C80 FEDERAL REPORTER. �monopoly over his patented machine, process or combination, and exact such damages as he may be able to show he has suffered from an infringer, he cannot claim any portion of what has been realized as profits in any sense owing or due to him, for the reason that the infringer could just as well have obtained such product, or resuit, without his aid, or the beneôt of his work or ideas." �The rule stated in Mowry v. Whitney was applied by the master to the facts as they appeared in tho case. But he found, after comparison of the patented invention with other devices in use before the invention was made, and ever since in use, — devices open to the public, and free to be used by anybody, — that the defendants had reoeived no gains, profita or advantages by reason of their infringement of the com- plainants' letters patent, and that no such gains, profits or advantages had accrued to them by reason thereof. In thia finding I concur, The evidence certainly established that a 'acomotive with plain forward driving-wheels, — that is, with its forward driving-wheels without flanges, — and with a rigid truck, is in ail respects quite as convenient and economical as is a locomotive with such a truck as the patent describes. There is no gain, profit or advantage in the use of one over the use of the other. The former was in common use when the complainants' patent was granted. It was free to be nsed by the defendants. But the complainants argue that because it was not employed by the defendants when they began to use the combination of the swinging truck with a locomotive, the comparison of advantages should be made ' with an engine having flanged forward driving-wheels and a rigid truck. �I do not assent to this view. The combination protected by the patent is not that of a swinging truck, with a particu- lar kind of engine, such as one having flanged forward driv- ing-wheels. It is a combination of such a truck with any locomotive for railroad" uses. It is the advantage of such a combination to which the patentee is entitled. Certainly, if the defendants had never used any locomotive when they began to employ the complainants' invention, they would, ����
