Opinion by
Rice, P. J.,This was an action of assumpsit upon a book account for goods sold and delivered. The pleas were non assumpsit, set-off, payment, etc. The defendant filed an affidavit of defense in which he alleged, that he was the contractor for the plumbing of a certain building; that he ordered from the plaintiff seven legs which were designed to support a number of marble partitions between the water closets in the said building, which purpose was fully explained to the plaintiff, whereupon the plaintiff undertook to manufacture said legs or supports in a manner proper for the purpose aforesaid; that thereupon it became the duty of the plaintiff to so construct them that they should be fit for the purpose for which they were intended, but notwithstanding the plaintiff thoroughly understood the purpose, it did by its servants negligently and carelessly construct certain of them and so that the defendant could in no way detect the fault; that the plaintiff delivered said legs or supports to the defendant, the charge for the same appearing in the copy of the book entries attached to plaintiff’s statement; that while the workmen of the defendant, who are thoroughly skilled and used all due care in the erection of the partitions, were setting them in place, one of the legs or supports, by reason of the negligent construction aforesaid, broke, causing the partition resting upon the same to fall against the remaining partitions, by reason of which the seven marble partitions together with the three marble slabs forming the backs and one marble slab forming the end of said closets were totally destroyed causing the plaintiff a loss of $255.50, so that, instead of the defendant owing the plaintiff the sum of $229.51 as claimed in the plaintiff’s statement, the plaintiff was indebted to the defendant in the sum of $25.99, for which amount he would .ask a certificate at the hands of the jury upon the trial of this *310cause. This was the only defense alleged. On the trial the plaintiff' offered in evidence its statement of claim containing a copy of its book entries, and rested. The defendant then made an offer to prove, in substance, the facts alleged in his affidavit of defense. This was objected to because, to quote the words of the objection, “No notice of special matter has been filed in this case, as required by the rule of court; or, I mean to say it was not served on me, and I presume it was not filed.” In overruling the objection the learned 'trial judge remarked: “ I think this evidence is admissible under the plea of set-off. The rule seems to be that under a plea offset off, if you desire notice, you must take a rule for it.”
Every court is the best judge of its own rules, and will not be reversed for any construction unless it is manifestly erroneous and injurious: Carpet Co. v. Latimer, 165 Pa. 617; Mendenhall v. Mendenhall, 12 Pa. Superior Ct. 290, and cases cited. The trial court being more familiar with its rules and the practice under them than the appellate court can be, a specification assigning error in the violation of one of its rules will not be considered where it is not clearly made to appear that there was such violation: Morrison v. Nevin, 130 Pa. 344. Even if we were to attempt to construe Rule 30, which seems to be the one relied on, we ought to have before us all its sections, before declaring that the section (16) printed in the appellants’ paper book applies to cases where the defendant has pleaded “set-off,” as he may under the act of 1887. We do not say that an affidavit of defense setting forth particularly in what the defence consists obviates the necessity of giving notice of special matter, or of the intended set-off or counterclaim, where the rule of court unequivocally requires such notice to be given: Sullivan v. Johns, 5 Whart. 366; Erwin v. Leibert, 5 W. & S. 103; Finlay v. Stewart, 56 Pa. 183; Xander v. Commonwealth, 102 Pa. 434. It is to be borne in mind, however, that the purpose of such rule is to prevent surprise, and if, as alleged at bar and not denied, the same evidence was admitted on the former trial of the case without objection, it is morally certain that the plaintiff was not surprised by its introduction on the second trial. We are not to be understood as deciding that this was a sufficient reason for disregarding the rule, if there be such a rule; it is nevertheless satisfactory *311to know that if there was technical error it was not injurious. But we overrule the assignment upon the ground that it does not clearly appear that the court violated its own rules in admitting the evidence. The court below having declared what the rule is where there is a plea of set-off we do not feel called upon to go outside the bill of exceptions in search of something to convict the court of error. In view of the declaration of the trial judge he should have been asked to include in the bill of exceptions the precise rule governing the practice. We might have dismissed the assignment for the reason that it is not in strict conformity to our rules: Arnold v. Blabon, 147 Pa. 372.
