By the custom which has obtained among miners in the Pacific States and Territories, where mining for the precious metals is had on the public lands of the United States, the first appropriator of mines, whether in placers, veins, or lodes, or of waters in the streams on such lands for mining purposes, is held to have a better right than others to work the mines or use the waters. The first appropriator who subjects the property to use, or takes the necessary steps for that purpose, is regarded, except as against the government, as the source of title in all controversies relating to the property. As respects the use of water for mining purposes, the doctrines of the common law declaratory of the rights of riparian owners were, at an early day, after the discovery of gold, found to be inapplicable or applicable only in a very limited extent to the necessities of miners, and inadequate to their protection. By the common law the riparian owner on a stream not navigable, takes the land to the centre of the stream, and such owner has the right to the use of the water flowing over the land as an incident to his estate. And as all such owners on the same stream have an equality of right to the use of the water, as it naturally flows, in quality, and without diminution in quantity, except so far as such diminution may be created by a reasonable use of the water for certain domestic, agricultural, or manufacturing purposes, there could not be, according to that law, any such diversion or use of the water by one owner as would work material detriment to any other owner below him. Nor could the water by one owner be so retarded in its flow as to be thrown back to the injury of another owner above him. 'It is wholly immaterial,' says Mr. Justice Story, in Tyler v. Wilkinson, 'whether the party be a proprietor above or below in the course of the river; the right being common to all the proprietors on the river, no one has a right to diminish the quantity which will, according to the natural current, flow to the proprietor below, or to throw it back upon a proprietor above. This is the necessary result of the perfect equality of right among all the proprietors of that which is common to all.' 'Every proprietor of lands on the banks of a river,' says Kent, 'has naturally an equal right to the use of the water which flows in the stream adjacent to his lands, as it was wont to run (currere solebat) without diminution or alteration. No proprietor has a right to use the water to the prejudice of other proprietors above or below him, unless he has a prior right to divert it, or a title to some exclusive enjoyment. He has no property in the water itself, but a simple usufruct while it passes along. Aqua currit et debet currere ut currere solebat. Though he may use the water while it runs over his land as an incident to the land, he cannot unreasonably detain it or give it another direction, and he must return it to its ordinary channel when it leaves his estate. Without the consent of the adjoining proprietors he cannot divert or diminish the quantity of the water which would otherwise descend to the proprietors below, nor throw the water back upon the proprietors above without a grant or an uninterrupted enjoyment of twenty years, which is evidence of it. This is the clear and settled doctrine on the subject, and all the difficulty which arises consists in the application.'