Recent Simultaneous Measurements Of The Solar Constant Of Radiation At Mount Wilson, California, And

ASTRONOMY: C. G. ABBOT 383 explanation through its relation to the deeps of the North Atlantic. Oceanica may be intelligently linked up and explained. If the establishment of isthmian connections be explicable according to the discoidal theory, can their subsequent submergence also be accounted for?-According to the discoidal theory, the source of very large masses of igneous rocks lies in the base of the discs. The extrusion of the melt is accompanied by subsidence of the central portion of the disc, which in turn and in time may be succeeded by slipping down of the elevated margins. The mechanism appears to be workable. It requires, however, fuller elaboration than can here be given to elucidate it. These concepts are obviously consistent with the permanency of oceanic basins and continental masses. In addition to the tests proposed by these general questions, the theory should be tried by the more exacting requirements of the mechanics of deformation. This has been attempted and not without reasonably satisfactory results. The structure of the Pacific ranges of California has been discussed before the Geological Society of America and the LeConte Club of California, and the paper will shortly be offered for publication. 1 Abstract of a paper presented to the iGeological Society Meeting of the Cordilleran Section. of America at the Pasadena RECENT SIMULTANEOUS MEASUREMENTS OF THE SOLAR CONSTANT OF RADIATION AT MOUNT WILSON, CALIFORNIA, AND CALAMA, CHILE BY C. G. ABBOT SMITHSONIAN INSTITUTION, WASHINGTON Read before the Academy, April 29, 1919 For the past fourteen years, with the exception of the year 1907, the Smithsonian Astrophysical Observatory has observed the solar radiation at its station on Mount Wilson, California, altitude 5700 feet. Measurements are made by means of the pyrheliometer and spectro-bolometer at diffe