404 
THE MECHANISM OF BICYCLES. 
Diagram- (i I) 2—The Veeder Cyclometer . 
6 J- revolutions of the spindle for the smaller spur wheel to rotate once, 
but both wheels being keyed together they must revolve together 
and in order to do so the “ fraction ” disc has to give way, i.e., it is 
pulled round a distance equal to the pitch of one tooth every 6-£ 
revolutions. Since it has 23 teeth it follows that the “ fraction” disc 
rotates once in 23 x V revolutions, i.e. once in 145*7 revolutions. 
145*7 x 5 (the number of spokes on the star wheel) = 728*5 
which is the number of revolutions calculated for a 28" wheel 
to move one mile, making allowances for the thickness of tyre 
and variations in air pressure. I found from experience with the 
Standard which allowed 720 revolutions for a 28" wheel that it was 
“out” to the extent of of a mile, a result that agrees very nearly 
with the 728*5 revolutions allowed for in the Yeeder. 
In conclusion, I must leave you, ladies and gentlemen, to judge the 
machines now for yourselves and say if you think you have seen any¬ 
thing to make you desire to change your present form of driving 
mechanism and would only add two words of advice, first that in buy- 
