The decision was made at October term 1847.

The course of argument relied on in the defence is founded upon certain general principles of law regulating the rights of the various owners of mill sites, or lands through which a watercourse passes, that is capable of being converted to a beneficial use for a mill. Thus it is said that the defendant, when he became the owner, in 1839, of the lower privilege, had a right, by virtue of the conveyance to him, to act, with respect to the owners above, in reference to the state of things actually existing ; and that if he permitted them to continue and uninterruptedly to use the water, to the extent of the existing appropriation, he violated no right as to the upper privilege. This doctrine of the respective rights of adjacent owners of lands through which a watercourse passes, has been recently very fully stated by the chief justice, in the case of Cary v. Daniels, 8 Met. 466, and might, under other circumstances, well maintain a defence in favor of the lower privilege. But the right of the plaintiff is something more than the general right acquired by force of a conveyance of land with a mill privilege. In such case, the purchaser of the upper mill privilege would purchase subject to the actual appropriation below; and if there were no reservation, in terms, by the vendor, he would retain the privilege as actually appropriated and used. The plaintiff here relies upon the particular grant from the original proprietor. Both parties claim under David Stearns, as the original proprietor of their privileges. While Stearns owned the entire privilege, it was competent for him to make stipulations with the purchaser of the upper privilege, creating rights in that privilege, and imposing servitudes upon the lower, that would be binding upon the subsequent purchasers of the lower privilege. Such rights seem to have been granted by the deed of Stearns to Nathan Parkhurst, dated August 24th 1803, in these words: *520“ The grantor hereby grants a privilege to the grantee to dig a ditch from the south end of the new dug way, large and deep enough to convey all the water into the river, without overflowing the meadow, where it will do the grantor’s land the least damage.” Having this right, it is no answer to the plaintiff’s cause of action to say that the injury from the defendant’s flowing back would not be sustained, if the plaintiff forbore to deepen his ditch. This privilege was conveyed by the deed of Stearns, and the grantee was to enjoy the undisturbed use of the water privilege, aided by the ditch dug deep enough to carry all the water.

It is then contended that the practical construction of the deed, given by the parties for so long a period prior to 1839, ought to bind them. Where the language of a deed is dubious, and, from its terms, the mind is left in doubt as to the real intention of the parties, the rule of giving effect to the practical construction, arising from the conduct of the parties, is an important one, and has often been applied. But we do not see any ground for its application here. /

Nor do we perceive any available defence arising from non user, or from the fact that the defendant’s dam was erected in 1839, with the knowledge of the plaintiff, and without objection then interposed by him. The plaintiff might well rely upon his legal rights, under the circumstances of the present case, and seek his remedy in an action for damages, if the defendant’s dam proved, in its practical operation, injurious to the full exercise of the privileges secured to him by his deed from ■ Stearns.

The ruling of the judge at the trial was correct, and the plaintiff is entitled to judgment.