The opinion of the court was delivered by

To sustain this defence would be to allow a contract to be changed by one of the parties to it. If the house was finished, and the defendant could not get the $175, there would be some equity in his defence. He is indeed paying for *73what he has not received; but it would be very inconvenient to allow this as a set-off in such an action, for it would throw open a perpetual rent to a perpetual dispute, by an unwritten alteration of its amount, and thus make set-offs to be the cause of- strifes, instead of a way of ending them, and this must be watched against.

And it makes no difference that Mangle’s title was sold on Stiles’s judgment. The law, and not the plaintiff, fixes the effect of a judgment, and makes it a lien only on the defendant’s title; and a sale under it can reach no further, except against ¿secret equities. Stiles had a right to enforce his judgment against this Jot, and the purchaser under it assumes Mangle’s unfulfilled covenants, both as to the rent, and as to the means of securing it by the erection of the house.

Judgment affirmed.