after making the foregoing statement, delivered the opinion of the court, as follows:

The following questions raised by the assignments of error in the case will be considered and passed upon in their order as stated below.

1. Did special plea No. 4 put the set-off claimed by defendants in issue under section 3298 of Code of Va. (the statute of set-off in Virginia), or under section 3299 of the Code of Va. (the statute of recoupment in Virginia) ?

This plea states, with respect to the set-off claimed, that “the said defendants are willing and hereby offer, in pursuance of the statute in such case made and provided, to set-off and allow the same against the said sum of money supposed to be due and payable by the said defendants as demanded in the notice in this suit?”

The plea sets out in totidem verbis the stipulations in writing subject to which all the orders for goods were given, which were given by defendants, for the year 1913. These stipulations were parts of the plea and showed on the face of it that each order given by defendants for 1913 stood alone and formed the basis of a separate and distinct contract with plaintiffs. That these contracts for 1913, as to each order giving exclusive right to sell the goods covered by the order in certain specified territory, ended wheri *63all the 'goods obtained by each respective order were sold. Therefore the ensuing allegations in the plea to the effect that the contract between plaintiffs and defendants existing in the summer of 1915, which was then broken by plaintiffs, was “upon the same basis and conditions as are set out” in said stipulations, alleged facts from which the conclusion necessarily - followed that the contract, out of the breach of which arose the set-off claimed, was a separate and distinct contract from that or those under which the indebtedness sued for by plaintiffs arose.

We are therefore of opinion that the special plea under consideration put in issue the set-off claimed by defendants under section 3298 aforesaid.

2. Did special plea No. 4 describe the set-off claimed by defendants so “as to give the plaintiffs notice of its nature” as required by section 3298 aforesaid?

Such plea alleged that in “the summer of 1915 without notice to the defendants and without cause, it (the plaintiffs) sold a large amount of goods, it had promised and agreed to sell exclusively to defendants, to other parties, to-wit, to E. F. Carpenter and others, contrary to the terms of said contract with defendants. And the said defendants further say that having made and entered into said contracts with plaintiffs, they devoted much time and labor to selling the machinery mentioned in said contract and in advertising same and had .agreed to sell and deliver a large amount of said machinery to customers, and had secured from their customers the promise to buy said machinery from defendants and the profits to defendants from the machinery sold as aforesaid by them to their customers would have amounted to the sum of at least one. thousand dollars. But the said defendants further say that the plaintiffs disregarded its said contract with defendants, sold its said machinery to other parties than defendants in the territory mentioned in said contract, and refused to sell to defendants, so that the defendants were unable to deliver the *64machinery sold as aforesaid to their customers, and to their customers who had agreed to buy said machinery from said defendants, so that defendants were caused by the plaintiffs to lose all the profits that they would have made had the plaintiffs complied with its said contract.”

These allegations clearly describe the set-off as consisting of loss of profits and set forth how and from what cause the loss of profits occurred. It is not perceived how it could have described the nature of the set-off more clearly. It might have gone more into particulars as to the several items of loss of profits, such as giving the names of the customers referred to, on loss of sales to whom the loss of profits alleged occurred, but this would have added nothing to the description' of the nature of the set-off claimed. The plea therefore was sufficient to describe, the nature of the set-off claimed by defendants as required by the statute, section 3298 aforesaid.

The remedy of the plaintiffs to obtain further particulars of the claim was by motion for a bill of particulars under section 3249 of the Code of Virginia, not by objection to the plea. They made no such motion.

3. Was there in the instant case a meeting of the minds of the plaintiffs and defendants in 1915 upon a contract by which the plaintiffs agreed and bound themselves to sell and deliver to the defendants such number of spreaders as defendants might make retail sale of and order of plaintiffs in that year? And Was there any binding obligation on the part of the defendants to take and pay for such spreaders, so as to create a mutuality of obligation in the premises?

It seems clear that the assurances of the plaintiffs to the defendants and the action of defendants upon and in accordance with the condition of such assurances, all as set forth in paragraph (b) of the statement of the evidence above, and the order by the defendants of a carload of *65spreaders, and the further action of defendants in efforts to make retail sales of additional spreaders, evidenced a meeting of the minds of the parties upon a contract such as is covered by the question under consideration. That the order aforesaid created a binding obligation on the part of the defendants to take and pay for the spreaders in question to the extent of the carload of fifteen spreaders there can be no doubt; and it is further true that the refusal of the plaintiffs to ship those and any other spreaders whatsoever, under a well settled rule of law, relieved the defendants of the need to go through the useless performance of in fact giving any further order.