The defendant was the general contractor for the work described in the affidavit of defense, and employed Jacoby & Company for a lump sum to do part of it, namely, to furnish and set the marble, the defendants to furnish the metal supports therefor. Without fault of Jacoby & Company, as the jury found, one of the supports gave way before the work was completed, in consequence of which the marble slabs fell and were broken. The plaintiffs’ contention is that Jacoby & Company were bound by their contract to replace the slabs and complete the work for the sum originally agreed to be paid. We cannot assent to this proposition. Jacoby & Company had nothing to' do with the selection of the supports. They did not buy them from the defendant. The argument that there was between the defendant and Jacoby & Company the relation of vendor and vendee is ingenious but not convincing. We cannot see that the rule caveat emptor applies. Jacoby & Company could not perform their part of the contract unless the defendant furnished proper supports. Their engagement was to exercise due care and skill in the use of them and to do the work in a skilful and workmanlike manner, and if they discharged that obligation they were not liable as for a failure' to perform, if the support selected and furnished by the other party had a latent defect which rendered performance with that instrumentality impossible. This is not the case of a person undertaking absolutely to construct a particular thing according to plans, and wholly out of materials, furnished by him, or of a failure because of accident or the happening of something unexpected for which neither party was responsible. The falling of the marble slabs *312was not owing to a failure to do the work as agreed, but to a cause over which Jacoby & Company at no time had control, and for which, according to the verdict of the jury, they were not responsible. Nor was it a mere accident. The destruction of the work they had done resulted from the failure of the defendant to perforin his part of the contract with them. In that sense it resulted from a cause for which, as between them, the defendant was responsible. None of the cases cited by the appellant’s counsel rules the precise question presented here; nor do we say that these cases rule it; but they are pertinent: Campbell v. Gates, 10 Pa. 483 ; Swan v. Lytle, 1 Pittsburg Rep. 177; Filbert v. Philadelphia, 181 Pa. 530; Kellogg Bridge Co. v. Hamilton, 110 U. S. 108. We conclude that, when, pursuant to the defendant’s express direction, Jacoby & Company got other marble and put it in the place of that which had fallen and been broken, the defendants’ liability to pay them the reasonable cost of the extra work and materials was complete.
The next inquiry is as to the right of the defendant to set off against the plaintiff’s demand the loss that he sustained by reason of the negligent and defective construction of the supports. Before proceeding to a discussion of this question we remark that this was not an attempt to set off a debt which the defendant owed to Jacoby & Company for which the plaintiff was primarily liable to the latter, but to set off the damages the defendant sustained by reason of the plaintiff’s breach of contract. The fact that the measure of these damages was the cost of repairing the injury does not make the payment of the debt incurred for that purpose a condition precedent to the defendant’s right of recovery. We cannot see that the plaintiff is concerned with that matter. Therefore, the second assignment is overruled.
As to the general proposition that in Pennsylvania a defendant may set off unliquidated damages arising ex contractu from any bargain whenever they are capable of liquidation by any known legal standard, we need only refer to Hunt v. Gilmore, 59 Pa. 450. There was no difficulty in liquidating the defendant’s damages, if under the evidence he was entitled to damages.
-The plaintiff contended on the trial, and contends here, that it was not liable for the. damages sustained by the defendant in consequence of the defective construction of the supports, be*313Cause there was no warranty on its part that they should answer the particular purpose for which they were ordered, even though that particular purpose was made known to it at the time they were ordered. The defendant’s contention is that there was an implied promise or undertaking that the articles would be reasonably fit and proper for the purpose for which the plaintiff undertook to make them. The evidence bearing upon this particular question was not in conflict The plaintiff’s version of the transaction did not differ materially from that of the defendant, which was to the effect that the plaintiff corporation was a manufacturer; that when he ordered the supports or legs he explained to its salesman the purpose for which he desired them, and stated to him the dimensions of the marble slabs to be supported; that the salesman said “ they could do that,” but as he knew nothing about the mechanical part, he would call in the foreman of the manufacturing department; that the defendant made the same explanation to the latter of what was to be supported; that the foreman said “ they made lots of those things,” and drafted it out on a small piece of paper; whereupon the defendant gave them the order to make the legs. So far as appears, the defendant gave no direction as to their construction, excepting as to the thickness of the pipe constituting the “ core,” and we do not understand it to be claimed by either party that this had anything to do with the accident. The question whether or not it happened in consequence of the defective construction of one of the supports was in dispute and was submitted to the jury fairly. The court coifld not have affirmed the plaintiff’s fifth and eighth points without declaring at the same time that there was neither an implied engagement that the thing ordered would be fit for the purpose intended, nor that it would be free from latent defects. We do not think the court would have been justified in taking this position. Without attempting to give all the differently worded statements that have been made of the rule of law applicable to the sale of things to be manufactured, we take that statement chosen by the appellent’s counsel: “ The rule invoked is