National Geographic : 1926 Jul
THE WORLD'S GREAT WATERFALLS Photograph by Dr. Henry E. Crampton AN OBSCURE AND ISOLATED WONDER OF THE WORLD: KAIETEUR, BRITISH GUIANA The smooth, but rapid, Potaro River, 400 feet wide, "flows quietly to the brink and turns quietly downward," breaking into soft white mist during its fall and reaching the bottom in a chaos of seething clouds. The water tumbles perpendicularly for the first 741 feet, then slopes as a cataract to a still reach below. The entire drop of 80o feet would make almost five Niagaras. When the day wanes, swallows return to the chasm for their night's rest in the cavern behind the falls. incredible velocity in every direction. They mount high in air in spray, and, condensing, descend again and are caught once more in the rising current of wind and water. They rush wildly from each end of the falls canyon, where the abyss is shallowest, toward the middle, both deep and narrow currents seeking escape from the cramping, imprisoning walls of the opposing precipices of basalt. The two sections meet and find this vent about three-fourths of the distance from the western to the eastern end of the chasm, where the raging waters force themselves through another deep crack in the earth's surface even narrower than the falls canyon itself. Down this narrow opening, at right angles to the falls chasm, the reunited waters of the Zambezi rush as rapids with tremendous power, and almost immedi ately dash full front against another preci pice of basalt, and are thrown back on themselves in furious, boiling whirlpool. Thus diverted from its course, the rag ing torrent shoots off almost at right an gles through another narrow gorge ap proximately paralleling the falls chasm and nearly reversing its direction of flow in that chasm (see page 52). When the river is about on a level on this course with the west end of the falls canyon it doubles back upon itself at an acute angle, and when almost on a level with the east end of the falls chasm it re peats this zigzag process, with the result that the Zambezi's course through the falls canyon and the three immediately succeeding gorges lays out a great M, cut into the earth's crust 400 feet deep, plus the depth of the Zambezi's channel in the canyon. A FALLEN. DEGENERATE, WORTHLESS ZAMBEZI Its fall not only thus alters the Zam bezi's physical appearance, but transforms it from a benefactor bestowing blessings into a worthless, wandering tramp.