This is a bill for the specific performance of a written agreement to convey land in Chelsea. The agreement was executed by Merriam & Son, purporting to act as agents for the defendant, and the issue submitted to the jury was, whether *185Merriam & Son were the duly authorized agents of the defendant to sell the real estate for the price therein named. An assessor of the city of Chelsea, called by the respondent, was permitted to testify, the complainant objecting, that said land had doubled in value from May 1, 1871, to May 1, 1872. We cannot see that this evidence had any bearing upon the issue on trial. The fact that the land had risen in value had no tendency to prove that the defendant did not authorize Merriam & Son to sell it at the price named in the agreement. As we cannot be sure that this evidence may not have operated to the prejudice of the plaintiff, a new trial must be granted.

Exceptions sustained.