The complaint alleges that by the contract the plaintiff "did warrant said cotton gin to be equal in all respects to the best saw gin then in use." The defendants reiterate this averment, and the contract set out in the answer, and accepted by the plaintiff as correct, justifies the statement. The defendants set up a breach of this warranty as a defense to the plaintiff's action, and the referee has found in *Page 265 favor of the defendants upon that issue. This finding is sustained by the General Term, and is obviously supported by evidence. It cannot therefore be reviewed in this court.
The learned counsel for the appellant however insists that the referee erred in receiving the opinions of witnesses upon the point referred to, but we think the evidence was properly admitted, and that the exception thereto must fail. In the first place testimony of the same character had already been given by the plaintiff, and in the next place the fact in issue could only be determined by a comparison of the merits of various machines, with those of one constructed under the plaintiff's invention. There was an inquiry of the plaintiff's principal witness, concerning the "condition of the cotton as to cleanliness as it came from different machines," and he says "from the plaintiff's gin it was cleaner and whiter," and from comparison he speaks of the greater production of one machine over the other, the quality of its work, economy of operation, and facility of repair, in each instance giving an opinion. The plaintiff speaking as a witness, and testifying in his own behalf, goes a little farther. Referring to the contract he says, at the time of making it, "I was acquainted with the various saw gins then in use" * * * and being asked by his counsel, "How did the saw gins compare with the American Needle Cotton Gin and Condenser" (the one in question) "at the time of the execution of the contract * * * in their operation and working," answered, "They were very inferior to the American Needle Cotton Gin and Condenser at the time of the execution of the contract." Similar testimony was given by Viall and True, both witnesses for the plaintiff. The example thus set was followed by the other side, and the plaintiff's objection is therefore unavailing. But we think the evidence was competent. The defendants' witnesses called to express an opinion were not merely experts, nor were they called upon to give an opinion upon a theoretical state of facts, but were asked for their judgment upon matters within their personal knowledge, happening under their own observation, and concerning which they *Page 266 were competent from education and experience to form and declare an opinion.
The general rule requires a witness to testify to facts, and not conclusions. Yet to this rule there are exceptions, and one is here presented. The parties by their contract required that the cotton gin covered by the patent "should be equal in all respects to the best saw gin then in use." To determine this question, special knowledge was necessary, and this could be best acquired by experience in the use of that and other machines made for a like purpose. Indeed it is doubtful whether any other person could answer it. The invention or a machine made under it could be described, and its operation, as it affected the quantity and quality of the substance with which it was fed, stated to the referee; and all this was done, but it was also proper to take the opinion of competent persons, as to its practical working, and its comparative value.
The inquiry related to a matter which was not the subject of general knowledge, but depended on facts which from their nature it would be difficult if not impossible to place before the referee, and the statement embodied in the opinion given in evidence, was itself a fact derived from peculiar knowledge and skill in the use of the various machines referred to. It was the result of professional knowledge, and practical experience (Emerson v. Lowell Gas Light Co., 6 Allen, 146), and the question raised by the warranty could hardly be answered except by the direct opinion of those, who possessing this superior knowledge and experience had seen the machines in operation, or knew the merits of machines constructed under the plaintiff's patent, and others then in use. Upon this ground therefore, as well as the one first stated, I think the evidence objected to was properly received. Nor do I discover that the referee erred in any other ruling.
The judgment should therefore be affirmed.
All concur.
Judgment affirmed. *Page 267