On the Energy expended in Propelling a Bicycle. 309 
which the foot travelled before the indicator apparatus was attached, with points 
marked on it corresponding to the points numbered in the same way on the circle 
of the figure, which is the curve through which the end of the crank of the bicycle 
travels. And again the same numbers on Figure 3, Pl. 39, mark the points of the 
indicator diayram corresponding to those positions of the crank. These on the 
“reduced” diagram, (Pl. 40, Fig. 4,) are made proportional to the net vertical descent 
of the foot in its oval motion. The area of the “reduced” diagram, Figure 4, will 
then be the energy supplied by the right foot of the rider during one revolution of 
the bicycle wheel, on the hypothesis that he presses vertically on the treadles ; and 
the whole energy exerted by both feet will of course be twice this. 
The following results were obtained with this apparatus in the winter of 1881- 
82, and the diagram represented in Figure 3, Plate 39, is copied from that produced 
in experiment 6. 
TABLE I. 
SERIES I. of Observations made in Winter with the Recording Spring attached to the top of 
the Lever of the Bicycle. 
No. of pak eee Velocity | Coefficient 
Experi- aaa BECrE a in Miles , of Observations. 
ment. per Hour. |Resistances. 
1 21,800 3,500 9-6 qs On wet gravelled pathway in Palmerston-park, 
2 23,700 4,000 10:2 rr Dublin, up a trifling inclination of 1 in 160, 
3 40,500 7,900 er, oe with the wind. 
4 19,200 2,650 8:3 sis 
5 29,500 4,000 8:2 32-5 
6 36,000 5,350 9 ay On the same path, down the incline, and against 
a 38,500 6,000 9-4 or the wind. 
8 38,500 6,500 10:2 oy 
9 41,600 7,400 10-7 qs 
JQ 2 ‘ n is 
iy ae ee ae Bez In the direction of the wind, on muddy rough 
ae ’ Ba G ' 7 z . 
12 38,500 5,350 8-3 ae level road in Palmerston-park. 
13 38,500 4,000 6°25 aT 
i ere on 650 Ba a Against the wind, on the same road. 
16 57,600 7,200 75 x's 
ee 36,000 5,350 9 ae Average of all the foregoing experiments. 
5 Rl 
