HAR VARD LA W RE VIE W,
works acts are without use in this discussion. Those towns took per formam doni}
The law of running water originated in natural right. If A owns a section of a brook he owns it as such, and ought not to dam it back upon its up-stream neighbor ; nor ought the up-stream neighbor to withhold it from A. Such duty and right grow out of motion, continued, definite, perceptible movement of that part of the realty we call water. When a drop of water enters a definite watercourse, it is practically, and fairly, and legally regarded as destined to reach A, with its benefits of user, power, etc., and the law of running waters arose. No such course of thought, no such desired legal adjustment of correlating rights, call for such law in respect of waters that do not move. Till the water-drop has reached the natural guide which is to compel it to the plaintiff's wheel, it is free. He has no title in it, whether it be in the air, in a bog, or surface water on a hill-side. The great Dismal Swamp is an enormous sponge on top of the ground. The surplus of rain-drops which the sponge cannot hold, seep and percolate about till eventually enough of them cooperate to form a channel, and then a watercourse begins.
Many legal rights have their limitations in practical rules ifor action, and the limit of the right of a riparian on a watercourse is not to the mountain-top, whence in theory the drop starts, but at the point where it becomes practically and substantially con- demned, and in channel guidance to the miller's wheel. On the surface slopes of some mighty glen, swale, or mountain-side, the drop has not yet reached or become a part of the miller's title, for it is not yet a watercourse drop, — it is a surface-drop which any land-owner may exhaust or divert at will. When the drop is stag- nant in some marsh or swamp which leaks out into a brook, it still has not reached the miller's title, for the marsh-owner can drain his marsh or swamp elsewhere.
Thus far we find settled law, and show how serious are the limita- tions of this configuration title alleged to extend from mill to mountain. There is another intervenor as to the character and effect of which it is not ours to decide. That is the still-water lake. Shall the rule of practical sense, above set forth, govern this case, and say it is not a watercourse, or shall the miller at Niagara be
^ Waluppa Co. v. Fall River, 134 Mass. 267; Smith v, Rochester.