Opinion by

The verdict of the jury established the fact that the defendant had entered upon the plaintiffs’ land and had excavated a ditch in which it laid an intake pipe. Its liability was *174thereby fixed. Two questions are raised on the pending .appeal, to wit: What is the measure of damages on the facts established, and was the plaintiffs’ claim assignable? The. defendant is a corporation organized under the act of, 1874. It became desirable in the judgment of its managers to lay a pipe from the Allegheny river to a well constructed for the purpose of receiving water through the pipe. In carrying out this project, it entered on a lot owned by the plaintiffs and dug a ditch from twenty-four to thirty-two feet in depth in which it laid a vitrified tile pipe having a diameter of about thirty inches. This pipe was replaced in about three years by an iron pipe laid substantially on the same line. Before the work of laying the first pipe was completed the plaintiffs sold the lot to R. L. Brown, and. at a later date assigned to him their right of action growing out of the entry by the defendant. The court instructed the jury that the true measure of damages was the difference in value of the lot before arid after the defendant dug the ditch and laid the pipe, and of this instruction the defendant complains. Its allegation, at the trial was that the entry on the defendant’s lot was unintentional, that its purpose was to lay the line in an' alley adjoining the lot and that no part of its line was on the plaintiffs’ premises, and that if by mistake the-excavation was made on the lot the injury was a common law trespass, damage for which was only recoverable, to the time of trial. The defendant’s contention is that as it did not designedly occupy the property it cannot be presumed to have done so under its right of eminent domain, and that therefore the measure of damages stated by the court was inapplicable. It cannot be doubted, however, that the defendant’s structure was permanent iri- its nature and a material part of its plant. It formed a conduit through which water was taken for the supply of the borough of Kittanning. The plairitiffs were justifiable therefore in considering the pipe á permanent and continuing servitude on their land, rind it may well be doubted whether after having permitted the defendant to continue the work without instituting proceedings. to stop it they were' not estopped from depriving the company of the easement. The rule for the ascertainment of damages laid down by the court is not applied exclusively to *175the cases where a corporation is invested with the right to take private property for public use. It has been applied in cases of injury to real estate in actions between individuals: Williams v. Fulmer, 151 Pa. 405. The plaintiffs having elected to proceed for the entire damage in one action, a single recovery can be had which is final between the parties : Hankey v. Philadelphia Company, 5 Pa. Superior Ct. 148; Standard Plate Glass Co. v. Butler Water Co., 5 Pa. Superior Ct. 563; Thompson v. Traction Co. 181 Pa. 131.

It is not disputed that the right of action, if any existed was in the plaintiffs, as the title was in them at the time of the entry and comemncement of the work. This right was personal and could pass by assignment: McFadden v. Johnson, 72 Pa. 335. The use plaintiff does not claim by virtue of the conveyance to him of the lot but under the assignment by the plaintiffs of their claim for compensation for the light of way appropriated. The charge of the learned trial judge was full and clear and gave to the jury a correct statement of the law pertinent to the issue tried. It is unnecessary to consider the assignments of error in detail.

The judgment is affirmed.