246 M. Werner Siemens on the 
The increases in magnetism, calculated for 0:001 ampere, 
show here also a small increase with increase of current- 
strength. The maximum increase could not be attained with- 
out unduly heating the coil. 
If the assumption is correct, that nonmagnetic material, in 
the same manner as magnetic material, is filled with pre- 
existing molecular circular currents, it is to be assumed that 
in it, as in magnetic material, there exists a maximum of 
magnetism. An approach to a maximum of magnetization 
must then become perceptible with very great magnetic 
moments of a magnetic field, as in iron. 
In order to investigate this, I placed two prismatic pieces 
of iron on the poles of the horseshoe-magnet described, which 
could be made to approach each other closely. The parallel 
surfaces opposed were reduced to one square centimetre. The 
increase in magnetic moment of the magnetic circuit was 
measured for increasing current-strength. The results are 
given in the following Table :— 
TABLE V. 
_ || Horseshoe closed || Poles fitted with prismatic pieces of iron. Their 
a by iron plate. distances apart :— 
2 
BS Tecra 0-1 mm. 1 mm. 35 mm. 
ne Deflec- k 1 ||\Deflec-| Increase || Deflec-| Increase ||Deflec-| Increase 
= tion. 7 - oe tion. | per z3_ || tion. | per z3q || tion. | per z35 
a Poe alnpere. ampere. ampere. 
a Bok St SN ES | 
ie 2. 3. 4, 
O11) 219 19:9 80 72 49 4:4 37 34 
O2U (20) b0z1 193 | 11:3 107 58 78 4-1 
0:°53|| 1708 | -380°9 620 | 13:3 313 6-4 217 4:3 
0-85)| 2124 13:0 1020 | 12:5 524. 6:6 362 4:5 
1:06|| 2292 8-0 1276 | 12:2 680 TA 460 4:7 
2°12|| 2640 3'3 2028 fal 1344 6:3 942 4:5 
3°18]| 2760 ileil 2400 3°5 1908 53 1380 4-1 
4:24|| 2840 0-7 2620 21 2340 4°] 1820 4°2 
5:30]; 2870 05 2728 10 2576 2:2 2172 33 
6°36|| 2980 0-4 2800 0°7 2700 | 1-2 2440 2°5 
The pole-pieces were placed at. distances of 0:1, 1, and 3°5 
millim. apart. The current-strength was increased to the 
highest possible value, 2. e. 6 amperes. As seen from column 
1, with a closed magnet the maximum increase occurred with 
a current of only 0°2 ampere. It is remarkable that with 
approximated pole-pieces the turning-point for each distance 
