In patent law , either a trial of an uncompleted mechanical structureto ascertain what changes or additions may be necessary to make it accomplish the designof the projector, or a trial of a completed machine to test or illustrate its practicalefficiency. In the former case, the inventor’s efforts, being incomplete, if they are thenabandoned, will have no effect upon the right of a subsequent inventor; but if theexperiment proves the capacity of the machine to effect what its inventor proposed, thelaw assigns to him the merit of having produced a complete invention. NorthwesternFire Extinguisher Co. v. Philadelphia Fire Extinguisher Co., 10 Phila. 227, 18 Fed. Cas.394.