H. Skey, — Introduction of the Gyroscope in Aerial Transit. 179 



tlae metliocl of working the feet may not be undesirable. If the broad pedal 

 have the middle portion removed, and another pedal be inserted and made 

 to work loosely ou the same fulcrum, a double or rather quadruple pedal is 

 formed ; the toiD of this middle pedal is also connected by rods to the vertical 

 axes of the tension wheels but by additional cranks placed on the opposite 

 sides of the centres. In this manner the feet can reciprocate with one 

 another as in walking or similar to their action in bicycles, and in a great 

 variety of ways reciprocate with the arms. 



This is all the machinery absolutely necessary for the purpose of elevation, 

 and, as before remarked, the extra power required for progression and steering 

 is comparatively small and can easily be api^lied as shown in the di-awing, 

 fig. 5, in which the axis of the upper tension wheel passes through the 

 tubular axis of the lower one, and the framework or car is placed below ; a 

 horizontal axis is also shown as receiving motion by bevelled wheels, thus 

 turning the vertical tension wheel, the vanes of which are set to about 20° 

 and act as a screw propeller ; while an expanding and completely adjustable 

 fan in the rear acts as an auxiliary in steering, for it must be borne in mind 

 that the sectional area of the machine is very small and in fact approaches 

 to that of discs x^rogressiug edgeways. 



A bird in full speed sailing through- still ah' may be likened to the keel 

 of a ship cutting through the water ; the permanency of its direction must 

 be very great. This i^ersistency of its direction is, I think, made use of for 

 buoyant purposes in high winds hi a way that appears hitherto to have 

 been overlooked. For instance a bird, in two parts of its evolutions, is 

 travelling transversely to the direction of the wind, and when in these 

 positions it can often be observed to elevate the tip of that wing on which 

 the wind first impinges, while at the same time the other wing is slightly 

 depressed. The under surface of the wings thus receive the wind, which is 

 thus transformed into an elevating force ; it is clear that a very long sweep 

 can be thus made, for there is no head wind to impede the bird, but 

 only the ordinary resistance of still au' to be overcome. In wheeling 

 in the air, it may also be observed that, as soon as the tip is brought 

 down from the elevated position to the horizontal, the bhd commences 

 flapping its wings. Every current of air can thus be utilized by the 

 bird, which does not appear to fly long dhectly against the wind, but 

 it wheels and tacks to prevent fatigue. In fact, many sea-bnds appear 

 to fly with greater ease and swiftness when a stifl' breeze is blowing, 

 and it may be observed that they keep continually on the wing in 

 gales, but rest much in calms as they sooner tire. When a bird has 

 been elevated whilst sailing transversely to the wind as alluded to above, 

 and also possibly^^wlien sailing a short time against the wind, it can then, 



