H. Sxey.—Introduction of the Gyroscope in Aerial Transit. 179 
the method 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 on the same fulerum, a double or rather quadruple pedal is 
formed ; the top of this middle pedalis 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 applied as shown in the drawing, 
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 progressing edgeways. 
A bird in full speed sailing through still air may be likened to the keel 
of a ship cutting through the water ; the permanency of its direction must 
be very great. This persistency of its direction is, I think, made use of for 
buoyant purposes in high winds in 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 i 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 air 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 bird commences 
flapping its wings. Every current of air can thus be utilized by the 
bird, which does not appear to fly long directly against the wind, but 
it wheels and tacks to prevent fatigue. In fact, many sea-birds appear 
to fly with greater ease and swiftness when a stiff 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 when sailing a short time against the wind, it can then, 
