1. Defendants insist that the motion in arrest should have been sustained on the ground that the petition failed to state any cause of action. Their contention is, that it was essential to the petition that it contain an allegation to the effect that the plaintiff or his assignor had performed all the conditions of the contract imposed on Warren. The rule that requires an allegation of that kind in an action on a contract applies where the contract requires something to be done by the plaintiff as a condition precedent to his demanding performance of the contract on the part of the defendant. Basye v. Ambrose, 32 Mo. 484; Pier *365v. Heinrichoffen, 52 Mo. 333; City of St. Louis v. Cruikshank, 16 Mo. App. 195. But the rule has no application to suits on contracts, when there are no precedent conditions to be performed by plaintiff to entitle him to demand performance by the defendant, nor when the right to demand performance on plaintiff’s part must be preceded by a performance of a part or the whole of the contract by the defendant. By reading the building contract into the bond, as should be done, to ascertain the full scope and purpose of the bond, it will be seen that the only obligation resting on plaintiff was to pay the installments of the contract price for the construction of the building, as provided in article 20 of the contract. This obligation was not a certain and absolute one to pay. The maturity of the payments are made to depend upon performance of the contract by Dollman and the procurement by him of the architect’s certificate of such performance. Roy v. Boteler, 10 Mo. App. l. c. 222. The burden, therefore, to show that plaintiff or Warren had violated the contract in this respect was on the defendants to show that Dollman had procured the certificate; that he had performed the work under the contract which entitled him to payment. By their answer the defendants set out the stipulation in the contract in respect to payments and averred breaches thereof on the part of Warren. They thereby assumed, and rightfully assumed, the burden of proving those breaches, and that plaintiff had' not performed his part of the contract.
2. It is insisted that the court erred in finding there was no unreasonable delay in paying the first and second certificates of the architect. There is not a word of evidence that defendants or either of them were in the least prejudiced by the few days’ delay in making these payments, nothing to show that they suffered any loss or were put to any expense or trouble on account of the delay and we think the court’s finding on this issue was eminently just.
*3663. The finding of the court that the demurrage of $10 per day for delay in completing the building within the contract time was liquidated damages, is assigned as error. The only evidence of the rental value of the property came from Warren, who placed it at $300 per month. On this evidence the stipulated damages were reasonable and just and there was no evidence to the contrary which would authorize a court to undo' the agreement of the parties that $10 a day should be regarded as liquidated damages.
4. Defendants by separate instructions moved the court to declare the law to be that if Warren detained $589.73 of the contract price, or the sum of $580 for' demurrage on account of delay, or the sum of $9.73 over and above the demurrage claimed, he could not recover, all of which instructions the court refused to give. This ruling is assigned as error.
The evidence is all one way that there was over fifty-eight days ’ delay in the completion of the building. On this state of facts, Warren had a right under the contract to keep back the demurrage. In doing so he kept what was his own, what belonged to him under the contract and we do not understand why the plaintiff should be defeated in this action for the reason that Warren kept his own moneys in his own pocket. In respect to the $9.73 over and above the demurrage that •was confessedly due on the contract, Warren offered to pay it on May 18, 1899, before this suit was begun, but defendants for some reason declined to accept it. They are in no position to charge Warren with a default in respect to the payment of this trifling sum.
5. In respect to the amended reply, it suffices to say that the amendment was entirely useless and unnecessary. The petition, answer and reply raised every issue upon which any evidence was heard and on which the court made a finding.
6. Some shadowy objections were made to two questions asked the witness Smith on cross-examination *367that were overruled by the court. His answers to these questions did not elicit the evidence probably expected. They were not prejudicial to the defendants, did no harm and furnish no ground for complaint.
We discover no prejudicial error in the record. The judgment is manifestly for the right party and is affirmed.
Reyburn and Goode, JJ., concur.