Note 129 — Chapter IV

"The Horse-shoe Cataract on the British side is the largest of the Falls. The curvatures have been geometrically computed at 700 yards, and its altitude, taken with a plumb-line from the surface of the Table Rock, 149 feet; the American fall, narrowed by Goat Island, does not exceed 375 yards in curvilinear length (the whole irregular semicircle is nearly three quarters of a mile), its perpendicular height being 162 feet, or 13 feet higher than the top of the Great Fall, adding 57 feet for the fall. The rapids thus give only a total of 219 feet, which is less than many other falls; but their magnificence consists in the volume of the water precipitated over them, which has been computed at 2400 millions of tons per day, 102 millions per hour! A calculation made at Queenston, below the Falls, is as follows: The river is here half a mile broad; it averages 25 feet deep; current three miles an hour; in one hour it will discharge a current of water three miles long, half a mile wide, and twenty-five feet deep, containing 1,111,400,000 cubic feet, being 18,524,000 cubic feet, or 113,510,000 gallons of water each minute."—Montgomery Martin's History of Canada.