536 SCIENTIFIC RECORD FOR 1883. 



from the principle of the preservation of areas, which shows that the 

 radius rector projected upon the plane of the equator will describe 

 equal areas in equal times. (Z. O. G. M., xvn, p. 7C.) 



Dr. P. Andries describes some pretty experiments in producing steady 

 and progressive whirling movements in the atmosphere and in the 

 water. He infers that a strong, horizontal current at some distance 

 above the earth is sufficient to produce in a mechanical way horizontal 

 and vertical whirlwinds in a lower quiet stratum of air. The low ba- 

 rometer within a hurricane or tornado is, he concludes, the consequence, 

 not the cause, of the whirlwind motion. There is a continual inflow of 

 fresh air taking up the whirling motion while other air is pushed out to 

 make room for it ; an anti-cyclone lies above each cyclonic movement. 

 The progressive movement is due to upper currents of air. His theory 

 requires that every tornado should be accompanied by another simul- 

 taneously pursuing a parallel track and having its rotation in an oppo- 

 site direction. [Both these conditions are utterly opposed to the facts 

 collected in Fiuley's memoirs on American tornadoes.] (Z. 0. G. M., 

 XVII, pp. 307 and 385.) 



Richter gives the results of some observations for four years, 1877 to 

 1880, of the directiou of the cloud movements at Ebersdorf in Silesia. 

 He distinguishes the direction of the motion of lower clouds in the morn- 

 ing hours C to 10 A. m., and the afternoon hours to 4 p. m. The per- 

 centages of movemeuts from the north and northwest were apprecia- 

 bly less in the afternoon than in the morning. Those from the southwest 

 and west were greater in the afternoon. Any group of three or four 

 months showed the same phenomenon; the southwest and west move- 

 ments being on the whole about 8 per cent, more frequent, while the 

 northwest and north were 9 per cent, less frequent than the average, 

 so that during the day there was a general shift in the lower cloud 

 directions towards the south or backward. On the other hand, the 

 comparison of the afternoon observations with those taken between 

 5 and 10 P. M., shows nearly equal tendency of cloud direction to shift 

 back toward the north. A part of this shift may possibly be due to the 

 high mountains east and west of the station. The observation of the 

 upper clouds show no such daily period, as they retain nearly the same 

 direction throughout the day. (Z. 0. G. M., xvn, p. 245.) 



Colding, in an elaborate study of the storm of November, 1872, and 

 its effects in Denmark, deduces the effect of the wind on the waters of 

 the North Sea. He shows the piling or accumulation of water pressed 

 forward by winds to be represented by the formula 



V=-2579 % /f H ,or A =^( 2 J 7 y 

 where V equals wind velocity in meters per second, H the depth of 

 the sea in Danish feet, h the piling up for a distance, I or = the accumu- 

 lations per unit of length. The rise of water on the southern coast of 



