J 64 *^ THE EtteCTRiC COttJMNi 



spring; but it was too late for the most important obserirai 

 tions; especially as the apparatus itself was far from being 

 settled. Before that season, the effect of the column had 

 been so great, that the gold leaves of the electroscopes, ei- 

 ther on one side or the other, sttuck sometimes in the after- 

 noon 60 times in a minute, even in glass tubes of 1| inch 

 diameter; but now they seldom struck more than once in 

 a minute, sticking always as usual (which was the reason 

 why I had given up the gold leaves) : however the effect was 

 still sufficient to try the new apparatus* 

 Theb^Uwould This again gave me much trouble: for though at first it 

 ^" ' '* * appeared to answer ray purpose; as the gold bead, receding 

 from the ball 15, struck the ball 18, fell and returned, 

 again, with the usual changes in the frequency which were! 

 to be the object of observation ; the head at last stuck to 

 the ball 18. I tried whether, by increasing the distance of 

 the latter, the bead,, thus drawn farther out of the vertical 

 line, would have more power to resist the cause of its stick- 

 ing ; which it is difficult to understand, as it is not the case 

 when set in the same motion by a mechanical impulse. The 

 strikings were less frequent ; not so however as to prevent 

 the observation, if the sticking had been prevented ; but it 

 again took plade^ and even more easily, as the bead arrived 

 more slowly in contact with the balL I did not succeed 

 better by increasing the power (in a manner which I shall 

 explain hereafter), though I could produce the strikings at 

 a greater distance; so that, after much labour, I had some 

 time despaired of success, when another idea occurred to 

 me, which however did not succeed at first. 

 Attempt to The general idea was, to produce the strikings, not by the 



•trikingby the ^^^'^ itself, but by its silver wire, in a part at some height 

 wire, not by the above the latter, by the wire meeting there the edge of a 

 horizontal brass lamina in communication with the ground? 

 in order that the wire being bent at that point, by the bead 

 moving still farther, the latter should have a greater angu- 

 lar motion from that point, by a shorter radius, and have 

 thiis a greater tendency to fall bacjc after being discharged ; 

 suppressing at the same time the baL 18, to which it stuck: 

 but by this suppression, the motion was so much diniinish-« 

 ed, that 1 was obliged to use again the ball; and then the 



wir^ 



