The decree from which this appeal is taken, so far as it restrained the action of the Registration Commission, expired by limitation on May 21, 1918. The injunction *239is no longer in force, and the question involved is merely academic. It follows, that the reversal of the decree would have no effect whatever upon the rights of any person. It is not the province of an appellate court to consider moot questions or abstract propositions, and to enter judgments or decrees to which effect cannot be given. The question has been very carefully considered in a number of cases without any difference of opinion as to the duty of the court under facts as presented on this appeal. See Com. v. Cairns, 48 Pa. Superior Ct. 265; Faust v. Cairns, 242 Pa. 15, and other cases cited therein.

The appeal is dismissed, the costs to be paid by the appellant.