158 ANNUAL. REPORT SMITHSONIAN INSTITUTION, 1910. 



THE NEW BLfiRIOT AEROPLANE. 



The B16riot IV, in the form of a bird, of which we spol^e at length in No. 4 

 of the Bulletin of this year, does not appear to give good results, perhaps on 

 account of its lack of stability, and Bleriot, instead of trying some modifica- 

 tions which might remedy such a grave fault, laid it aside and at once began 

 the construction of a new type. No. V, adopting purely and simply the arrange- 

 ment qf the Ajnerican, Langley, which offers a good stability (see Bulletin 

 11-12, Nov. to Dec., 1905, pp. 187 and 188). The experiments, which were com- 

 menced a month ago, were first completely negative, because the 24-horsepower 

 motor would not turn the propeller, which was 1.80 meters in diameter and 

 1.40 meters pitch. By advice of Capt. Ferber, Bleriot reduced the pitch of his 

 propeller to 0.90 meters, so that the motor could give all its force. 



This modification was an important one for his aeroplane. From thac 

 moment every trial marked an advance. On July 12 he made a flight of 30 

 meters, and the aviator was able to show that the lateral stability was per- 

 fect. On July 15 the trial was made against a wind of 6 miles an hour, but 

 gave good results. He made a flight of 80 meters, showing, however, that the 

 hind part of the aeroplane was too heavy. In this flight he arose as high as a 

 second story and on landing the wheels and one propeller were somewhat 

 damaged. 



On July 24, repairs having been completed, a new trial was made. This 

 time, in order to remedy the defect in the balance, Bleriot had moved his 

 seat forward about 80 centimeters. The correction was too great, for on that 

 day the aeroplane, although the hind part arose, was not able to leave the 

 ground. On July 27, after having mounted the seat on wheels, as in skiffs, 

 Bleriot resumed the trials and made a flight of 120 meters, at first moving his 

 seat back and then, after getting started, bringing it forward. Bleriot had 

 not provided this aeroplane with an elevating rudder, but, following the ex- 

 ample of Lilienthal, changed the center of gravity of the apparatus by mov- 

 ing his own person, and after having established the proper angle remained 

 immovable on his seat. In order to arise or descend the aviator made use of 

 the spark lever, thus varying the number of turns of the propeller. 



During a second trial on the same day, having accidentally reached the limit 

 of the aviation field, Bleriot, without allowing himself to be surprised and 

 obliged to descend, decided to attempt a turn by maneuvering the steering 

 rudder and to return again to the center of the field. With marvelous pre- 

 cision the aeroplane began to describe a circle of about 200 meters radius, in- 

 clining as if on a pista cidistica. Having finished the flight he quickly re- 

 gained his balance, still in the direction of the wind, but on account of a slight 

 movement of the aviator the aeroplane fell to such an extent that he was 

 obliged to land. He landed gently and without shock, rolling on his wheels. 



On August 1 he made another flight of 100 meters in 6i seconds, and on the 

 6th one of 265 meters, with one interruption. While the attention of the pilot 

 was distracted for a moment the aeroplane, which was flying at a height 

 of 2 or 3 meters above the ground, touched the soil with its sustaining wheels 

 at the end of 122 meters, and then, immediately arising, covered the remaining 

 143 meters at a height of 12 meters. Bleriot, moving forward too quickly, 

 caused the aeroplane to descend swiftly to the ground, and the shock broke the 

 axle and the blades of the propeller were bent. In order to confirm this 

 account we reproduce what was said in the Auto of August 7, 1907: 



" M. B16riot, continuing the trials of his aeroplane yesterday, surpassed the 

 superb results which he had already obtained. The trial took place at 2 o'clock 

 In the afternoon on the aviation field of Issy. After a sustained flight of 



