4 
40. A. D. Bache on Declinometer Observations, : 
of the diurnal amplitude, yet giving proper weight, (on account 
of deficiencies,) the minimum number of disturbances falls 
the year 1843. 
f we distribute the disturbances, 1,942 in number for the 
even hours, according to their respective hours of occurrence, 
we find the following ratios: 
RATIOS. 
Philadelphi } Total 
soe aa Ww. | E. number, 
ham 
0 (194) 0°82 1-20 162 
> Os 118 1:16 189M 
As 108 0°96 168 
eee 1°35 080 173 
oe 129 0-70 161 
” 1:32 0°88 178 
. Noon “ 1:13 O71 150 
a 095 0°67 133m 
2 1:07 0-78 148 
1 ™ O8T 090 143 
207. ¢ 040m 166M 167c 
22 (193) 0-54 1:58 170 
The numbers in each column show a regular progression; the 
disturbances, irrespective of their direction, have a minimum at 
2P.M., an i A. M., (at Toronto the respective 
hours are 2 Pp. M. and 22 Pp. m.). The principal contrast is be — 
tween the hours of the day and the hours of the night. In the 
, and the exact coincl 
by General Sabine for 
deflections at the other station, and vice versa. This contrast 
therefore holds good for Philadelphia as well as Toronto. 
f we classify the disturbances according to their amount, we 
obtain the total aggregate and mean values of a single disturb- 
ance in the different years as follows: 
~ Mean value. 
in acefe diviatone| \Mee® valde. We 
1840 670 652 7-20 
1841 661 593 1-07 
1842 611 5°53 6°70 
1843 4°85 4°85 4°85 
1844 621 621 621 
1845 6:02 5:25 
