446 PHILOSOPHICAL TRANSACTIONS. [aNNO 1747-8. 



commotion was perceptible, if both the observers at d and e, supported by ori- 

 ginally-electrics, touched the conducting wire with one hand, and the water of 

 the New River with an iron rod held in the other ? 2dly, Whether that commo- 

 tion was perceptible, if the observer at E, being in all respects as before, the 

 observer at d, standing on wax, took his rod out of the water? 3dly, Whether 

 that commotion was perceptible to both observers, if the observer at d was placed 

 on wax, and touched the ground with his iron rod in a dry gravelly field at least 

 300 yards from the water ? 



To try the first proposition, several explosions were made with the observers 

 at D and e, touching the water, and standing on wax, with their iron rods in 

 the water; when the observers at both stations felt the electrical shock. 



To try the second proposition, 4 explosions were made with the observer at d 

 standing on an originally-electric, and taking his iron rod out of the water, the 

 observer at e as before. In each of these the observer at d felt a small pulsation 

 between his finger and thumb of that hand, which held the wire. The observer 

 at E felt each of these as strong as before. The 4 other explosions were made 

 without any other alteration in the apparatus, than that the observer at d stood 

 on the ground about 4 yards from the water without any communication with it. 

 The observer at e felt the shocks in his arms as before ; but the observer at d 

 standing on the ground was shocked in the elbow and wrist of that arm which 

 held the wire, and in both his ancles. 



To try the third proposition, 8 explosions were made with the observer at d 

 standing on an originally-electric with his rod in the water of the river as before; 

 but the observer at e was placed in a dry gravelly field about 300 yards nearer the 

 machine than his last station, and about lOO yards distant from the river. He 

 there stood on the wax, holding the conducting wire in one hand, and touched 

 the ground with an iron rod held in the other. The shock was each time felt by 

 the observer at d, but sensibly weaker than in the former trials ; but the observer 

 at E felt them all equally strong with the former; the first 4 in his arms, when 

 he stood on the wax, and touched the ground with his iron rod; the other 4 in 

 his arm and ancles, when he stood on the ground without the iron rod. 



By the experiments of this day, the gentlemen were satisfied that the dry gra- 

 velly ground conducted the electricity as strongly as water; which, though other- 

 wise at first conjectured, they now found not to be necessary to convey that power 

 to great distances; as well as that, from difference of distance only, the force of 

 the electrical commotion was very little if at all impaired. 



In one instance the circuit was formed from the phial by the observer at d and 

 his wire, a line of ground which reached fi"om the station at D to the broken 

 wire that lay on the ground, and so much of this wire as reached to the short 

 iron rod, which touched the gun barrel in making the explosions. This induced 



