1 7G PROF. TROUTON AND MR. NOBLE OX THE MECHANICAL FORCES ACTINCI 
The lower curve with full line in fig. 8 shows the corresponding magnitude of the 
resultant drift. 
The following table shows the time of day when the drift is entirely horizontal, 
and the azimuth of the drift at that hour, for the first day of every month in the 
^ear;— 
Janaaiy 1st 
February ,, 
March 
April 
May 
June ,, 
July 
August ,, 
Septeinlier., 
October ,, 
November,, 
December 
Orbital motion alone. 
Orbital motion and sun’s 
proper motion. 
Hour of 
horizontal drift. 
Azimuth of 
drift. 
Hour of 
horizontal drift. 
1 
A 1.32 A.M. 
+ 8°4 
3.31 P.M. 
1 
.12.15 „ 
-84 
12.21 A.M. 
r10.20 „ 
+ 65 
1.45 P.M. 
1 
[1.0 „ 
-65 
12.13 A.M. 
J 
r 9.46 „ 
+ 53 
12.45 P.M. 
1 
L 1-48 „ 
- 53 
12.1 A.M. 
1 
rio .2 „ 
+ 52 
12.9 P.M. 
i 
L 2.12 „ 
— 52 
11.29 „ 
1 
r 10.44 „ 
+ 61 
11..50 A.M. 
1 
L 1-5J „ 
-61 
10..38 „ 
J 
rii.4i 
+ 78 
11.47 „ 
1 
[12.45 „ 
-78 
9.7 „ 
j 
[12.13 P.M. 
+ (477+ 5) 
12.15 P.M. 
1 
[11.46 „ 
“ (4~ + 0) 
7.3 „ 
1.1 r.M. 
10.16 
1.46 „ 
9.46 .. 
f 2.15 
1 9.54 
; 1.57 „ 
L 10.40 
{ 
12.58 
11.30 
+ (477 + 23 ) 
-(-W + 2.3) 
+ (477 + 36) 
- (477 + 36) 
+ (4-77 + 39) 
-(477+ 39) 
+ (477 + 30) 
- (477 + 30) 
+ (4-77+14) 
- (477 + 14) 
Best time. 
r.M. 
3.28 .. 
7.6 .. 
I 8.58 .. 
6.25 P.M. 
10.55 „ 
Azimuth of 
drift. 
+ (1-77 
-(i- 
+ (i- 
-(i- 
+ (^ 
-(177 
+ (z'' 
+ (477 
+ (s’^ 
- (-2-^ 
+ (477 
+ (477 
+ 31) 
+ 31) 
+ 141) 
+ 144) 
+ 1) 
+ 1 ) 
+ i) 
+ 5 ) 
+ 114) 
+ 11|) 
+ 244) 
+ 244) 
+ 46) 
+ 46) 
Horizontal 
component. 
180 
180 
180 
ISO 
Magnitude. 
} 
} 
} 
'I 
[ 
} 
} 
} 
miles per sec. 
24-9 
(477 + 63 ) 4 
-( 177 + 63 ) ; 
29-0 
29-8 
26-2 
00 • 0 
15-3 
6-5 
4-0 
11-8 
19-2 
From August to November the best time denotes the hour of the day when we 
O 1 .' 
olfiain the maximum liorizontal component. 'J’he total resultant can never be entirely 
horizontal during these montlis. 
O 
Measurement o f the Capacity o f the Condenser. 
The capacity was measured absolutely on the apparatus designed by Dr. Fleming 
and Mr. Clinton (‘Phil. Mag.,’ vol. 29, 1903). and gave the value '0037 m.f This 
