The agreement of Hugh Jelly and Thomas Scott, executed January 20, 1807, was to “leave four feet and a half (1%) of each of their respective parts or lot of ground so as to form an alley of nine feet wide between them from Fifth Street to Virgin Alley,” and the following is a part of it: “Which said alley shall be called Kings, and for the convenience of each other and the Borough of Pittsburgh and the citizens thereof forever. To be kept free and open from all obstruction whatsoever. And for the true performance of the agreement herein-before mentioned and agreed to, both parties bind themselves each unto' the other by these presents in the penal sum of two hundred dollars to be paid to the party per-formant by the party delinquent.” The dedication was never accepted by the Borough or City of Pittsburgh, but the alley was opened and used down to the time this bill was filed by Jelly’s and Scott’s successors in title. The defendants, such successors, owning property on each side of the alley, undertook to connect two of their buildings by a brick and tile structure over it, at a height of 17% feet above its surface, when this bill was filed by Frank H. Mellon, another successor in title, *212owning property adjoining the alley. In the proceeding instituted by him, Thompson McClintock and other successors in title and adjoining owners, intervened as plaintiffs. From the decree awarding the injunction prayed for thereds this appeal.

It was contended in the court below that, in view of the penalty of two hundred dollars fixed in the agreement, the complainants were confined to an action at law for any damages they might sustain. The conclusion of the learned chancellor was that the said clause was intended simply as additional security for the performance of the covenants of the agreement, and not merely as something to be substituted for the performance. His 14th finding of fact is as follows: “The erection of the proposed building by the defendants over Kings alley, as shown in said Exhibit ‘E,’ attached to the answer to the bill of Frank H. Mellon, will materially interfere with the light, air and prospect now enjoyed by the McClintock property from Kings alley, and likewise by that portion of lot No. 6 in schedule ‘B’ of the partition of the estate of David Greer, deceased, which is embraced in lot No. 403 of the general plan of the Borough of Pittsburgh, abutting on Kings alley.” This was not excepted to below and has not been assigned as error here. On it and the conclusions of law reached by the learned chancellor the decree is affirmed, at the costs of appellants.