LyoN, J.
1. At the close of plaintiff’s testimony the defendants moved for a nonsuit on the ground that the evidence failed to show or tend to show a hiring for any specific time. The motion was denied. Before the motion was made, the plaintiff had testified to a conversation with one of the defendants 'when the contract of hiring was made. On his cross examination he thus detailed that conversation: “I asked him how much he could give. He said, $75 a month. I thought a moment. Says I, ‘All right; I will take $75 a month, but I will' not agree beyond the 1st of January.’ He says, ‘ All right; we will call it $75 a month until the 1st of January, and then we may make a new bargain.’ ” This testimony tended to show a hiring until January 1st, and was sufficient, at least, to send that question to the jury. Moreover, after the motion was denied, additional evidence was given tending to prove the same proposition. The motion for a nonsuit on the ground stated was, therefore, properly denied.
2. On cross examination the following questions were put to the plaintiff: “ You represented to Mr. Yam, Yalhenburgh (one of the defendants) that you were a book-keeper and competent to keep books, did you not? What business were you engaged in after you left the employ of the defendants ? ” Counsel for defendants further offered to show by the witness (the plaintiff) that he refused to obey the proper and lawful orders of the defendants in the matter of keeping the books and in the conduct of his business, and that there was no other reason for his discharge. The court sustained objections to the questions and offer on the ground that the same were not proper cross examination. The first of the above questions was quite immaterial. When the plaintiff accepted employment to perform services for the defendants, *255requiring skill on his part, he impliedly undertook that he possessed such skill, and it is of no importance whether he represented that he possessed it or said nothing about it. Had the question been allowed, it would have been of no consequence whether it was answered in the affirmative or negative. Neither the obligations of the plaintiff nor the rights of the defendants would have been affected by the answer. Hence, if erroneously rejected, it is not an error that will work a reversal of the judgment.
Had the witness not been the plaintiff there can be no doubt that both questions and the offer were properly rejected as not being proper cross examination, for the reason that the witness had not been examined in chief on those subjects. True, he had testified to a conversation with the defendant Van Valhenburgh, and the defendants were entitled to the whole of that conversation; but the first question (besides being immaterial) is general and not directed to that conversation. The other question and the' offer call for purely defensive testimony on subjects concerning which the witness had not testified. The second question related to plaintiff’s employment after he was discharged, and, if material at all, it was so because the answer might have tended to show that the plaintiff earned, or could have earned, more than he admits in the complaint This is matter of defense (Barker v. Ins. Co., 24 Wis., 630) as is also the alleged incompetency of the plaintiff. We do not think the admission in the complaint of the amount earned after his discharge can operate to change the burden of proof on that subject to the plaintiff, or affect the rules governing his cross examination as a witness. Probably the fact that the witness was a party to the action would justify the court in its discretion in allowing a broader range of cross examination than would be allowed were the witness not a party. Knapp v. Schneider, 24 Wis., 70. Rut that is not a right of the adverse party, and ordinarily the rules of cross examina*256tion are tbe same whether the witness be a party or not. Howland v. Jenckcs, 7 Wis., 57. While, therefore, it might not have been error to allow the proposed cross examination, it certainly was not error to disallow it.
3. The plaintiff was allowed, against objection, to read to the jury the original answer. That answer was verified by one of the defendants, and contained an unqualified admission that they employed the plaintiff to serve as their bookkeeper until January 1, 1881. There can be no doubt that the admission in the answer was competent evidence to go to the jury for what it was worth, on the question as to what were the terms of the contract between the parties.
4. The remaining errors assigned are based upon exceptions to the instructions given by the court to the jury. The charge is quite lengthy, and it is impracticable to quote here the passage upon which errors are assigned. A general statement of those portions must suffice. The question as to what were the terms of the contract of hiring was clearly and fairly submitted to the jury. They were instructed that if the contract was for no specific time, or being for a specific time if the defendants reserved the right to discharge the plaintiff when dissatisfied with him, the plaintiff could not recover. But if they-found that the plaintiff was employed to serve until January 1, 1881, and the defendants did not reserve such right, then if the plaintiff was a competent book-keeper and properly performed his duty, the defendants had no right to discharge him when they did, and the plaintiff could recover. In that event the measure of damages was stated tó be the contract wages — that is $75 per month — from June 29, 1880, to January 1, 1881, less the amount the plaintiff might reasonably have earned elsewhere during that time. Thus far the charge states the law correctly, and is not assailed.
The jury were further instructed that, finding the contract of hiring to be as claimed by the plaintiff, it was the duty *257of the plaintiff “ faithfully to perform, his labor, and do it promptly and correctly, and also to be respectful in his communications, written and verbal, with the customers and correspondents of the defendants; ” and if he failed in these respects, or was incompetent to perform his duties properly, the defendants had the right to discharge him, and there could be no recovery in the action. This, also, was undoubtedly a correct statement of the law. The learned circuit judge commented to some extent on the subject of the degree of competency required of the plaintiff, but we find nothing in his remarks which could mislead the jury or prejudice the defendants. It was left to them to find from the evidence whether the plaintiff was or was not a competent book-keeper, and whether he did ■ or did not perform his duty with reasonable skill and fidelity. This is sufficient.
5. The learned circuit judge stated to the jury some of the recognized tests for determining the credibility of witnesses, and the relative weight to be given to conflicting testimony. He then told the jury that if they were unable to reconcile apparently conflicting testimony, they must determine what portion of it was true and what false by the application of the tests given, and all other tests within their slcill and power. It is claimed that the last portion of the instruction gave the jury too much latitude in determining the credibility of witnesses. We think otherwise. The jury are the sole judges in that matter. All the court can do is to aid them by laying down the leading rules by which credibility should be tested when the testimony is in conflict. This was done here, and presumably the jury gave due weight to the instructions and faithfully applied the rules enunciated by the court. But if, in the exercise of sound, intelligent judgment, the jury were conscious of other tests of credibility not -enunciated by the court, it was manifestly their duty to apply the same otherwise the jury would not be the exclusive judges *258of the credibility of witnesses and the truth or falsity of conflicting testimony.
6. The defendants failed to produce on the trial any of their account-books which the plaintiff had kept while in their service. The jury were instructed that they were at liberty to consider such failure as tending to show that the plaintiff was competent, and kept such books in a proper manner; and, further, that although the plaintiff might have compelled the production of the books, he was not bound to do so, and his failure to compel their production in court raised no presumption against him. We discover no error in these instructions. This disposes of all the material errors assigned for a reversal of the judgment. We conclude that none of them are well assigned.
By the Court. — The judgment of the circuit court is affirmed.