After returning in the fall, Mr. Langley again had Aerodromes Nos. 5 and 6 taken down to Quantico for trial, and this time had as his invited guest Mr. Frank G. Carpenter. On November 27 a test was made of Aerodrome No. 6, the general disposition of which at this time may be learned from the description in Chapter X, and the photographs in Plates 29A, 29B. The model was launched at 4.25 p. m. with a steam pressure of 125 pounds. The aerodrome went nearly horizontally against the wind, and descended into the water in six and a quarter seconds at a distance of perhaps 100 yards. After the machine had been recovered from the water, it was found that a pin had broken in the synchronizing rod which connects the two propeller shafts together, and that the counter, which showed 495 revolutions of the propellers, had been caused to register [p109] inaccurately on this account. The balancing of Aerodrome No. 6 had been made the same as that of No. 5, but in No. 6 the line of thrust was twelve centimetres higher, and this fact, which had not been taken into account in determining the proper balancing for No. 6, seemed to be sufficient cause for the aerodrome coming down into the water so soon after being launched. Darkness had descended before the aerodrome could be recovered and prepared for a second trial. On the next day, November 28, a high wind prevailed in the morning, but in the afternoon it became comparatively calm, and No. 6 was launched at 4.20 p. m. under the same conditions as on the preceding day, except that the float, which weighed 275 grammes, was moved back from the bowsprit eighty centimetres in order to make the machine lighter in front. The aerodrome was launched at a steam pressure of not much over 100 pounds, the air draft for the burners being temporarily bad. The midrod made an angle of approximately three degrees with the horizontal. On account of a slight rain, which had occurred just before the machine was launched, the wings were wet and the weight of the entire aerodrome was doubtless as much as twelve kilos. Immediately on being launched the aerodrome started directly ahead in a gentle south wind, moving horizontally and slowly turning to the right and appearing to approach dangerously near to some thick woods on the west shore. However, it fortunately continued turning until it pointed directly up the beach with the wind in the rear. It then moved more rapidly forward, dipped and rose but once, and this very slightly, and continued its remarkable horizontal flight, varying not more than two yards out of a horizontal course, and this only for a moment, until it finally descended into the bay at a point nearly in a line between the house-boat and the railroad station at Quantico. Upon being recovered, it was found to be absolutely uninjured, and another flight would have been made with it immediately but darkness had descended. The time of flight, as determined independently by