With the experimental data collected in a B-29 airplane and given in an earlier report, an attempt is here made to correlate several of the well-known geomagnetic effects found in cosmic rays. First, evidence is presented to show that, within the uncertainties of the experimental data and the existing calculations on the behavior of charged particles in the magnetic field of the earth, there are few if any negative primary particles in the momentum range 7 to 23 Bev/Zc compared with positives. Second, under the assumption of no primary negative particles and by correlating experimental data on the latitude effect at different zenith angles with the zenith angle effect in the east-west plane at the equator, it is possible, with the help of calculations of Vallarta et al. at the equator, to determine curves of minimum momentum for the primaries as a function of geomagnetic latitude. It is thus possible to plot curves for intermediate latitudes where the calculations are extremely difficult and have not been carried through in detail except in certain special cases. The results are independent of any assumed momentum distribution of, or the magnitude of charge carried by the primary particles.

• Received 27 February 1950

DOI:https://doi.org/10.1103/PhysRev.78.674