346 THE BORDERLAND OF SCIENCE. 



It encourages confidence in the attempts now being- 

 made to solve the problem of aerial locomotion, 

 that they ' are tentative, founded on observation 

 and experiment, and not on vague notions respecting 

 the manner in which birds fly. Fresh experiments are 

 to be made, more particularly on the supporting power 

 of the air upon bodies of different form, moving with 

 different degrees of velocity. These experiments 

 are under the charge of Messrs. Browning and 

 Wenham, of the Aeronautical Society, whose skill in 

 experimental research, and more particularly in inqui- 

 ries depending on mechanical considerations, will give 

 a high value to their deductions. The question of 

 securing the equipoise of flying-machines has also 

 received attention ; and it is probable that the principle 

 of the instrument called the gyroscope will be called 

 into action to secure steadiness of motion, at least in 

 the experimental flights. What this principle is need 

 not here be scientifically discussed. But it may be 

 described as the tendency of a rotating body to preserve 

 unchanged the direction of the axis about which the 

 body is rotating. The spinning-top and the quoit 

 (well thrown), afford illustrations of this principle. 

 The peculiar flight of a flat missile, already referred to, 

 depends on the same principle ; for the flight only 

 exhibits the peculiarities mentioned when the missile 

 is caused to whirl in its own plane. But the most 

 striking evidence yet given of the steadying property 

 of rotation, is that afforded by the experiments of 

 Professor Piazzi Smyth, the Astronomer Koyal for 



