It occasionally happens, though rarely, that around the hollow or valley where it is proposed to form the piece of water, the ground rises in such irregular form, and is so undulating, receding, and projecting in various parts, that when the water is dammed up by the head below, the natural outline formed by the banks already existing, is sufficiently varied to produce a pleasing effect without much further preparatory labor. This, when it occurs, is exceedingly fortunate; but the examples are so unfrequent, that we must here make our suggestions upon a different supposition.
When, therefore, it is found that the form of the intended lake would not be such as is desirable, it must be made so by digging. In order to do this with any exactness the improver should take his stand at that part of the ground where the dam or head is to be formed, and raising his levelling instrument to the exact height to which the intended lake will rise, sweep round with his eye upon the surrounding sides of the valley, and indicate by placing marks there, the precise line to which the water will reach. This can easily be done throughout the whole circumference by a few changes of position.
