Cosmic-Ray Experiments at High Altitudes over a Wide Range of Latitudes

Abstract
A number of experiments made in a B-29 on the properties of cosmic rays are herein reported. These include the latitude effect of the following, performed along the 80th geographic west longitude from 64° geomagnetic north to the geomagnetic equator, all at a constant pressure altitude of 30,000 ft. (3.10 m of water equivalent): (1) Intensity at the vertical without and with lead absorber; (2) intensity at 45° West and 45° East both without and with lead absorber; (3) total ionization intensity; (4) extensive showers. Also measured at 48° North and at the geomagnetic equator were the following: (1) Zenith angle effect both without and with lead absorber; (2) intensity vs. air pressure without and with lead; (3) extensive showers vs. air pressure; (4) local showers. In addition to the above the variation in azimuth of the cosmicray intensity was measured with the various telescopes tipped at 22½°, 45°, and 67½° to the vertical at an elevation corresponding to 2.35 m of water equivalent at the geomagnetic equator. Two lead thicknesses were used, 10 and 20 cm, inserted between the counter trays. These experiments throw new light on the nature of the primary radiation and on the interaction of the primary particles with the matter through which they pass.