PL. 18. HOUSE-BOAT WITH OVERHEAD LAUNCHING APPARATUS, 1896 [◊]

The condition of No. 5, which made the first successful flight, is given in the data sheet for May 6, 1896, and its general form at this time may be seen in the photograph of May 11, Plate [27A]. Although the changes described above, as well as the modifications in the boilers and burners of both aerodromes had undoubtedly effected a great improvement in every detail of the machines, the disappointments experienced in the preceding years prevented any great feeling of confidence that the trials which were now to be made would be entirely successful. On May 4, however, the two mechanics, Mr. Reed and Mr. Maltby, were sent down to Quantico with Aerodromes Nos. 5 and 6, and Mr. Langley, accompanied by Dr. Graham Bell, who had been invited to witness the tests, followed on the afternoon of the 5th. On May 6 the wind was so very high all the morning that a test was found impracticable. During the forenoon, however, the wind gradually died down, and by 1 p. m. was blowing from six to ten miles an hour [p107] from the northeast. At 1.10 p. m. Aerodrome No. 6 was launched, but the guy-wire uniting the wings having apparently caught on one of the fixed wooden strips which held the wings down, the left wing was broken before the aerodrome was really launched, and the result was that the machine slowly settled down in the water by the boat, breaking the propellers and slightly injuring the Pénaud tail.

After removing No. 6 from the water, No. 5 was placed on the launching car and immediately prepared for a test. At 3.05 p. m. it was launched at a steam pressure of 150 pounds and started directly ahead into the gentle breeze which was then blowing. The height of the launching track above the water was about twenty feet. Immediately after leaving the launching track, the aerodrome slowly descended three or four feet, but immediately began to rise, its midrod pointing upward at an increasing angle until it made about ten degrees with the horizon and then remained remarkably constant at this angle through the flight. Shortly after leaving the launching track the aerodrome began to circle to the right and moved around with great steadiness, traversing a spiral path, as shown in the diagram (Plate [19]). From an inspection of the diagram it will be noticed that the aerodrome made two complete turns and started on the third one. During the first two turns the machine was constantly and steadily ascending, and at the end of the second turn it had reached a height variously estimated by the different observers at from 70 to 100 feet. When at this height, and after the lapse of one minute and twenty seconds, the propellers were seen to be moving perceptibly slower and the machine began to descend slowly, at the same time moving forward and changing the angle of inclination of the midrod until the bow pointed slightly downward. It finally touched the water to the south of the house-boat at the position shown, the time the machine was in the air having been one minute and thirty seconds from the moment of launching. The distance actually traversed, as estimated by plotting its curved path on the coast-survey chart and then measuring this path, was approximately 3300 feet, which is the mean of three independent estimates. This estimate of the distance was checked by noting the number of revolutions of the propellers as recorded by the revolution counter, which was set in motion at the moment the machine was launched. On the assumption that the slip of the propellers was not greater than fifty per cent, the 1166 revolutions as shown by the counter would indicate a distance travelled of 2430 feet. As it was felt very certain that the slip of the propellers could not have amounted to as much as fifty per cent, it seemed a conservative estimate to place the length of flight at 3000 feet, which would mean a rate of travel of between 20 and 25 miles an hour. The circular path traversed by the aerodrome was accounted for by the fact that the guy-wires on one of the wings had not been tightened up properly, thus causing a difference in the lifting effect of the two sides. [p108]

The aerodrome was immediately recovered from the water and preparations made for a second test, the machine being launched again at 5.10 p. m. at a steam pressure of 160 pounds. The conditions were the same as at the first trial, except that the wind had changed from north to south and was perhaps of less velocity than before. The path traversed by the aerodrome in this second trial was almost a duplicate of the previous one, except that on account of the change in the direction of the wind the machine was launched in the opposite direction. In tightening up the guy-wires, which had not been properly adjusted in the previous test, they were probably tightened somewhat too much, since in this second test the aerodrome circled towards the left, whereas in the first flight it had circled towards the right. The aerodrome made three complete turns, rising to a height of approximately sixty feet with its midrod inclined to the horizon at a slightly greater angle than before. The propellers again ceased turning while the machine was high in the air and it glided forward and downward and finally settled on the water after having been in the air one minute and thirty-one seconds. The distance travelled was estimated as before, by plotting the path on the coast-survey chart, and was found to be 2300 feet.

During these flights several photographs were secured of the machine while it was actually in the air, some of the pictures being taken by Dr. Bell and others by Mr. F. E. Fowle. The clearest of these are shown in Plates [20], [21], and [22].

Just what these flights meant to Mr. Langley can be readily understood. They meant success! For the first time in the history of the world a device produced by man had actually flown through the air, and had preserved its equilibrium without the aid of a guiding human intelligence. Not only had this device flown, but it had been given a second trial and had again flown and had demonstrated that the result obtained in the first test was no mere accident.

Shortly after returning to Washington, Mr. Langley left for Europe, but before doing so he gave instructions to the workmen to remedy the small weaknesses and defects which had been found in Aerodrome No. 6, and to have both aerodromes ready for trial before his return in the fall.

PL. 19. PATH OF AERODROME FLIGHTS, MAY 6 AND NOVEMBER 28, 1896, NEAR QUANTICO, VA., ON THE POTOMAC RIVER [◊] [lgr]