434 PHILOSOPHICAL TRANSACTIONS. [aNNO 1778. 



immediately the point became luminous, and the moveable artificial cloud ceased 

 striking to the ball, and soon returned to its horizontal position as at first. 



Ex}}. 17- The apparatus remaining as in the last experiment, and the two 

 clouds continuing to be charged, he took away the stand with the point; then 

 the moveable artificial cloud was attracted down to the ball, and struck as before. 

 He then placed the stand with the point close to the stand with the ball; on 

 which the point became instantly luminous, and immediately the moveable 

 artificial cloud ceased striking, soon returning from the ball and settling nearly 

 in a horizontal position. Tliere the point carried off the electric fire as in the 

 13th and 14th experiments. 



Observation. — From the 13th experiment, with the point under one end of 

 the moveable artificial cloud, and a 3 inch ball under the other end, it seems as 

 if neither the ball nor point attracted either end; or that they both equally 

 attracted, or repelled each end, as in either case the moveable artificial cloud 

 would remain horizontal. And in the 14th experiment, in order to try whether 

 the point would attract or repel the moveable artificial cloud, the ball was taken 

 away, and only the point was left under one end, as now all the action of the 

 point either to attract or repel would be exerted on that end which was now over 

 the point, and consequently that end should either be attracted down to it, or 

 repelled from it: but from the experiment it appears, that the point drew off all 

 the electricity silently, without either attracting or repelling the end of the 

 moveable artificial cloud which was over it, as it continued horizontal all the 

 time it was charged. 



The 15th experiment was made to see if the ball would either attract or repel 

 the moveable artificial cloud, as in this experiment the ball only was under one 

 end, and every thing else exactly the same as when the point only was under. 

 But here we find the effect of the ball very different from that of the point; for 

 instead of drawing off the electricity silently, as the point did, without attracting 

 the end of the moveable artificial cloud; on the contrar)', the moveable artificial 

 cloud was attracted down towards the ball, till it came within its striking distance, 

 where it discharged its electric fire all at once on the ball with a loud and strong 

 spark. And again, in the 1 6th experiment, where the stand with the point is 

 replaced at the other end, while the cloud was attracted down to the ball, it 

 instantly prevented its striking to the ball by carrying off the electric fire as fast 

 as the moveable artificial cloud received it from the artificial one. And from the 

 17 th experiment we learn, that when the stand with the point was placed close 

 to the stand with the ball, while the moveable artificial cloud was striking to it, 

 the cloud even in this case instantly ceased to strike to the ball, returning from 

 it and soon settling nearly in a horizontal position. 



Exp. 18. Mr. N. took off the cylinders from the ends of the moveable 



