The contract upon which the plaintiffs rely was made by the defendants with the plaintiffs, as a corporation. It is an agreement to pay to the treasurer of the Worcester Medical Institution. The act of incorporation is shown. Acts of incorporation are now deemed public acts. Rev. Sts. c.2, § 3; and printed copies of them published under the authority of the government are admitted as evidence. Rev. Sts. c. 94, § 58. The proof of the act of incorporation, of the action of the plaintiffs under it, and of the contract of the defendants with the plaintiffs as such corporation, was suffi*289nient for the maintenance of the suit by the plaintiffs in their corporate name. Indeed, it seems to be well settled that the defendants, having contracted with the corporation, would be estopped to deny its existence. Narragansett Bank v. Atlantic Silk Company, 3 Met. 282; Congregational Society in Troy v. Perry, 6 N. Hamp. 164; Dutchess Cotton Manufacturing Company v. Davis, 14 Johns. 238.

The question what was meant by the words of the written agreement, “ when the walls shall be completed,” being a question of the construction of the contract, was a question of law for the court. The construction of the presiding judge was correct. What the contract required to be done was a question of law for the court; whether it had been done, a question of fact for the jury.

Exceptions overruled.