Opinion by
Trexler, J.,The plaintiff’s predecessor in title conveyed certain lands, including the premises owned by the defendant and reserved “the right to the tailrace from the gristmill that now passes through said lots, the width at bottom to be and remain twelve feet, with such a slope or inclination of the sides or embankments as will best preserve them. And .they further reserve to themselves, their heirs and assigns the free and undisturbed right to enter on the premises at all times and remove all and *577every obstruction to the easy flow or passage of the water along the same. And the several parties do for themselves, their heirs and assigns covenant and agree to and with the said (grantors) and their assigns that they will never do nor cause to be done any act or thing whereby the said water will or may be obstructed in its passage.”
Many years ago the owners of the fee erected a platform across the mill race and put a one-story frame kitchen thereon. There is some testimony to the effect that the platform was constructed of one-inch boards nailed down, and that there was a small trapdoor left in the platform. This structure was allowed to remain for over twenty-one years. Afterwards, and within the prescriptive period preceding the commencement of this suit, the structure was changed. An additional story was put upon the kitchen and according to the testimony of some it was enlarged. Did this change damage the plaintiff and interfere with his rights? We do not think that the reservation kept for the grantor the mill race and with it the right to the open space up to the sky. The grant of the fee subject to the easement carried with it the right to the grantee to make any use of the servient soil that did not interfere with the easement: Duross v. Singer, 224 Pa. 573. The owner of the servient soil has the right to make use of his property as he chooses, if by so doing, he does not substantially interfere with the easement: Mercantile Library Co. v. Fidelity Trust Co., 235 Pa. 5; Chambersburg Woolen Co. v. Hager, 66 Pa. Superior Ct. 63.
We may assume that the erection of the platform was an invasion of the plaintiff’s rights, but when these rights were gone by twenty-one years’ adverse enjoyment of benefits inconsistent with said rights, the plaintiff could only recover if he showed a new or additional invasion. Although the platform evidently interfered with plaintiff’s approach to the race, it does not appear in the evidence that he ever took up the boards in order to clean the race. If this platform effectually cut off the ap*578proach to the race, then any superstructure put upon it was not an invasion of plaintiff’s rights nor an interference with his reservation.
We think the case should have been submitted to the jury along these lines. The platform heretofore erected having, at least to some extent, deprived the plaintiff of access to the race along the lines of defendant’s property, did the change of the platform or of the superstructure thereon in any substantial degree add to- that deprivation? If part of the platform was removable and it can be shown that plaintiff within the twenty-one years exercised the right to remove it for the purpose of entry into the race to remove obstructions therefrom, and if the new erection on the top of the platform prevented him from doing the same as he had theretofore done, he would be entitled to damages. There was no evidence that the platform, except a portion, was constructed in a temporary manner, in order that it might be readily removed. On the contrary, to afford access to- the race there was a trapdoor put in it which could be opened and closed at will, and this trapdoor still exists. If the former platform restricted and obstructed the plaintiff as much as the present structure, he is not entitled to recover anything in the case. If the remodeled structure in any way caused an additional obstruction to the race, then he should recover. This is substantially what the learned trial judge said in parts of his charge, but he also laid great stress upon the superstructure. We quote from the charge', “There is no substantial dispute, but that for more than twenty-one years prior to the bringing of this suit, this raceway was covered by a construction over the entire extent of its passage through what is now the defendant’s property. However, instead of the superstructure placed on that platform or placed over the raceway instead of its being a very permanent building extending the full width of the raceway and most of its length, according to Dr. Dowlin it was a one-story summer kitchen that extended only a part of *579the distance across the raceway and a substantially less distance along the raceway than does the present two-story structure.” “If he is right then there must have been ten feet of this raceway lying between the eastern side of this structure and the eastern side of this property, covered only by the platform.” Further on, “We think the real matter and the material matter in the case is the superstructure.” The real question was the character of the platform and if the platform, whether substantially built or not, successfully prevented access to the race for twenty-one years on the part of the plaintiff and his predecessors in title, defendant, after that time, had the right to put any structure on the platform, except on such portion if any as was specially designed to afford access to the race. The right of access to the extent of defendant’s interference thereof was gone forever, and as to that there was no right of plaintiff that could be invaded above the platform. Certainly the addition of another' story to the kitchen would under such conditions add no additional obstruction to plaintiff’s approach to the race, neither would the extension of the kitchen across the platform add anything. The third and sixth assignments of error are sustained.
We do not think there was sufficient in the case to raise an estoppel against the plaintiff. Whilst it appears that he had knowledge of the erection of the second building, we find nothing in the case which would indicate that defendant was misled by any act of plaintiff’s predecessor. No estoppel can be inferred from his mere silence.
The judgment is reversed with a venire facias de novo.