The first trial occurred on September 7, 1903, in the middle of the Potomac River at Widewater, Va. The aëroplane was placed on the same catapult, above the boat, that had previously started the models on their smooth and rapid maneuvers. The pilot took his seat, and started the 50-horse-power engine which ran the propellers without appreciable vibration. Tugs and launches were placed along the course where they might be of service. Photographers, on the water and along shore, were ready to furnish important pictorial records of the experiment. The aëroplane was released and sped along the track attaining sufficient headway for normal flight; but at the end of the rails it was jerked violently down at the front, and plunged headlong into the river, sinking beneath the waves. Buoyed up by its floats, it quickly rose to the surface, with its intrepid pilot uninjured, and with little damage to the structure. As revealed by an examination of the catapult and photographs, the guy post that strengthened the front pair of wings had caught in the launching ways, and bent so much that those wings lost all support. The aëroplane, therefore, had not been set free in the air, but had been wrenched and jerked downward. Thus the launching proved nothing of the propulsive or sailing powers of the machine. Those who understand the principles of aviation can judge the merit of Langley’s “aërodrome”[43] from its mechanical description. As shown in Plate XVIII, it was a tandem monoplane driven by twin screws amidships. The pilot seated in the little boat could control the poise and course by several devices; he could shift his weight longitudinally 4.5 feet, laterally 2.5 feet; he could elevate and depress the rear double rudder, which when untouched ensured steady longitudinal poise, on the principle introduced by Penaud; he could steer to right and left by turning about its vertical axis, the wind-vane rudder shown below and rearward of the boat. The lines of lift, propeller thrust and forward resistance passed through the centroid, or near it, thus providing for projectile and gravitational stability. In this feature Langley’s “aërodrome” far surpassed those of his immediate predecessors, whose machines, by reason of their low centroid, possessed the stability of a pendulum, rather than that of a dart, or swallow. These various devices combined should give the craft better control in free flight than that possessed by any of the models, which had flown successfully many times in moderate weather.