Abstract
Cosmic-ray intensity-time variations recorded in the lower atmosphere by one neutron detector (D-1, Climax, Colorado) and three ionization detectors (Freiburg, Germany; Cheltenham, Maryland; and Huancayo, Peru) are compared. Irregular intensity variations characterized by time parameters of 27 days and 24 hours are shown to occur in coincidence in the records of both types of detectors. It seems reasonable to ascribe correlated neutron and ionization intensity variations to a common origin.