The plaintiffs have, in my opinion, shown that the defendant entered into a contract with the plaintiffs by which the plaintiffs would have secured pipes and valves from a building in the course of destruction if the defendant had fully carried out its contract. They have shown, further, part performance of the contract sufficient to take it out of the Statute of Frauds, if that statute ever applied.
While there are, perhaps, technical errors in the case, I think that, were there any sufficient proof of damages, the judgment should be sustained. Certainly, in spite of general criticisms in the appellant’s brief of a nature too frequently found in briefs submitted to us, the record shows that the trial justice carefully and patiently tried the case and ruled courteously and promptly on all objections properly presented ; and such general criticisms should receive neither consideration nor support from this court. I believe that we should point out, as forcibly as possible, to attorneys who come before us that we will carefully consider all criticism of the record presented to us, but we will not consider and strongly object to all criticism of a general nature not borne out by the record.
The only error of importance in the record is in regal'd to the proof of damages, but I think that this error leaves no substantial basis upon which the judgment can stand. The ' evidence of damage must present two features: First, there must be some evidence upon which a reasonable estimate may be formed as to the quantity of material which the plaintiffs would .have secured if the defendant had complied with its contract; second, there must be evidence of the difference between the market price of this material and the cost price under the contract. In other words, the plaintiffs must show what material they would have received and the loss sustained by them in failing to receive it.
Hpon the first point the only, evidence is that given by the plaintiffs and other dealers in building materials, that they *422went into a cellar and saw some pipes exposed there, and from that estimated the whole amount probably in the building. It may be that experts who examine a building in this way can with reasonable precision make such an estimate. Expert testimony is, however, useless and improper unless the court has knowledge of the facts upon which the opinion is based. If these expert witnesses had testified as to what they saw in the cellar, it would 'be possible to find out whether their “ opinion ” had any sufficient basis. In the present case, however, it was apparently mere guess work; in fact, one of the witnesses could not apparently even remember what he saw in the cellar but only the estimate he had made when he went into the cellar. In the recent case of Weibert v. Hanan, 200 N. Y. 328 at 331, the court held: “ It is a general rule in regard to the opinion evidence of experts that the facts upon which the opinion of the witness is founded must be laid before the trial court either by 'assuming them in a hypothetical question or by the testimony of the expert himself if he has observed them.” The .failure to follow this rule vitiates the expert’s opinion evidence and leaves no basis upon which the amount of material may be estimated.
Upon the proof of the difference between the market and the cost price, the evidence admitted was also erroneous. The plaintiffs testified that they had a special market in which they sold material of this kind for a higher price than rules in the general market, arid the trial justice based the damages upon the higher price. The market price which determines the plaintiffs’ loss ‘is the general market price at which they could have bought this material; the special market price at which the plaintiffs cari sell would.determine their loss of profits only, and loss of profits cannot be shown as general damages.
Judgment should be reversed and a new trial granted, with costs to appellant to abide the event.
Giegerich and Pendleton, JJ., concuri.
Judgment reversed and nqw trial ordered, with costs to appellant to abide event.