THE WEATHER 



43 



storm visible as a conical or funnel-shaped cloud which is 

 whirling rapidly. 



The path of a tornado is never wide and may not be more 

 than 100 or 200 feet in width. Within this path the destruc- 

 tion is often so complete that all buildings, fences, trees, etc. 

 are leveled to the earth or carried long distances. 



The velocity of the wind within the central whirl is very 

 great, but it has not been possible to measure it. From the 

 character of the results which are produced, it is estimated that 



FIG. 30. Results of a tornado 



These photographs were taken in the path of the tornado which is shown in 

 figure 29. Note the twisted tree and wrecked house 



the wind velocity may be as high as 500 miles per hour. The 

 storm at Mount Morris, Illinois, on May 18, 1898, of which 

 pictures are shown, 'carried off heavy objects (such as stoves), 

 destroyed buildings to the foundation (fig. 30), drove light 

 sticks through or into boards and posts, plucked the feathers 

 from living chickens, and did many other peculiar things. 



Fortunately such storms cover such a small area and occur 

 so rarely that the chance of any one place being visited by one 

 of them is not great. Tornadoes sometimes occur at sea and 

 are then known as waterspouts. 