that, where a manufacturer contracts to supply an article which he manufactures, to be applied to a particular purpose, so that the buyer necessarily trusts to the judgment of the manufacturer, the law implies a promise or undertaking on his part that the article so *314manufactured and sold by him for a specific purpose, and to be used in a particular way, is reasonably fit and proper for the purpose for which he professes to make it, and for which it is known to be required; but it is also the rule, as expressed in the textbooks and sustained by authority, that where a known, described and definite article is ordered of a manufacturer, although it is stated by the purchaser to be required for a particular purpose, still, if the known, described and definite thing be actually supplied, there is no warranty that it shall answer the particular purpose intended by the buyer: ” Seitz v. Brewers’ Refrigerating Machine Co., 141 U. S. 510. In the case cited the contract was to supply a “ No. 2 size refrigerating machine as constructed by the said party of the first part.” The machine so designated was delivered and put in operation. It was held that the only implication in regard to it was that it would perform the work the described machine was made to do, and as it was not pretended that there was any failure in such performance (in this respect differing from the present case), the plaintiff was not permitted to recover. But the court took pains to say that the case was not one of an alleged defect in the process of manufacture (in this respect also differing from the present case), nor of presumptive and justifiable reliance by the buyer on the judgment of the vendor rather than his own, but of a purchase of a specific article manufactured for a particular use, and fit, proper and efficacious for that use, but in respect to the operation of which, in producing a desired result under particular circumstances, the buyer found himself disappointed. So in Jarecki Manufacturing Co. v. Kerr, 165 Pa. 529, the defendant ordered of a dealer a particular kind of pipe known in the trade as “ Pennsylvania tubing,” and the kind of pipe ordered was delivered. It was held that the case came within the second branch of the rule above stated. In Port Carbon Iron Co. v. Groves, 68 Pa. 149, this was said to be the law: “ If a thing be ordered of the manufacturer for a special purpose, and it be-supplied and sold for that purpose, there is an implied warranty that it is fit for that purpose. This principle has been carried very far. It must, however, be limited to cases where a thing is ordered for a special purpose, and not applied to those where a special thing is ordered, although this be intended for a special purpose.” For, as was said in *315the text-book from which the foregoing was taken, if the thing is itself specifically selected and ordered, there the purchaser takes upon himself the risk of its effecting its purpose: 1 Parsons on Contracts, 586, 587.
Accordingly, if the buyer gives an order to a manufacturer or dealer for “ your patent hopper and apparatus to fit up my brewing copper with your smoke-consuming furnace,” (Chanter v. Hopkins, 4 M. & W. 399); or for “ your challenge augur outfit for boring wells,” (Goulds v. Brophy, 42 Minn. 109) ; or for a “No. 2 size refrigerating machine as constructed ” by the manufacturer, (Seitz v. Brewers Co., supra); or for a quantity of “ Pennsylvania tubing,” a well known article of commerce in which he deals, (Jarecki Mf’g Co. v. Kerr, supra); or for a quantity of “your No.1 and No. 2 foundry pig iron ” (Beck v. Sheldon, 48 N. Y. 365), in these and like cases there is no implied engagement on the part of the seller that the specified article shall serve the special purpose for which the buyer obtains it: Bur-dick on Sales, 100. Having bought a specified article under its trade name, he is deemed to have relied on his own judgment. This case is not parallel with any of those cited by the appellant’s counsel. The defendant did not order an article by its trade name, nor a definite existing chattel specifically described or open to his inspection, but a thing to be manufactured that would support the burden that was to be put on it. The plaintiff through its foreman professed its ability to make an article fit for the purpose explained to him. This was the thing that the plaintiff undertook to make. The defendant had a right to trust, and under the evidence the plain inference is that he did trust, to the judgment and skill of the plaintiff. It is not to be presumed that he trusted to his own judgment merely because he did not exact an express warranty. Such an argument impeaches the whole doctrine of implied warranty for there can be no sale of personal property in which the buyer may not, if he chooses, insist on an express warranty against latent defects: Kellogg Bridge Co. v. Hamilton, 110 U. & S. 108. We are of opinion that the case is fairly within the first branch of the rule as stated in Seitz v. Brewers Co. And, if the plaintiff’s engagement was that the things ordered should be reasonably fit and proper for the purpose for which they were to be made, it extended to latent defects which might have been guarded against by the *316exercise of reasonable skill and diligence in the process of manufacture: Kellogg Bridge Co. v. Hamilton, supra, Randall v. Newson, L. R. 2 Q. B. D. 102; Erie City Iron Works v. Barber, 102 Pa. 156 ; s. c., 106 Pa. 125, at pages 140, 144.
The correctness of the plaintiff’s bill was not disputed, and "the jury should have been instructed that if they found that the defendant was entitled to a set-off they should give a certificate in his favor for the amount by which it exceeded the plaintiff’s claim. Instead of doing that they were told to give a certificate for the whole amount of the set-off to which they found him entitled. This was a mistake, but it may be corrected without a retrial of the case. We find no other substantial error. Some of the defendants’ points might have been refused as inapplicable to a case of this kind, but in the view we have taken and expressed as to the nature of the contract and the implied engagement of the plaintiff their affirmance did no harm.
The judgment in favor of the defendant is reduced from $255.50 to $25.99 and as thus modified the judgment is affirmed.