The question proposed by the defendants was rightly excluded, because it sought not only to add to, but to alter, the written contract by paroi evidence.
As to the description of the contract, there was a variance between the declaration and the proof; but, as the merits of the case appear to have been fully tried, that variance may and should be allowed to be cured after verdict, by an amendment *395of the declaration, the plaintiff taking no costs since the trial. Cleaves v. Lord, 3 Gray, 66. Stone v. White, 8 Gray, 589. Peck v. Waters, 104 Mass. 345.
Upon such amendment, exceptions overruled.