METEOROLOGY 313 



ascent 00.52 C. At 31o.4 the change for latitude is 0o.50, and for alti- 

 tude VP.5S. [Z. 0. G. M., XIX, p. 459.) 



194. [Similar crmputations for the Rocky Mountain and Plateau re- 

 gions of the United States, as made by Prof. W. Upton, will be found 

 in the Annual Keport of the Chief Signal Officer for 1882, and aflbrd 

 interesting bases for comparisons with the above Italian observations.] 



195. O. Doering has investigated the variability of the temi)erature 

 in the Argentine Kepublic and South America, following out tlie sug- 

 gestions in Hann's memoir of 1875, on the variability of daily tempera- 

 tures. Doering utilizes twenty years of observations at Buenos Ayres. 

 His figures give the mean variability as depending upon non periodic 

 temperature changes for the individual months and years. Sudden 

 changes upward are more frequent than falls in temperature. Ten days 

 of more than 5° change are likely to occur in a year. The north wind 

 brings the greatest rise in temperature, the southeast wind the least. 

 With regard to falls in temperature, these come with southerly winds, 

 and are preceded by northerly winds. The greatest falls in tempera- 

 ture occur without rain more frequently than with rain. {Z. 0. G. 31., 

 XIX, p. 507.) 



196. Sir G. B. Airy compares the temperatures of the water of the 

 Thames with the corresponding temperature of the air; he finds that 

 the water averages 1^.5 F. higher than that of the air according to the 

 Greenwich thermometers ; the mean diurnal range of water temperature 

 was 20.1 F. {Mature, xxvii, p. 129.) 



197. Prof, von Miller-Hauenfels states that the curvature upward 

 of the isothermal surfaces inside of a mountain mass has lately been 

 quoted as an argument against the melted condition of the earth's in- 

 terior, but it seems to him that, independent of any view that one may 

 have with regard to this source of heat, such an upward curvature of 

 the surfaces must take place under any circumstances. In general, 

 temperature increases toward the center of the earth, but with a ra- 

 pidity variable according to the time of the year. Now, according to 

 well-known laws, the transmission of heat upw^ards must take place in 

 directions normal to the surface, and these normal lines being perpen- 

 dicular to the surfaces of equal temj^erature, the latter must necessarily 

 rise up in the interior of a mountain mass. {Z. 0. G. J/., xix, ]). 297.) 



198. Prof. W. Schwalbe communicates to the Physical Society nu- 

 merous observations as to the formation of natural ice caves, and main- 

 tains that a sufficient explanation of this ijhenomenon has notyet been 

 offered. {Nature, xxvii, p. 380.) 



VI. — (a) Evaporation ; {b) Atmospheric moisture ; (c) Condensa- 

 tion, FOG, and clouds; (f/) Pain, SNOW, HAIL, drought, and 

 flood ; (e) Amount of cloudiness and sunshine. 



199. Professor Ragona, of Modena, presents the results of observa- 

 tions upon evaporation since 1872. lie finds no wellnunked daily 

 period, probably owing to some peculiarity of his apparatus. The an- 



