LOOOMOTiyB BAFBTT TBUOK CO. V. V. E. 00. 679 �S. S. Hollingsworth a,nà Charles F. BlaJce, for complaînants. �Chapman Biddle, for respondents. �Steong, J. After a careful examination of the evidence submitted to the master, including both the testimony and the exhibits, I have corne to the conclusion that none of the exceptions filed to his report, by the complainants or by the defendants, ought to be sustained. The report is an intel- ligent and discriminating deduction from the evidence, and the conclusions -which the master bas reached are strongly fortified by his reasoning. I can add little to what he has Baid beyond an expression of my concurrence. �In the endeavor to ascertain the profits, if any, which the defendants derived from the use of the patented invention, both parties agreed during the argument that the rule stated in Mowry v. Whitney, 14 Wall. 620, and repeated in subse- quent cases, is to be foUowed. That rule is that the measure of profits, as distinguished from damages, for which an intringer is responsible, is the aggregate of gains or savings which he has made from the use of the patented invention, above what he could bave made, in doing the same work, from the use of any other device or process existing at the time, capable of accomplishing the same pùrpose, or attain- ing the same resuit, and free, or open, to public use. �This rule is founded upon the soundest reason. It is only that which was previously not known — or, in other words, it is only the addition to human knowledge and convenience which a patentee has made — that he canbe said to own. The patent laws give him an exclusive right to that addition, and to the advantages resulting from it, and to nothing more. Undoubtedly, it may be a benefit to the community to have two modes of doing certain work, instead of one, both equally economical and convenient, accomplishing the same result, and each still patentable; but, as was well remarked by the master: "Unless a patentee can show such an absolute ad- vantage in the use of his patent over results which could be reached by other processes in common and unrestricted use, there bas been nothing really gained, no advance made by his invention. In such a case, though he may maintain a ����
