After argument and due consideration had, we find no sufficient ground to warrant our disturbing what we have already decided. As appears by the letter of counsel dated April 30, 1927, the defendants, in advance of the hearing by this court, knew that the infringing dampers were bought by the plaintiff. With that knowledge the case was proceeded in and submitted to our determination on the merits of the patent and infringement thereof by the sale of the dampers bought by the plaintiff. Having thus chanced the decision of the ease, the defendant will not now he heard to question a jurisdiction which it has participated in and invited exercise thereof.

Accordingly the petition is dismissed.