Intelligence and Miscellaneous Articles. 



157 



where little snow falls in winter, and this small quantity is often 

 blown away by the strong winds, winter crops are scarcely attempted 

 at all. On the northern coasts of the Black Sea, summer wheat and 

 Indian corn are very good ; but winter wheat is a precarious crop, 

 while to the north, in Podolia, it is the principal crop. There the 

 forests afford a protection against the wind, the snow falls more co- 

 piously and cannot be blown away. 



As a bad conductor of heat, the snow isolates the warmer soil 

 from the cold air above ; and there is no doubt that it renders also the 

 winter cold more intense, as the air cannot receive heat from below. 

 In countries where the snow-covering is not permanent, as Western 

 Europe, this influence of snow is well known, and people expect 

 great cold where a layer of snow has fallen and the sky clears. In 

 countries where snow usually lies the whole winter, as Russia and 

 the northern parts of America, this is not generally understood, and 

 in Russia people say it is colder without snow than with it. This 

 feeling is quite natural. The first frosts of autumn are more severely 

 felt because the human body is not accustomed to them, and also 

 because the air is drier than with snow, and a cold dry wind is more 

 severely felt than a cold moist one. 



The great relative humidity of the air is a most important feature 

 of the countries covered with snow in winter. It is as easy to account 

 for it as for the humidity of an island in the middle of the ocean, or 

 of a place situated in an extensive swamp-tract. The wind may come 

 from every side, it has always to pass over a large evaporating sur- 

 face, and absorbs moisture if it was originally dry. In countries 

 where cold strong winds predominate, as in the greater part of North 

 America and Eastern Asia, this will be less the case, as the winds, 

 rapidly passing over the land, have not the time for absorbing much 

 moisture ; and the dryness of the air in the United States is felt by 

 Europeans going there. But in countries situated like Europe and 

 Western Asia, where the cold winds are usually weak, and only the 

 warm southerly winds strong, the air will be always nearly saturated 

 when the soil has a snow covering, as the cold winds in their slow 

 progress have the time for absorbing moisture. This feature of cli- 

 mate is extremely important in the examination of storms. It was 

 one of the chief merits of Espy to have pointed out the importance of 

 vapour in the origin and progress of storms ; and this is now gene- 

 rally admitted. If a storm is signalized and the beginning of its 

 path stated, it is important to know the quantity of vapour dissemi- 

 nated in the countries where it is likely to pass, and the quantity 

 which may be expected to be condensed as rain and snow. Now, 

 the lower the temperature falls, the more uncertain are observations 

 of the psychrometer ; and I am of the opinion that it it not a sure 

 guide below the freezing-point. This stated, it is very important to 

 have some general idea as to the quantity of vapour over the cold 

 spaces of the earth's surface. Now in countries situated like Europe, 

 relative humidity will scarcely fall below 75°-80° so long as the 

 earth is covered with snow, so that the quantity of vapour in the air 

 of these regions may be very nearly known if we know the tempera- 



