306 



PHYSIOGRAPHY 



A more violent tornado was that at Louisville on the 27th of 

 March, 1890, just before nine o'clock in the evening. Its rate of 

 advance was nearly 40 miles per hour, but its diameter was so 

 slight, about 300 yards, that it took but about three-fourths of a 

 minute for the storm to pass a point. It was accompanied by "a 

 most terrific electric display." Many weak buildings were wrecked, 



Fig. 258. Weather map for the morning of the day (March 27, 1890) of the 

 Louisville tornado. (U. S. Weather Bureau.) 



76 persons were killed and about 200 injured in Louisville alone, 

 and the loss of property was estimated at about $2,500,000. 



Waterspouts. Waterspouts are tornadoes at sea. When the 

 base of the upward spiral movement is down to the surface of the 

 water, sea-water may be drawn up to some slight extent by the 

 ascending current. The lesser atmospheric pressure in the center 

 of the whirl will occasion the rise of the water to some extent at 

 that point, and the upward current of air may catch it and carry 

 it upward. But the larger part of the water in a waterspout is 

 probably cloud, formed by the condensation of the water vapor in 

 the air, and not by the uplift of water from the sea. 



