232 Mr Bevan, A Lecture Experiment to illustrate the effect 



A Lecture Experiment to illustrate the effect of a straight 

 current on a magnetic pole. By P. V. Bevan, M.A., Trinity 

 College. 



[Read 18 May 1903.] 



A simple form of apparatus is represented in fig. 1 for 

 showing the continual rotation of a single magnetic pole round 

 a straight wire carrying a current. The funnel A is attached to 

 a tap leading to a tube B, which is drawn out at its lower end so 

 that its bore is about '5 mm. At about 1 cm. below the tube B is 

 fixed a second tube C of diameter at the top about - 5 cm. and 



Fig. l. 



drawn out at the lower end so that its diameter is slightly less 

 than that of the lower end of B. The lower end of G dips into 

 mercury in a basin D, Leads from a battery dip into the mercury 

 in the funnel A and the basin D. When the tap at the bottom of 



