Scientific Serials

Abstract

THE American Meteorological Journal for July contains the following articles:— On the appearance and progressive motion of cyclones in the Indian region, by W. L. Dallas. The object of the inquiry is to see whether the cyclones of the Indian Ocean originate from the unequal distribution of temperature over and above the earth's surface. The author favours the assumption that cyclones are a production of the upper atmosphere, and thinks that the evidence, although far from conclusive, goes to show that (1) cyclonic storms descend from and retreat to the superior layers of the atmosphere; (2) the whirl may travel along in the upper atmosphere, giving only faint indications of its presence at the earth's surface; (3) the movements of cyclones agree generally with what may be supposed to be the movements of a superior layer of the atmosphere.—S. A. Hill, a memoir, by Edna Taylor Hill.—The eye of the storm (conclusion), by S. M. Ballou. The cause of the clearness of the eye is attributed by the author to the deficiency of the air at the outer edge of the calm, owing to the deflective force of the earth's rotation and the upward and outward movements of the air before reaching the centre; the deficiency being supplied by a gradual settling of the air over the whole area, thus dissolving the cloud stratum and showing the blue sky. The author admits that the discussion of the subject shows the need of more observations concerning the phenomenon.—Recent efforts towards the improvement of daily weather forecasts, by H. Helm Clayton. Tne author states in a clear and interesting form the various rules which have hitherto been established, and draws attention to a law of averages discovered by Francis Galton, which might with advantage be used in weather forecasting, for, although only applied by Mr. Galton to heredity, it is probably universal. For example, if a storm during a given twelve hours has moved with a velocity below the average, the probability is that it will move with a velocity one-third nearer the average during the next twelve hours.—The other articles are—on the sea breeze, by W. C. Appleton, and temperature sequences, by H. A. Hazen, being an inquiry as to whether, if the temperature has been high or low for a certain period, we may anticipate the contrary condition shortly. The inquiry does not seem to have led to any result which could be turned to practical use.