The New Student's Reference Work/Waterfall
Wa′terfall or Cat′aract, a break in the slope of the bed of a river so abrupt that the water falls from the higher to the lower level. They usually occur in mountainous regions, where the streams flow from the mountain sides into valleys. The channel of the river must be rocky to form a fall, as the quantity of water would otherwise soon wear out a side channel. Some of the finest waterfalls are Orco Falls at Monte Rosa, 2,400 feet; Staubbach Falls in Switzerland, 1,000 feet; Zambezi Falls in Africa, 360 feet; Niagara Falls, 163 feet; and among the most wonderful in the world for their great width and the enormous volume of water which pours over them are the Falls of the Yosemite in California, 2,526 feet, the highest in the world.