In patent law, either a trial of an uncompleted mechanical structure to ascertain what changes or additions may be necessary to make it accomplish the design of the projector, or a trial of a complet-ed machine to test or illustrate its practical efficiency. In the former case, the inventor’s efforts, being incomplete, if they are then abandoned, will have no effect upon the right of a subsequent inventor; but if the experi-ment proves the capacity of the machine to effect what its inventor proposed, the law assigns to him the merit of having produced a complete invention. Northwestern Fire Ex-tinguisher Co. v. Philadelphia Fire Extinguisher Co., 10 Phila. 227, 18 Fed. Cns. 394
Source: Black’s Law Dictionary 2nd Ed (1910)
