(after stating the facts)'. This case is here on a writ of error issued upon a petition imputing three several errors in the trial below. The first one assigned was the denial by the court below of defendants’ motion to strike out plaintiffs’ evidence because of variance. The second error assigned was in giving instruction Ho. 1 (recited in bill of exceptions Ho. 2), wherein the court charged the jury that if they believed from the evidence that the defendants below had not made known to plaintiffs, when contracting with them, the restricting provisions contained in defendants’ contract with the railroad company, and that plaintiffs had not otherwise had notice of these provisions, the plaintiffs would he entitled to recover actual damages resulting from enforcing the restrictions. Defendants assign as their objection to this instruction that the court, in giving it, virtually instructed the jury that the questions whether or not the plaintiffs below had accepted and acquiesced in the restrictions, and whether or not the plaintiffs had approved of the final canceling of the contract with the railroad company, could not affect the damages claimed by the plaintiffs. The third error assigned was the court’s allowing to go to the jury the testimony of Bookkeeper Glenn, stating what a plaintiff below had said to him, not in the presence of defendant, as the reason for directing him to change an entry in his hooks.

As to the objection of variance, it nowhere appears, either in the record or in the briefs of counsel, whether or not the contract which is the subject of this litigation was oral or in writing. The *236inference is strong that it was merely oral, however improbable such a- fact may seem. It is also to be observed that plaintiffs in error nowhere, either in their pleadings or brief, give a distinctive statement of the points of difference which they claim to exist between the plaintiffs’ declaration and proofs. The differences relied on are left to the conjecture of the appellate court. As to the alleged variance, and what it consisted in, the facts seem to be as follows: (1) The plaintiffs below declared upon their own contract with the defendants; their theory being that it was not amenable to the provisions of defendants’ contract with the railroad company, authorizing a restriction of monthly work and'a termination of all work, at the will of the company, and that it allowed them full pay on extra work. (2) They introduced evidence to prove their ignorance when they made their own contract of the restrictive and terminative provisions of the previous contract, and of the contention as to the extra work. (3) The defendants below, per contra, introduced evidence to prove these provisions, and that the plaintiffs were aware of their existence at the time they contracted, and acquiesced in and consented to them when they were enforced during the progress of work under the contract. They also produced evidence as to the extra work. We do not think such a state of facts constitutes a variance. The plaintiffs declared, in their special counts, on those provisions of their own contract on which they claimed the damages they sustained from not being allowed to do the full amount of work contemplated by the contract, for which they had made expensive preparations. They were not bound to set out provisions of another contract, to which they were not parties, not necessary to making out their own case. They did state enough to make a case, independently of those provisions. They alleged that the defendants were cognizant of the expensive preparations which they were making for executing the work in the time required, and yet gave them no warning against making these heavy expenditures for that purpose. This itself might, in the opinion of a jury, have entitled them to recover the damages resulting for the restriction and final stoppage of the work, and justified the court below in refusing to strike out the evidence. But, be this as it may, if the defendants below gave evidence to set up at the trial provisions of another contract, tending to defeat, in the opinion of a jury, the plaintiffs’ claim for damages, such evidence did not establish a variance between declaration and proofs. Take a case for illustration. A plaintiff declares upon one or more provisions of a contract. The defendant, in reply, proves additional provisions, which the plaintiff denies. This does not constitute a variance. The establishment of the additional provisions may defeat the plaintiff’s action, in the opinion of a jury. It may convict the plaintiff of false clamor. But this is a matter of weight of evidence, is a matter for the jury, and is not a matter for which a court may dismiss the suit for variance between allegata and probata. In the case at bar the plaintiffs did not declare, even upon their own contract, in ipsissimis verbis. They did not recite its language. And the defendants did not prove a dif*237fevent contract, expressed in different language,, importing different; meaning. There was no idea ding on either side precise enough in language to establish a technical or real variance. The constituents of a variance must be more distinct and tangible, and less vague and indefinite, than any differences appearing between the declaration and proofs in the case at bar. We think, therefore, that the objection of variance must be overruled.

