May. 1894. WIND AND FLIGHT. 345 



Altitude. Velocity of wind per minute. Altitude. Velocity of wind per minute. 



2 inches. 515 feet. 4 ft. gi8 feet. 



1 ft. 736^ ,, 7 ft. 6 in. i,02r ,, 



2 ft. 770 ,, 



A smaller series of similar experiments carried up to a height of 

 10 ft. 6 in. showed the same tendency. For greater altitudes the 

 anemometer was to have been run up the string of a kite by means 

 of a second string working through a pulley. But, unfortunately, an 

 accident to the anemometer after a few trials made this method for 

 the time impossible. We then fastened the kite to a spring balance 

 and observed the pull at different heights, using a sextant to discover 

 the exact elevation. Owing to alternating hurricanes and calms all 

 work of the kind was often out of the question, and it is much to 

 be regretted that we had not time to repeat the experiments. They 

 seem to show, however, that there is a steady, though diminish- 

 ing, increase up to a height of 240 ft. The pull registered at 357 ft. 

 strikes the only false note in the scale, and when that was measured 

 there was a drop in the wind that was perceptible to ourselves. 



204 ,, 18 ,, 



At low levels the jerking of the kite was a difficulty ; there is 

 also the question whether the greater length of string carried as the 

 kite mounted higher may not have to some extent modified the 

 results. Probably, however, the error due to the latter course was but 

 slight. 



Since making these experiments with a kite, I have tried the 

 plan of letting go a number of small balloons, inflated with hydrogen 

 gas in different degrees and allowing them to race ; the larger rising 

 to a height of 500 ft. or more, quite outpaced the lower. But as far 

 as I could judge, small differences of elevation at the higher levels 

 did not much affect the velocity. It would seem that larks in 

 mounting continue to face the wind when they are too high to derive 

 any benefit from it. 



w 



G ^-->^ j^^^r --^1 ^>^i --.I ^.^ 



W = Direction of wind. G = Line of gull's flight. 



While at New Romney I saw two illustrations of the cleverness 

 of birds in turning the comparative slowness of the lower currents to 

 account. Some gulls, wishing to make headway against the blizzard, 

 flew so close to the ground that their wings almost touched it. On 



