498 
PROFESSOR A. SCHUSTER OH THE DIURNAL 
In the triangle ONE, we know, from Table XX., the ratios 
also the angle 
o 
Write 
ViE : OY, = HiK : OH^ = OH3 ; OH^ = c, 
V,N : OYi = OV3 : OVi = c, 
NV^O = YiOH^ = a. 
NOYi = 6»; EOY^ = 9'; ONY^ = ; OEY^ = f. 
The triangles OY^^N and OY^E give ns the equations 
tan h {<fi- 9) = ^ cot ^ ^ 
tan I (cj)' - 9') = tan ^ . 
(<^ + 6') = 77 — a, 
(</>' + O') = a. 
These equations determine 9 and &, and hence the required angle y = 9 9' also 
OE : ON = sin ^ : sin (j)\ 
In Table XXII. the angle y and the ratio ON : OE : = r have been calculated 
for n = 2. Table XXIII. gives the corresponding quantities if the indueing solid 
harmonic is of degree 4. 
Table XXII.—Comparison between resultant vertical force as regards magnitude and 
phase when induced currents are taken into account and vertical force calculated 
on the assumption that the whole is due to an outside effect. The inducing 
potential is a solid harmonic of degree 2. 
d. 
Eediiction in 
amplitude. 
r. 
Change of phase. 
7- 
1^- 
1 
•9981 
2 43 
3-70 X lOit 
5 
•9565 
13 02 
7-40 X 1013 
10 
•8589 
23 10 
3-70 X 1013 j 
20 
•6705 
34 03 
1-85 X 1013 
30 
•5510 
38 12 
1-23 X 1013 
40 
•4762 
40 16 
9-25 X 1013 
50 
•4261 
41 10 
7-40 X 1013 
100 
•3004 
43 08 
3-70 X 1012 
