B. TERRESTRIAL PHYSICS AND METEOROLOGY. 89 



finds that Loth the southeast and northwest storms ex- 

 perienced at that place are much modified by the influence 

 of the Alps. The southeast, or fohn, wind has, at all seasons 

 and at all points, a notably high temperature, the exception 

 only being in the three summer months, in which the fohn 

 decidedly depresses the temperature. In the winter and 

 summer the temperatures of the southeast and northwest 

 storms are nearly the same, but in the spring and fall the 

 southeast are decidedly warmer than the northwest storms. 

 In the high southeast winds the air is clear and dry, but in 

 the northwest cloudy and moist. 



ON ATMOSPHERIC PRESSURE, WINDS AND RAIN. 



A recent supplementary volume of Dr. Petermann's geo- 

 graphical notes gives us a comprehensive memoir on our 

 present knowledge of the atmospheric circulation by Dr. A. 

 Wojeikof, which is accompanied with highly interesting and 

 valuable charts ; the last of the charts gives us a new view of 

 the distribution of rain over the earth, in that it distinguishes 

 between the areas of summer and winter rains, besides giv- 

 ing us the results of the most recent investigations as to the 

 general distribution of the rain-belts of the earth. In gen- 

 eral, Dr. Wojeikof finds that between the poles and 40 of 

 latitude the rainfall is liable to occur at all seasons of the 

 vear, the variations bein^ seasonal in their nature. Thus 

 Siberia and British America receive most of their rains in the 

 summer time; Great Britain, Norway, France, and Portugal 

 receive their rains in the fall. Between these polar regions 

 and the rainless zone of the trade-winds Wojeikof introduces 

 belts of sub -tropical rains, which are, he thinks, essentially 

 oceanic, while the polar rain-belts are essentially continental. 

 In considering the distribution of rain in Siberia, he states a 

 law which, verified by independent observations, is a remark- 

 able confirmation of a theoretical deduction due to Mr. Ferrell. 

 According to Dr. Wojeikof, the atmospheric pressure in win- 

 ter in the higher latitudes is lower over those seas that have 

 no connected ice-fields. According to Mr. Ferrell, the press- 

 ure in the polar regions of the earth is lower in proportion 

 as we diminish the frictional and other resistances offered 

 by the earth to the movement of the air. If, therefore, the 

 resistance offered by fields of ice is sensibly greater than 



