National Geographic : 1890 Apr
National GeographicMagazine. and third, on their periodicity and the time of the first appear ance of the motion. Professor Russell, appropriately it seems to me, remarks regarding the landslide winds, that avalanche would be a better term than landslide as applied to winds associated with fallen masses of earth or snow. With the enormous amounts of accumulated tabulated matter, and numerous studies bearing on isolated meteorological phe nomena, it is a specially important consideration that some students pay constant attention to the investigations of the laws of storms. From such researches definite advances in theo retical meteorology may be made and fixed laws determined, which may be of practical utility with reference to the better forecasting of the weather. In the United States Signal Office, Professor Abbe has brought together the results of his studies and investigations for the past thirty years, under the title, "Preparatory studies for Deductive Methods in Storm and Weather Predictions." This report will appear as an appendix to the annual report of the Chief Signal Officer of the army. Professor Abbe finds that the source and maintaining power of storms depend on the absorption by clouds of solar heat, and in the liberation of heat in the cloud during the subsequent precipi tation, which, as he endeavors to show, principally influences the movement of the storm-centre. In this method one takes a chart showing current meteoro logical conditions, and the permanent orographic features of the continent; lines of equal density are also drawn for planes at several elevations above sea-level. On these latter, and on the lines of the orographic resistance, are based intermediate lines of flow, which show where conditions are favorable to cooling and condensation. The amount of condensation and its character, whether rain or snow, are estimated by the help of the graphic diagram. Numbers are thus furnished that can be entered on the chart and show at once the character of the new centre of buoyancy, or the directions and velocity of progress of the cen tre of the indraft and the consequent low barometer. It is hoped that this work of Professor Abbe's may be, as he anticipates, of great practical as well as theoretical value. Steps are being taken to test the theoretical scheme by practical and exhaustive applications to current work.