The court are of opinion that the plaintiffs’ own book was rightly rejected. It was of one single large item, and it related to a transaction of which, from the nature of the case, other and better evidence could be given. It is a questionable species of evidence, admitted from necessity only, and is intended for the aid of mechanics and small dealers who keep daily accounts of their transactions. Faxon v. Hollis, 13 Mass. 428. It is a dangerous species of evidence, and not to be ex tended by new precedents. Per Sewall, J. Prince v. Smith, 4 Mass. 457.
*223Upon the other point, considering the limited extent and nature of the business, respecting which it was proposed to bind the defendant by proof of a custom, the instruction was sufficiently favorable to the plaintiffs. The court of common pleas instructed the jury, that if such a usage was proved to exist, and that the defendant knew that such a usage existed; it raised an implied promise to pay the plaintiffs such a commission as they claimed, and would entitle them to recover.
No instruction was given, and none was asked by'the plaintiffs, as to the means of proof of such knowledge. We take the rule to be, as applicable to a case like the present, that if the usage is so general, so uniform, and of such long continuance, that every ship-owner might be presumed to be acquainted with it, then the jury might infer the fact of actual knowledge by the defendant. Stevens v. Reeves, 9 Pick. 198. But such inference of knowledge would be a presumption of fact and not of law, and therefore it would be for the jury, and not the court, to draw it. There is nothing in the case to show that any direction was given, on the subject of knowledge of the usage, inconsistent with the rule above stated, nor to show that the jury were not left at full liberty to infer such knowledge from the nature and extent of the usage.
Some observations were made, and authorities cited, on the question of the reasonableness of a custom for ship-brokers to receive a commission, where they have introduced a person, as a purchaser, to the owner of a vessel wishing to sell, without being employed in the negotiation. As the verdict was for the defendant, it has become unnecessary to express any opinion upon this question. See Dalton v. Irvin, and Broad v. Thomas, 4 Car. & P. 289, 338. Wilkinson v. Martin, 8 Car. & P. 1. Burnett v. Bouch, 9 Car. & P. 620. Read v. Rann, 10 Barn & Cres. 438.
Exceptions overruled.