OCR Text |
Show TORNADOES DIFFER FROM CYCLONES Tornadoes are destructive, ro tary storms of small extent, occasioned occa-sioned by a vertical disturbance of the atmosphere. They are tremendous tre-mendous whirlwinds, with terrific power although, as we understand them, the collapse of structures In their path is due to the creation of a vacuum in which interior pressure pres-sure of buildings causes them to explode. The area of a tornado is much smaller than a cyclone, although the latter also involves a circular motion. The cyclone covers a-vast area, sometimes as much as 500 miles and often without extreme violence. The true tornado bounces along the earth, its twisting funnel fun-nel giving visible evidence of its approach. |