The second assignment of error seems to us untenable. The plaintiffs deny their knowledge of the existence of the restricting provisions of the contract of defendants below with the railroad company, when they made their own contract with defendants. Instruction No. 1, which is complained of, relates especially to the time when the latter contract was made. It is therefore difficult to conceive how a person who has no knowledge of an alleged provision in a contract to which he is not a party can be deemed to have acquiesced in and approved of it. The inquiry directed by the instruction necessarily embraced the I wo questions claimed to have been suppressed. The objection assigned to instruction No. 1 is that it withdrew from the jury the question whether or not plaintiffs acquiesced in and approved the provisions of the contract witli the railroad company. If plaintiffs did not know of, they could not have approved them. But the objection is untenable whether the alleged acquiescence and approval by the plaintiffs were at the time when they made their contract, or afterwards. By the negligence of the manager a plaintiff is injured by machinery so seriously that, to save his life, one of his legs must be amputated, and he acquiesces, and consents to the operation. This acquiescence and consent do not; affect his right to damages resulting from the injuries received, even from the amputation itself, in which he acquiesced. If the plaintiffs below were ignorant of the restricting and terminating provisions of the contract with the raiload company when they made their own, and, not being forewarned of their existence, went on to make expensive preparations for executing the work, before they obtained knowledge of them, they were entitled to recover the damages resulting, whether they afterwards submitted to these provisions or not. What they subsequently approved of or acquiesced ’in, either positively or impliedly, did not affect in any way their right to recover. They may have done many things to reduce their losses to a minimum without prejudice to their right to damages. They did do much. But, whether successful or not in this direction, they were entitled to the actual damages sustained, whatever they may have done to reduce their loss. The court below properly left this matter to the jury, contenting it self with charging that plaintiffs were entitled to recover only actual losses.

The third assignment of error is that the court below allowed Bookkeeper Glenn to give in evidence what one of the plaintiffs told him,—not in the presence of either of the defendants,—as the reason for directing him to change one of the entries he had made in his books. This testimony was given by Glenn in explanation of an entry in books which were themselves in evidence before the *238jury. Witness was asked why this entry was made. He answered, stating his,reason for making it. This he could not do fully, except by stating' what one of the plaintiffs had said to him. It is settled law that when books of account are introduced collaterally, and become evidence in a cause, the reason why this and that entry is made in them can be explained by parol testimony, and such evidence is valid whenever and to the extent’ that it is necessary to the development of the whole truth of the matter. In the case at bar it was not only competent for the bookkeeper to state what he did, but it would have been error if the court had excluded the statement. His statement went only to explaining the making of the entry. It did not go to establishing the truth of the plaintiffs’ contention in respect to the propriety of the entry. The objection of plaintiffs in error to this testimony is therefore overruled.

A further ground of error set out, in one of the bills of exceptions, though not assigned in the petition for the writ, relates to the $500 which was paid by plaintiffs below for immediate possession of the building at Camp Simpson. Defendants below object to the ruling of the court below in allowing this item to go before the jury. Their reason for the objection is that the item was not recoverable under the common counts of the declaration, and that there was no special count claiming this sum of money. This payment to Simpson was necessary to obtaining prompt possession of the principal building at Camp Simpson. As such it was a necessary expenditure in preparing for the performance of the contract. Failure on the part of defendants below tb give possession without this preliminary expenditure by plaintiffs was a breach of contract on their part, and an implied promise of the defendants arose to repay this necessary preliminary expenditure of the plaintiffs, and the item was recoverable in one of the common counts in assumpsit. In two of the bills of particulars filed with the declaration this item was included, and there was no surprise put upon the defendants below in respect to the claim. We think the contention of the defendants below in respect to this $500 is untenable, and it is accordingly overruled. On the whole case, we see no error in the rulings of the court below, and we affirm the judgment there rendered