Pinney, J.
1. The instruction that, “if the greatest weight of evidence tends to establish the fact as claimed by the party upon whom the burden of proof rests, and you are satisfied thereby to a reasonable certainty of the existence of such fact, you should find in favor of such party in respect to such claim, otherwise against him,” is not objectionable as laying down the rule applicable to criminal cases, requiring that the evidence shall be such as to satisfy the jury of the guilt of the defendant beyond reasonable doubt. "When the plaintiff and defendant have *46both put in their evidence, the burden of proving his whole case by a preponderance of evidence in civil cases is on the party who had the burden in the beginning of the trial. Powers v. Russell, 13 Pick. 76; Perley v. Perley, 144 Mass. 104; Phipps v. Mahon, 141 Mass. 471; Willett v. Rich, 142 Mass. 356. If the plaintiff pleads in confession and avoidance, his burden of proof includes none of the allegations of the complaint. Powers v. Silberstein, 108 N. Y. 171. The expression “ reasonable certainty ” is not strictly accurate as a definition of the weight of evidence required, and may mean no more than that quantum of evidence which satisfies or convinces the mind of a reasonable person of the truth of a particular claim or contention. Possibly, however, it may mean more, and so be misleading. "We think it better, in such cases, to stop with stating the usual rule that the party having the burden of proof must establish his case by a preponderance or the greatest weight of evidence. If the instruction is to be regarded as erroneous, the error was clearly prejudicial only to the plaintiffs, upon whom the burden of proof rested in all respects, except in relation to whether the plaintiffs stopped cutting by consent or agreement, and whether they acquiesced in the act of the defendant forbidding their further cutting of timber. The preponderance of evidence in respect to the points upon which the burden of proof was on the defendant was clearly and very decidedly against him, and it is plain that he was not injured by the instruction.
2. The instruction that, “ if a witness had testified wil-fully false in regard to any matter material to the case, the jury had a right, if they saw fit, to reject all of the evidence of such witness not corroborated by some credible evidence produced,” is in accordance with the law as laid down in Mercer v. Wright, 3 Wis. 645, and was correct.
3. The evidence is clear and decisive that the defendant’s agent in charge, on Sunday the 6th of March, 1892, forbade *47the plaintiffs cutting any more timber on the land, and three days afterwards defendant refused to consent to their proceeding to perform the contract, and was guilty of a breach of the contract. He assumed a right to put an end to the contract on the ground that, as he supposed, the logging-season was substantially at an end, and that it had become impossible for the plaintiffs to perform their contract within the stipulated time, then forty days distant; but he misjudged in this respect, for the weather changed and the logging season continued until near the end of March. It was properly submitted to the jury to find whether the plaintiffs were willing and able to perform and complete their contract according to its terms, and the jury found, this issue in their favor. The defendant, in stopping the work, took whatever risk there -was in this respect on himself. It was no defense to the action that the wrongful act of stopping the work occurred on Sunday, for we do not understand that the defendant can escape the consequences of his wrongful act, even though prohibited and made penal by statute. The plaintiffs not only acted on this notice, and quit work, but three days after they asked the defendant’s consent to proceed with their contract, but he reaffirmed his notice by refusing consent. The claim that the plaintiffs informed the defendant that they could not carry out the contract, and that he took them at their word and forbade further cutting of timber, and that plaintiffs consented or acquiesced in the termination of the contract, is negatived by the verdict of the jury, and this is in accordance with the very great preponderance of evidence.
4. The rule of damages given in the charge to the juris in conformity with the law established by several decisions of this court,— that the plaintiffs, having been prevented from fully performing the contract, were entitled to recover the profits which they would have realized by put*48ting in all the logs on the defendant’s land according to the contract; “ in other words, they might recover the difference between the contract price and what it would have cost them to have put in the remainder of the logs.” Salvo v. Duncan, 49 Wis. 151, 155; Wood v. Schettler, 23 Wis. 501; Corbett v. Anderson, 85 Wis. 218, and cases cited. To this rule we adhere. The plaintiffs had made preparations for performing the entire contract by making roads, getting supplies and men, teams, etc., for that purpose, and their interest in the contract had thus been made more valuable. They had an undoubted right to the contract price as damages, less what it would have cost them to have completed the contract. What it had already cost them for the construction of roads for that purpose or otherwise was not material to this question, and evidence offered on this point was properly excluded. The plaintiffs received pay for the 58,000 feet they had already put in; and what it had cost to put in these logs, and what profit the plaintiffs made on them, was thus eliminated from the case, and had no relevancy to the question of damages. And so, also, the exclusion of evidence to show what the plaintiffs made under a second logging contract, made with Carmichael, during the same logging season, after the breach of the contract with' the defendant, offered in reduction of damages; was correct. The contract was not one for personal services, and non constat but that the plaintiffs might have obtained means and resources with which to put in these logs for Carmichael, as well as to have performed their contract with the defendant.
5. The instruction on the subject of the allowance of interest from the date of suit by way of damages was permissive, and not mandatory, and was warranted by adjudicated cases. Hinckley v. Bechwith, 13 Wis. 37; Vaughan v. Howe, 20 Wis. 497; Gammon v. Abrams, 53 Wis. 323; Tucker v. Grover, 60 Wis. 245.
*496. There was no error in the admission of evidence given by one of the plaintiffs that, with the crew they had and provisions and equipment, they could have put in that 1,000,000 feet from the time he stopped them up to the 28th ■of March. This was in the nature of expert evidence, and admissible (Salvo v. Dunoon, 49 Wis. 157); and the testimony of Carney, a lumberman, that it would cost $1.50 per 1,000 to haul this pine, provided everything was as Watterson had testified, comes within the same category; and so as to what it was worth to supply men for putting in logs per 1,000.
7. The questions asked the witness Anderson as to what it cost him the next winter for supplies, and as to what it cost him to put in logs that winter, excepting supplies, were not relevant. The evidence wholly fails to show facts necessary to make such a comparison admissible, and the questions related not to any matter in question, but tended to raise collateral issues which would tend to confuse and complicate the case, instead of elucidating it. The evidence was properly restricted to the cost at the time when the contract required the work to be performed.
There is no ground for contending that the verdict is contrary to the evidence, or that the damages are excessive, and, though other questions were raised, we have considered all that appear to merit discussion. We have not been able to find any material error in the record.
By the Court.— The judgment of the circuit court is affirmed.