§7. A right of way sometimes arises by _prescription_; which is the right or title to a thing derived from long use and enjoyment. Such is the right which, by common law, a man acquires to land which has been peaceably held by himself, or by himself and preceding owners, for twenty years. Although the first occupancy was obtained without grant, the long free use of the land is, in law, equivalent to a grant, and implies a valid title. In some states, shorter periods have been fixed by statute in which a right by prescription may be obtained. In Pennsylvania, and Ohio, the period is fixed at twenty-one years. §8. The owners of land adjoining highways, have a right to the soil to the centre of the road: the public have only a right of passage while the road is continued. The owners of the soil may maintain a suit against any person who encroaches upon the road, or digs up the soil, or cuts down trees growing on the side of the road. They may carry water in pipes under it, and have every use of it that does not interfere with the rights of the public. §9. Every proprietor of lands adjoining a stream, has naturally an equal right to the use of the water that flows in the stream adjacent to his lands, "as it was wont to run." Each may use the water while it runs upon his own land; but he can not unreasonably detain it, or give it another direction; and he must return it to its ordinary channel when it leaves his estate. He can not, by dams or any obstruction, cause the water injuriously to overflow the grounds of the neighbor above him, nor so use or apply it as materially to injure his neighbor below him. §10. But this right to the use of waters, as an easement to the land, may be acquired and lost, or enlarged and abridged, by prescription. A man may diminish the quantity of the water, or corrupt its quality, by the exercise of certain trades; and by such use of the water for a sufficient length of time, he is in law _presumed_ to have acquired it by grant: and this presumption is the foundation of his right by prescription. The time of such use and enjoyment of water necessary to establish such right is twenty years, except in states in which a different period is fixed by statute. (§7.) §11. It is a general and established doctrine, that an exclusive and uninterrupted enjoyment of water, or of light, or of any other easement, in any particular way, for twenty years, or for any other period which in any particular state is the established period of limitation, is a sufficient enjoyment to raise a presumption of title as against the right of any other person. The enjoyment is deemed to have been uninterrupted, whether it has been continued from ancestor to heir, and from seller to buyer; or whether the use has been enjoyed during the entire period by one person.