J ^2 -^X THE ELECTRIC COLUMN. 



each wire being movable, I could bring the two balls in 

 front of the instrument, within the distance of each other 

 that luight be found convenient; and I suspended, by a 

 silk tliread, a small gold beacU which I could easily bring 

 between the balls, either at the middle distance, or nearer 

 one than the other. 

 Unsuccessful The apparatus being thus prepared, I tried for a long 

 trials wiih an time to make it answer my purpose, but without success. 

 When the two balls were near each other, the bead struck 

 them alternately with such a rapidity, that it was impossible 

 to count the number of oscillations in a determined time; 

 a necessary condition for my purpose. I increased the dis- 

 tance of the balls, but I was disappointed in a different 

 manner: when the bead was equally attracted on both sides, 

 it sometimes remained motionless for hours in the middle 

 of the interval ; and when the attraction became stronger 

 on one side, the bead, drawn that v*?ay, struck one of the 

 balls, some oscillations then began, still too rapid and very 

 irregular, but at the end of a little time, they ceased again^ 

 the bead remaining motionless at the middle point. I tried 

 ▼arious distances of the balls, and also different degrees of 

 approximation of the bead to either of them : sometimes 

 there was an appearance of success, but at last the bead 

 was again at rest in the middle space, or it shcck to one «f 

 the balls. This want of success persuaded me, that a neu^ 

 <ra/ pendulum, such as was the 6efl(^ suspended by a sil/e 

 thread, could never answer the purpose of the regular 

 strildngs, which were necessary ; that the bead was to be 

 connected, by a metallic wire, with one of the extremities 

 of the column, near a ball united with the latter, and to 

 strike against another hall connected, either with the other 

 extremity of the column, or with the ground; the latter of 

 which modes I first adopted. 

 \lr. Foistor But before I proceed, I must mention, that while I waa 



had succeeded p,, i gd in these trials at Windsor, Mr. B. M. Forster had 

 with a longer » •' 



column, to pro- succeeded at Walthamstow, near London, with a power of 

 dure a conti- j^qq cjronps of the same diameter as mine, divided into 

 tuial chime, , , , i -i i • ,. 



three chapiets, as descnben \n my first paper presented to 



the Royal Society, to set in motion a brass ball, suspended 

 by n silk thread between two STriall insulated bells, connected 



with 



