737 
Centrifugal Force as Geotropic Stimuli. 
And M.E.C. = 0-93. 
C (corrected) — 9-7 mg. 
/ C 
9 * 7 - 
Thus — = io-o, 
CT 
mg. t 
mg 
0 - 97 - 
Experiment 9. May 4, 1912. 11.50 a.m. to 10.20 p.m. 
Temp. = 20 0 C. 
Radius of rotation at middle of box = 20 cm. 
6 = 96°. 
Total period (/+ T) = 11 m. 
R = 3-78. 
Point of equilibrium is 2 cm. below middle of box. 
r = 18 cm. 
Cent, force = 10-35 m g- 
C - 10.39 mg. 
Thus’ 7^ = 
CT _ 
* * mg. t 
o-5, 
0.99 
mg 
IO ’ 39 - 
Experiment 10. Dec. 18, 19 11. 10.19 a m - t0 9 - 4 ° P- m - 
Radius of rotation at middle of box = 30 cm. 
0 = 94 0 . 
Total period (/+ T) = 5 m. 30 s. 1 
t 
TI - 3 °- 
R = 3-03. 
Point of equilibrium is 1-5 cm. below middle of box. 
r = 28-5 cm. 
Cent, force = 10-52 mg. = C. 2 
t C 
Thusy = 11-30, — = 10-52. 
CT 
Experiment ii. Dec. 17, 1911. 11.35 a.m. to 11.30 p.m. 
Temp. = i9°C. 
Radius of rotation at middle of box = 30 cm. 
6 = 94 °- 
1 In this experiment the times were arranged differently. The wheel rotated for 26 s., was still 
for 2 m. 17 s. ; rotated for 27 s., and still for 8 m. It then started rotating again for 26 secs. 
2 When 9 is less than 96°, the resultant of the centrifugal force and gravity is so near the 
former that it may be taken as equal to it. 
