Author Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt:...of the heat which is carried across the equator by the strong southeast trade drift.1 1 The mean temperatures of both hemispheres as computed by different investigators are as follows:--Northern hemisphere: Dove, 15-5; Schoch, 15-1; Ferrel, I5-3; Spitaler, 15-4. Southern hemisphere: Sartorius von Waltershausen, 15-8; Schoch, 14-9; Ferrel, 16-0; Hann (1882), 15-4; Spitaler, 14-8; Hann (1896), 14-7. (W. Schoch: Darstellung der mittleren Jahrestemperatur als Funktion der geographischen Breite und Langc, Zurich, 1856. Based on Dove's isothermal charts. William Ferrel: Meteorological Researches for the Use of the Coast Pilot, I., U.S. Coast and Geod. Surv., Washington, 1877. Based on Buchan's original isotherms. J. Hann: "Ueber die Temperatur der siidlichen Hemisphare," S. W. A., LXXXV., 1882, Pt. II., 6-29). It seems well to include here a purely theoretical computation of the mean temperature of the earth's surface, and to compare this with the results of observation. Christiansen has made the following calculation. It is assumed that, of the radiant energy which comes to the earth from the sun, 2 calories (per sq. cm. per minute) are absorbed and applied to raising the temperature. This assumption is consistent with the results of observation. (Langley's solar constant is 3, of which value about one-half, i.e., 1-5, reaches the earth-s surface with a zenithal sun, and the diffuse radiation from the atmosphere can easily supply enough to make 2 effective calories.) If this assumption is made, the amount of heat effective in warming the earth, received by the latter, is 2-=-4. The whole surface (S) receives the heat of a pencil of radiation whose cross section at the earth is a great circle of the earth. If we take Stefan's law of radiation, and if th...