Abstracts of Technical Articles by Bell System Authors (01 April 1941)

General solar activity and terrestrial disturbances is quite evident, the association of individual storms with specific sunspot groups has never been very satisfactory. Disturbances sometimes have occurred when no sunspots were visible and at other times large sunspots have been unaccompanied by any abnormal disturbances. A possible explanation of such anomalies may lie in longer transit times for the disturbing solar emission than is usually assumed. Some indication is given in this paper that these transit times may range from periods as short as only one or two days to as much as three months. 

The corresponding velocities for the above transit times are of the order of 2000 and 20 kilometers per second. Curves show the approximate relation between the angle of emission, velocity, day of emission, and the days intervening between the passage of a spot through the central meridian of the sun and the corpuscular encounter with the earth. The Efcct of the Earth's Curvature on Ground-Wave Propagation."1 CHARLES R . BURROWS a n d MARION C . GRAY.