Larger water-falls and cascades cannot usually be made without some regular head or breastwork, to oppose more firmly the force of the current. Such heads may be formed of stout plank and well prepared clay;* or, which is greatly preferable, of good masonry laid in water cement. After a head is thus formed it must be concealed entirely from the eye by covering it both upon the top and sides with natural rocks and stones of various sizes, so ingeniously disposed, as to appear fully to account for, or be the cause of the water-fall. (* It is found that strong loam or any tenacious earth well prepared by puddling or beating in water is equally impervious to water as clay; and may therefore be used for lining the sides or dams of bodies of made water when such materials are required.)