The question 3, under consideration must, therefore, be answered in the affirmative.

4. Was the loss of profit by defendants, on the sales of the twenty-six spreaders, which they in effect made, before the breach by the plaintiffs of the contract referred to in question 3 above, such damage as could be set-off under section 3298 of the Code of Virginia?

This statute, so far as material, is as follows:

“In a suit for any debt, the defendant may on the trial prove and have allowed against such debt, any set-off which is so described in his plea as to give the plaintiff notice of its nature, but not otherwise. * * *”

This statute has been liberally construed in furtherance of its obvious policy which is to prevent a multiplicity .of suits and as far as may conveniently be done to effectuate in one action complete justice between the parties. Allen v. Hart, 18 Gratt. (59 Va.) 722, 729.

It is true that if the amount of the claim of the defendants is so unliquidated that it cannot be ascertained by computation or calculation from definite data supplied by the evidence, and lies in mere opinion, “-as for instance, damages for not using a farm in a workmanlike manner; for not building a house in a good and sufficient manner; *66on a warranty for the sale of a horse; for not skillfully amputating a limb; for carelessly upsetting a stage, by which a bone is broken; for not making repairs to a dwelling house; for unskillfully working raw materials into a fabric; and other cases of like character, where the amount to be settled rests in the discretion, judgment or opinion of the jury,” .such claim cannot be set-off under such statute. Tidewater Quarry Co. v. Scott, 105 Va. 160, 162, 52 S. E. 835,. 115 Am. St. Rep. 864, 8 Ann. Cas. 736, quoting from Butts v. Collins, 13 Wend. (N. Y.) 139. But where the damages are to be assessed upon pecuniary demands and are determinable by computation or calculation from data supplied by the evidence, they' are so far liquidated that they may be set-off under the statute in question. Richardson Co. v. Whiting, 116 Va. 490, 493; 82 S. E. 87; Tidewater Quarry Co. v. Scott, 105 Va., at pp. 162-4. United C. M. Co. v. Brown, 119 Va. 813, 89 S. E. 850.

The case of United C. M. Co. v. Brown, supra, involved in- principle the same question as that now under consideration in the instant case. In that case the appellant had the exclusive right under contract with appellee to supply the demand for certain machines in certain territory, in violation of this right appellee sold a certain number of such machines in- such territory, whereby appellant lost the profit he otherwise would have made on such machines so sold. This court in that case held that “the amount to which appellant thereby became entitled is simply a matter of subtraction from the price at which the machines were sold, the price which appellant was to have paid for them,” and that such lost profit was such a set-off as could and should be allowed under said section 3298.

The question 4 under consideration must therefore be answered in the affirmative.

5. Were defendants entitled to set-off the full amount of $19.50 profit on each spreader, the actual consummation of *67the retail sale which was prevented by the breach of contract of plaintiffs in not selling and delivering same to defendants as agreed?

It is true that such $19.50 was not net profit to the defendants on each of such spreaders. They had to incur the expenditure of the time and of some money in expense in advertising and in canvassing to make such sales. But such expenditure of time and money had been all made before the breach of contract on the part of the plaintiffs was known to defendants. The defendants, therefore, at the time they learned of the breach of contract, had earned the whole $19.50 of profit on each of such spreaders. Hence the defendants were entitled to set-off such full amount of profit on each spreader mentioned in the question we have under consideration.

' It is not a case where a breach of contract occurs before the party thereto claiming damages for its breach has fully performed the contract on his part. In such case indeed the latter party must, as a general rule, as soon as he knows of such breach of contract, minimize his damages by engaging in other employment, if he can obtain it, and not persist in thereafter continuing, in order to aggravate his damages, in a course of conduct which can under the circumstances be of no value to the party who has broken the contract. The authorities cited for plaintiffs of 1 Clark & Skyles on the Law of Agency 830 and 1 Am. & Eng. Enc. of Law (2nd ed.) 1106 on the subject under consideration, have reference to cases such as next above referred to. They have no reference to such a case as that before us, where the profits in question were all completely earned by the defendants before they knew or had any intimation of the breach of contract on the part of the plaintiffs.

It should perhaps be again noted that, as has been above alluded to, any and all expense of delivery to the retail purchasers óf the spreaders in question, had they been shipped *68by plaintiffs, was taken care of in the prices at which they were offered to be sold by defendants, so that said $19.50 on each spreader in question did not include any such expense.

Therefore question 5 under consideration must also be answered in the affirmative.

For the foregoing reasons we find no error in the judgment complained of and it will be affirmed.

Affirmed.