The main question in this case is whether the plaintiff really suffered any damage by reason of the defendant’s failure seasonably to return the burners and parts of burners which it had borrowed, and the answer to this question depended largely upon the use which the plaintiff would have been able to make of these articles if they had been duly returned to him. If they were covered by a patent so as to be practically unavailable for sale in his hands, he could have suffered no damage by reason of the action of the defendant in withholding them, save the actual value of the material which entered into their composition. For this reason it seems to me that it was clearly erroneous for the court to hold, as it did during the cross-examination of the plaintiff, that it would not permit the defendant to prove what parts of the lamp were covered by a patent belonging to the Belgian Lamp Company or controlled by that corporation. The error was repeated during the direct examination of the secretary and manager of the defendant. It is sought to sustain the exclusion of this exldence on the ground that the pleadings presented no issue as to the parts of the lamp which were or were not patented, and, furthermore, that the record does not disclose the character of the proof which was offered to establish the existence of the patent, and does not show that the letters patent themselves were produced in court. The complaint alleges, and the answer admits, that the lamp burners in controversy were patented articles. This allegation and admission evidently applied to each burner considered as a whole, but had no reference to the component parts. As to such parts it was not necessary that there should be any averment in the pleadings. The question whether any particular part was patented or not was important solely as bearing upon the measure of damages, and the evidence was admissible in that view, even though nothing was said on the subject in the pleadings. As to the nonproduction of the letters patent, the objection to the proposed proof was not based on that ground; and, even if it had been, I think that it was competent to prove, by the cross-*399examination of the plaintiff, the fact, if it were a fact, that he knew the articles to be patented. I am unable, therefore, to agree with the learned presiding justice that no error was committed in excluding the evidence which the defendant sought to introduce for the purpose of showing precisely what parts of the Belgian lamp were patented, and to show that the Belgian Lamp Company was the patentee thereof. On the contrary, I think it was an error which requires a reversal of the judgment. All concur, except GOODRICH, P. J., dissenting.