The instructions were in conformity to the decided cases and in all respects sufficiently favorable to the *430plaintiff. As to his right to recover on the first count, the agreement was express that the work should be done to the satisfaction' of the county commissioners. The plaintiff was bound to show such acceptance in order to maintain an action on the written contract to recover the agreed price. McCarren v. McNulty, 7 Gray, 139. As to a recovery on the second count, the elements necessary to establish a claim against the defendants and the measure by which the damages were to be assessed were correctly stated by the court. Hayward v. Leonard, 7 Pick. 181. Smith v. Lowell, 8 Pick. 181. Snow v. Ware, 13 Met. 42. Exceptions overruled.