a) below which no energy is allowed by the earth's magnetic field, (b) above which all energies are permitted, for all latitudes in case (a), for latitudes from 0° to 40° geomagnetic in case (b), are given for the following directions: (1) vertical, (2) zenith angle 45°, north, south, east and west azimuths. In addition the distance and angular corrections due to the longitude effect are given for geographic latitudes up to 40°.