154 



KNOWLEDGE & SCIENTIFIC NEWS. 



[July, 1904. 



Aeroplane 



Experiments. 



Bv jMajor B. Baden-Powell. 



In the last number of " Knowledge & Scientific Xews" 

 was described the apparatus which I have erected at the 

 Crystal Palace for givinj,' initial impulse to a man-carrying 

 aeioplane in order to test the balance and steering arrange- 

 ments. Since this account appeared many more e.xperi- 



very slowly. This difficulty was, of course, soon over- 

 come by planing away about J inch from the inside of 

 the rails. Then various trials with different forms of 

 lubrication for the runners showed difficulties with this 

 method, and resulted in the application of small wheels 

 to the sides of the boat in place of the oak runners. The 

 track itself was also altered, as it was found that the 

 "take off" at the lower end was rather too steeply in- 

 clined and detracted from the speed. On June 8 the first 

 trials were made with a man in the boat, and several 

 fairly successful descents were made, bolh by Mr. 

 J. T. C. Moore Brabazon (who has kindly given me 



Ready to Start. 



Pho:u by Kussell. 



ments have been conducted, although we have learnt 

 what a vast amount of small details need alteration and 

 adjustment before good resultscan beobtained. Repeated 

 trials showed that the boat sliding down between the in- 

 clined rails did not nearly attain the speed which it should 

 have accomplished according to theory, and it was only 

 after many days that one cause of this was discovered. 

 Although the gauge of the track had been carefully tested 

 on completion, and though the inside of the rails appeared 

 to be perfectly straight, a subsequent measurement of 

 the gauge, after the structure had been subjected to many 

 days' alternate sunshine and rain, proved that the wood 

 had swollen and warped so that there was a slight con- 

 traction about halfway down. This was just sufficient 

 to cause the boat, in its descent, to become slightly 

 jammed between the rails, but not sufficient to stop its 

 way, so that to all appearances the apparatus simply ran 



most valuable assistance in these trials) and by myself. 

 The size of the aeroplanes used on this occasion was 

 insufficient to make a good glide, the total weight of 

 the apparatus amounting to some 270 lbs., and the area 

 of the aeroplanes (each 12 ft. by 5 ft. 6 ins.) to only 

 132 square feet. It was considered desirable to try the 

 apparatus with this small aeroplane, with the object of 

 testing the strength of all parts, and in this respect the 

 results were most satisfactory. The boat, consisting of 

 rough boards and battens screwed and nailed together, 

 covered with canvas, stood a lot of very rough usage, and 

 scarcely suffered at ail from its plunges into the water. 

 The aeroplanes were of thin cambric, stretched on 

 bamboos of about liins. diameter at the butt ends. These 

 were fixed to the boat, but otherwise not stayed or trussed 

 in any way ; and though they bent upwards considerably 

 during the descent through the air, pro\ed to be amply 



