Plaintiff in its exceptions claims that the chancellor did not properly dispose of his contention that he holds one half of the party wall by adverse possession. Plaintiff and its predecessors in title have been in exclusive possession of the building for over 21 years during which defendant made no use of it and claims that, as a result, the half of the party wall on defendant’s property is plain*760tiff’s by adverse possession. He cites Baxter v. Girard Trust Co., 288 Pa. 256 (1927), a case which involves the question of adverse possession by the encroachment of a building. However, in our opinion, the line of cases covering adverse possession by a wall built upon another’s land does not govern the case before us.
Here the wall was already built on the ground by a common predecessor in title of the parties. Thereafter, the owner of the land divided it by mortgaging part of it by an instrument which divided the building in such a way that one half of the wall went to defendant’s predecessors in title and the other half to plaintiff’s, making the wall a party wall, as this court held in an earlier adjudication.
From the time of the division, plaintiff and its predecessors have done nothing which could be called an adverse taking of possession, since admittedly the use of the windows for light and air is not sufficient for this purpose.
The exceptions are dismissed and the decree nisi is, therefore, made final.