Opinion of the Court

Inventors many decades ago studied the flight of winged animals and sought without success to imitate their motions and bring into being a device that would accomplish, with the aid of man, what flying birds, eagles, vultures, etc., did with natural ease. This record is replete with a large number of exhibits, publications, and patents which antedate Montgomery by years, disclosing the extent of sustained interest in the art, and efforts made to accomplish flying in a heavier-than-air machine.

Montgomery first centered his attention upon the subject in 1883; from this date until 1886 he conducted a number of experiments with some sort of a mechanism designed as a "glider." He does not seem, at this time at least, to have conceived the idea of soaring from the ground and remaining aloft in a device under control. What he was attempting was the construction of a machine that might be released from high altitudes and glide safely to earth under control. From 1886 until 1903 Montgomery turned his attention to other and distinct inventive fields; he contributed nothing to this particular art during this period. In 1903 he renewed his experiments. During that year he came in contact with one Baldwin, a balloonist, who had been making successful glides from a hot-air balloon in a parachute. Baldwin became interested in Montgomery's efforts and the two entered into a contract, whereby Montgomery was to construct his device, and if it proved successful in descending from a balloon with a man on board the two were to engage in public exhibitions and divide the profits. Montgomery and Baldwin disagreed before any actual experimentation with the prospective glider obtained, and Montgomery thereafter entered into a somewhat similar contract with another balloonist. Montgomery had constructed in May, 1904, a large machine to meet the requirements of the Baldwin contract, and in the summer of 1904 carried on some experiments at the ranch of Peter Cox, in California. The exact and detail structure of his machine is not disclosed. The experiments made consisted in elevating the machine to a desired height by suspending it from a wire to which it was attached, stretched between two upright

358-28-c C-VOL. 65-35

Opinion of the Court

poles. At the proper time it was released to ascertain its gliding qualities. Other tests were made by resorting to a steep hill, when men, by means of a rope, pulled it down the incline, Montgomery holding onto the device. Just how many and the exact character of the tests so made is impossible of determination. It is sufficient to observe that they were quite numerous. In March, 1905, Montgomery attached his machine to a hot-air balloon, and having secured the services of an aeronaut by the name of Maloney to make the test the machine with Maloney in the saddle seat was released from the balloon at a high altitude and safely glided to earth. On July 8, 1905, Maloney attempting the same experiment lost his life, the machine failing to function. On April 26, 1905, Montgomery filed his application for the patent in suit. The patent was granted on September 18, 1906.

We have epitomized Montgomery's early efforts, with respect to which a great volume of proof has been adduced, solely because the plaintiffs have sedulously insisted that the facts are sufficient to antedate the effective date of invention to a time which would exclude reference to certain prior art. A careful analysis of the record upon this point is conclusively convincing that the proof signally fails to sustain the contention. Out of fifty-two prior patents and publications cited in the record all but eight bear dates which make them statutory bars, provided they disclose the structure of the patent in suit. The courts have uniformly held that to show anticipation as against issued letters patent some drawing, some model, some positive means of identification must appear. Oral testimony is regarded as insufficient and unreliable for this purpose. Without exception it is to be discarded, for, however free from intentional misrepresentation, it is uniformly tinctured with the interest of the parties in the litigation and necessarily characterized with acute limitations of the possibility of particular and precise descriptions of the device and its comparison with another. Symington Co. v. National Malleable Castings Co., 250 U. S. 383; Deering v. Winona Harvester Works, 155 U. S. 286; The Barbed Wire Patent, 143 U. S. 275; Torrey

Opinion of the Court

v. Hancock, 184 Fed. 61; Emerson & Norris Co. v. Simpson Bros. Corp., 202 Fed. 747.

The flight of April 29, 1905, took place three days after Montgomery's application for a patent was filed, and is available solely as proof on the point of operativeness.

It is impossible from the record to abstract with any degree of accuracy the detail structure of Montgomery's early machines. He preserved no data, kept no record of measurements, and left no reliable information from which a court or one skilled in the art might profit from what he did, or ascertain the means he employed to do it. At best, the evidence is probative on the single point that the patentee did on the dates stated do the things described, and discloses only the happening of the chronicled events. True, Chanute in 1894, in his book Progress in Flying Machines, devotes an article to Montgomery's experiments, in which he outlines in general terms the Montgomery machines, from which one may abstract a conception of general lines of construction; however, it is clear from what was therein said, and the results of the tests described, that it would be hazardous indeed to ascribe to Montgomery a distinct conception at this time of those fundamental principles of aerodynamics, which finally culminated in the invention of the airplanes which it is now claimed infringe the patent in suit. If, however, Chanute's article did disclose the specific features of Montgomery's device, then the article itself stands as a statutory bar to the validity of the patent. Montgomery's articles and addresses printed in the record found publication years after his application for the present patent had been filed and granted, and are purely ex post facto.

There are 46 claims in the Montgomery patent. Infringement is alleged as to claims 4, 9, 12, 16, 17, 18, 28, and 32. The device claimed is manifestly a combination of elements designed to function in certain ways. Fig. 1 of the patent illustrates a side elevation of the patented machine. We reproduce it from the letters patent:

To fly in a heavier-than-air machine, one capable of bearing aloft a man, exacted the creation of a device that would function in a variety of ways. First, it must be capable of soaring from the ground. Second, equilibrium when aloft was indispensable. Third, directional control was equally essential. Fourth, stability must be accomplished, and finally, the means to descend when desired was no less important. Soaring, equilibrium, control, and gliding were concededly indispensable. Noted scientists from an early date discovered the above requisites if a successful flying machine was to materialize. The difficulties encountered

Opinion of the Court

were not so much in the discovery and recognition of the principles involved, although tedious and prolonged, as in the means available to apply them in a practical manner.

The claims of the Montgomery patent which disclose the invention we think may be grouped. First, those which are directed toward the accomplishment of equilibrium and lateral control, dealing especially with a change in wing curvature to accomplish the purpose. This group, we think, comprehends claims 4, 16, and 28. Claim 16 being typical and most comprehensive of the group we quote it at this point:

"A curved aeroplane with means for changing its curvature, and a horizontal tail behind, which means for swinging it vertically."

The second group may be said to be directed to the relative arrangement of the supporting and control surfaces, and would include claims 12, 17, and 18. Claim 17 we regard as typical of this group and therefore quote it:

"In an aeroplane device, plural curved aeroplanes one in advance of another, and a horizontal tail-surface behind the last aeroplane with means for swinging said tail-surface vertically."

The third group is made up of certain claims which, in addition to the foregoing, are predicated upon or limited to a specific type or character of supporting surfaces, defined in the claims as "curved parabolically." curved parabolically." In this group we place claims 9, 12, and 32. Claim 9 we regard as typical and quote it:

"An aeroplane curved parabolically from front to rear, its front portion being rigid, and its rear portion adjustable, with means for adjusting said rear portion relatively to the front portion, to change the surface of the aeroplane."

Originality and novelty ascribed to the first group reside in the alleged fact that the claims disclose a form of construction whereby through a change in the curvature of the wings, integral with the wing surfaces, equilibrium and lateral control of the machine in flight are secured. Wing surfaces on planes enable the airplane to soar; they furnish, through the reaction of air currents, the "lift " and support;