THE CLIMATE OF THE LAKE REGION.* 



/"CLIMATE is constituted chiefly of temperature, hu- 

 ^-^ inidity and winds. Under average conditions, tem- 

 perature is by far the most important of the three. So 

 far as our bodily organs are concerned, it is chiefly the 

 sensible temperature which is afl'ected by changes in the 

 humidity and movements of the atmosphere. In warm 

 weather an increase of humidity is equivalent to an in- 

 crease of heat; in cold weather it produces the sensible 

 effects of a diminution of heat. The extremes of tempera- 

 ture are, consequently, most felt in humid climates. 



Winds, by promoting evaporation, and a consequent 

 drying of the soil, though they tend primarily to the 

 production of humidity, result speedily in a partial ex- 

 haustion of the sources of moisture, and a consequent 

 aridity of the atmosphere, which diminishes the sensible 

 effects of temperature. Their direct influence upon sensi- 

 ble temperature is far greater. A movement of the 

 atmosphere is always cooling, even though the tempera- 

 ture be nearly that of the blood. This eff'ect is produced 

 largely by the promotion of evaporation from the skin. 

 In cold weather it is due partly to the penetration of our 

 clothing by portions of air impelled through every pore 

 by the pressure of other portions behind them. At all 

 temperatures winds also exert an actual cooling influence 

 by the promotion of evaporation, during which large 



* Based, in part, by permission, on an article contributed to Harper''s Magazine. 



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