608 FEDERAL REPORTER. �tery plan to use on the Hartford & New Haven Bailroad in April, 1873, was the reduction to practice in the form of operative mechanism, as distinguished from modela, and was che embodimeut of the idea in a practical and useful form, as distinguished from experiments, which the law requires. The mechanism to be used was of a peculiar character. It must be used upon and by the aid of a railroad, moving trains of cars as a part of the machinery. It is not to be expected that the inventor could induce the owners of a rail- road to expend money on an extensive scale in a uew enter- prise, neither could he be reasonably expected to place expen- sive structures upon miles of railroad track. It can only be reasonably required that the entire system should be sub- jected to practical, daily, and continuous use upon a railroad by whatever trains pass upon the track. Hall reduced the invention to practice prior to Pope's application, and while, so far as Pope was concerned, the new plan rested in theory. �The plaintiffs rely upon the qualification of the rule that he is the first inventor who has urst actually perfected the invention ; the qualification being that if the one first to con- ceive of the invention was at the time using reasonable dili- gence in adapting and perfecting the same, he is recognized as the first inventor, although the second to concoive may have been the first to reduce to practice. It is also true that the determination of the f act of diligence is not to be reached by comparison of the diligence of the two inventors. If Pope was reasonably diligent in perfecting his idea, it does not matter that Hall was exceedingly diligent and made more rapid advances. �The plaintiffs' position is that Pope had mentally worked out his invention by the first week of November, 1872; that Hall had reached the same resuit in the latter part of December, 1872; that Pope applied for his patent on May 15, 1873, and that there was no laches in this respect. AU this is true; and if, meanwhile, he had been engaged in efforts to perfect his invention, his right to the patent could not be assailed on the ground that another was the first inventor. �It was an important step in this invention to originate the ��� �
