CHARLES B. WARRING. 155 
It is evident that A cannot fall backward or forward, 
since a vertical from it falls between the points Cand B. 
In reference to these, A isin, what physicists call stable 
equilibrim, while in regard to side motion its equilibrim 
is very unstable. The least thing will upset it. 
For experimental purposes, I have hada skeleton 
made the same in form as the last diagram, but strong 
enough to be safely handled. 
The shorter leg is 5 feet long ; 
the other about 7 feet. The lead 
saddle weighs 6 pounds. 
It consists as you see of two long, slender pieces of pine, 
and looks like a huge capital A, the cross piece serving 
merely to hold the whole more firmly together. At the 
apex, or saddle A, I have placed a few pounds of lead 
to represent the rider. 
In the ordinary bicycles there is a large wheel in front, 
and a very small one behind, and the saddle well over 
the former. In these the forward leg A JB, fig 6, is 
much the steeper and shorter. In ‘‘Safety” ’cycles it 
is just the other way. At present we will consider only 
the former. For convenience in handling, and that it 
may be better seen, I place the foot C, the rear one of 
my skeleton frame, on the table, and hold the other, B, 
in my hand, and at the same height from the floor. 
Now notice. The weight tilts toward the east, I quickly 
move the lower end toward the east till it comes under 
the weight. If it tilts toward the west, I move my hand: 
105 
