AT MUNICH, 1840, 1841, 1842. 617 
But if we assume, with Mr. Lloyd, that the magnetic force in- 
creases uniformly towards the two extremities of the bar, i. e. that 
Vdm= Az dz, we obtain 
3 (9 72 _ 3] 1 iat 27 je ye 4 133 ny 
Sar 9 (24 hig and g = 355 / Et tage! , 
Then if e = 4land/' = 1, 
4. — — 0-000415. 
é 
In the first case the error in the determination of i by neg- 
& lecting =? will have been sii 3 in the second case _— . Ac- 
cording to the most exact experiments hitherto made, the first 
hypothesis gives too large and the second too small a ratio, but 
at any rate we see that the third member must not be neglected 
in the development. 
To show this experimentally, the following observations were 
made ; 
Distances. Deflections. 
0 1 
BeeBOOR gigs rs Spel GB. 28 kG 
MMOMIG 1h dan eA ok RG AS 
POOOOR il a) 22 ak AO SRLS 
ORD GIy aah nt isune te: Og 3 Ok 
eee Ee hea. a 
7-99973 oi Pal gede AG 
The deflections are the means of two series of experiments 
reduced to equal intensity and equal temperature. If we put 
yp ey 
M f 
log 2 x= log e* sin + “at - 
we find 
pl = —0:0295 
q' = + 0°3600, 
log 2 = = 1°37582 
137585 
1°37580 
1°37581 
1°13582 
1°37583. 
| 
| 
| and the several deflections give the following results:— 
) 
