324 



H. NAGAOKA. 



of the appnratiis. On a firm stand furnished witli three levelling 

 screws (III), two stout pillars (pp) were erected. A cross bar of wood 

 (hh) was fixed to these pillars. At the middle point of the cross piece, 

 a torsion circle (t) Avas attached, wdth an arrangement for fixing the 

 wire. Below this stood a magnetizing coil (c) on an auxiliary stand. 

 To keep the wire twisted, two stout rods (rr) were raised vertically 

 from a thick brass plate of circular shape, which was screwed to the 

 stand (s). These rods were fastened to alidades, which were movable 



Fig. 1. 



^ 



^ 



m. 



m 



^T 



^T 



p 



Fig. 2. 



D 







'W 



about an axis at the centre of the plate. Thus the rods could be fixed 

 in any desired position, and made to catch the cross attached to the 

 lower end of the wire. The cross was made of tw(^ rc^ds at right 

 ano-les to each other. The A-ertical rod had an arrano-ement for hold- 

 ing a small plane mirror (7h). The horizontal rod was capable of 

 sliding in the vertical, «and could be clamped firmly to it by means of 

 a screw. A vane (v) was attached to the lower end of the vertical 



