398 
THE MECHANISM OF BICYCLES. 
Elliptic (Fig. 1). 
ment of the levers the pedal follows an elliptical path instead of a cir¬ 
cular path. The inventor claims that by doing so he has cut out those 
portions of the circular path which are traversed by the pedal when 
passing over the dead points common to all circular movements—and 
he claims that in consequence the power required for a 70 gear 
on an Elliptic is equal to that required for a 50 gear on an ordinary 
chain machine. 
This, however, is assuming that the 
statement “that no effective work is 
being done when passing over those 
portions of the circular path which 
have been cut out 33 is correct. On 
examining the diagram ( B .) it 
will be seen that there is no t point 
much less two arcs of 36° each where 
effective tangential force is not being 
applied. 
What, however, is perfectly true is 
that the dead points on the pedal 
path are not passed over simulta¬ 
neously, i.e. the one at the top is 
passed over before the lower one is 
reached, and this can be appreciably 
felt when riding the machine. 
Varying leverage is also obtained, 
the greatest being about the middle 
of the down stroke. The velocity of 
the pedal is variable approaching what 
