BIFILAR OR HorIzZONTAL FoRcE MAGNETOMETER. xhi 
TABLE 6.—Observations of Deflection of the Balance Magnet suspended horizontally 
by the Declinometer Thread, January 10, 1848. 
M i fy 
Distance of | Observed aed pees Value of | Resulting | Temp. of 
i Deflec- Melee for One 
ftons tion. Torsion, Se. Div. 
Se. Div. Se. Div. y 
26-96 
23.78 25-37 | 1:00851| 25-59 0-746 
Se. Diy. 
56-83 
48.09 | 22°46 52-91 
129-88 
en bee 118-43 
From the deflections, Table 6, and the formula 
M ~pP q 
x= 7 tan u a+3 + =a) 
we find 
log = =9'13614 — log p, = 988791 — log g, = 9°11654 
From the previous equation, 
M 1 
banat Soi 
A1+4,h 
the values of z , Py and q, given above, and the values of r from the first column 
of Table 5, being substituted in this equation, the values of log tan u, column 12, 
have been obtained. 
59. If Y, the vertical component, be substituted for X, in equation (2.), No. 34, 
we shall have, since Y = X tan 0 
AWo ts WE nh 
Y Sa Gnas gt ga? 
whence 
Ae tan w 
n tan 6 
: AY : ent 
where k is the value of rr for one micrometer division, uw and n are the corrected 
horizontal and vertical deflections for the same distance 7; the former in angular 
MAG. AND MET. OBS., 1845 AnD 1846. l 
