150 A. D. Bache on Magnetical Observations in Maine. 
In computing the last column the wanting values for 1864 
been supplied by interpolation. In July 1865, from ob- 
da 
referring this to the annual mean we subtract 0:006 and obtain 
for 1865 the value 3-313. 
"senal change of the horizontal force—Examining the annual 
ns we notice at first a diminution of the force till the begin- 
fic of the year 1862; the force after this date shows an 
annual increase of 0-0012 parts of the force. In a previous dis- 
rae (Coast Survey Report 1861, Appendix No. 22) the hor- 
zontal force along the Atlantic coast was found to diminish 
annually 00011 parts of the force. This ee according 
e on ti observations, has now ceased, and changed to 
vations, where it took aie cae to G. T. Kingston, 
Director of the Omeeratiry in 1860, which is the year of min- 
imum force. At Toronto the present annual increase amounts 
to 0 0010 parts of the force 
We have further from the Eastport observations the following 
table of the total force, F=H sec I. 
5 F, 
1860, 75° 53/1 3°307 13°56 
1861, 75° 51-0 3°307 13°53 
1862, 75° 48/5 3°303 13-47 
1863, 75° 48'3 3°310 13°50 
1864, 75° 46-3 3313 13-48 
5, = 
Florida, it appears that both the horizontal and total forces 
were diminiahe 
main “year is midway between the extreme years ; "the series 
there extends over nine years, between 1856 and 1864. 
