92 



Prof. E. Edlund on Galvanic Resistance as 



c and ol and between d and e are as nearly as possible equal. 

 In each of these side-tubes a gold wire is fixed by means of a 



Fig. 1. 



cork and sealing-wax, terminated by a gold disk. On each 

 end of the glass tube a metal cap with a screw-thread is fas- 

 tened, by which the glass tube can be screwed onto the copper 

 tube through which the liquid to be investigated flows into the 

 glass tube. G represents the magnetometer used in the expe- 

 riments, the almost perfectly astatic needle-system of which is 

 suspended by a fine silver wire. The position of equilibrium 

 of the needle-system is almost entirely independent of the va- 

 riations of the earth's magnetic declination-plane, because it is 

 all but exclusively determined by the torsion of the wire. The 

 oscillation-period of the system amounts to about 28 seconds. 

 By a thick copper sheath, which envelops one of the needles, 

 so powerful a damping is produced that the system takes its 

 position of equilibrium after a few oscillations. The reading- 

 off is effected in the usual manner, by aid of telescope and 

 scale. Although the magnetometer might possibly have been 

 made more delicate by another arrangement, it possesses the 

 great advantage of an almost invariable position of equilibrium 

 —a circumstance of great value. In the experiments two of 



