148 <A. D. Bache on Magnetical Observations in Maine. 
Annual effect of the secular change. 
1861—1860, —2'1 
1862—186l, —2°5 
1863—1 862, —O0?2 
1864—1863, —2-0 
Mean. a a 
On the average, therefore, the annual diminution is very 
nearly 1’. 
Annual inequality of the dip.—If we take the monthly means 
1860 
n. g 
between 1860 and 1864 is —0’-90, about half that of Eastport. 
A + sign indicates greater dip, a — sign less dip than the 
normal value. 
yrerth: gate Corrected dip. — gga si : 
change. Eastport.’ | Toronto. 
’ ° i ‘ a / 
Jan., 7650-4 | ~O'717 | 75496 -v6 | -03 
Feb,, 0°63 49° -0°5 -0°3 
March 50°9 -0°49 50-4 +02 +071 
April, 51:2 -0°35 50°8 +06 +0°3 
May, 49°8 -0-21 49°6 -06 +0rL 
June, 49°6 -0-07 49-5 0-7 -0°5 
July 50°1 +0-07 0-0 ~05 
Aug,, 51-0 +0°21 51-2 +10 +0°1 
Sept., 5U7 +0°35 51-0 +0°8 +06 
Oct., 50°7 +049 51:2 +10 +05 
Nov., 494 +0°63 50-0 -0°2 -O1 
Dec., 38 +0-77 49-6 -0°6 -01 
Mean, 76 60:2 
by the annexed diagram. The range of the inequality at 
oronto is less than at Eastport, where it hardly reaches sae! 
5 Se ee ee ae a ds ee 
