8 Trans. Acad. Sci. of St. Louis. 



disturbed by the movement of near-by objects. Atten- 

 tion was called to this phenomenon and to the " ball- 

 lightning" discharge in my paper before the Interna- 

 tional Congress of Arts and Science in 1904. 5 These phe- 

 nomena indicate that the negative current is the agent 

 which seems to be concerned in electrical action. On the 

 negative side of the machine, negative discharge to the 

 ground is accompanied with leakage from the machine 

 terminals and line to the surrounding air. On the posi- 

 tive side a negative flow from the ground to the machine 

 seems to be accompanied with an inflow or leakage of 

 negative electricity from the surrounding air to the posi- 

 tive terminals and line. There is nothing to make neces- 

 sary the assumption that any positive discharge is taking 

 place through the conducting wires in any of the experi- 

 ments here described. The positive ions which appear 

 in the gases of the Geissler and Crookes tubes are gaseous 

 atoms from which negative electrical particles have been 

 separated, by reason of a forced circulation of these neg- 

 ative particles through the entire circuit. 



In order to examine more directly the nature of the 

 discharge from or towards separately grounded lines of 

 the influence machine the method here to be described 

 was employed. One terminal of the machine was con- 

 nected with an earth connection (G 1? Fig. 1) in the yard 

 outside of the building, a spark gap of one or two centi- 

 meters being made at the machine terminal. The dis- 

 charge from the other terminal across a spark-gap of 

 about 30 cm., was led to an independent ground (G 2 ) on 

 an adjoining side of the building. The conductors in both 

 lines were No. 8 copper wires. The line having the long 

 spark discharge through it contained a high resistance 

 R, near its ground end. This resistance was composed 

 of three or four strips of porous cloth bandage, placed in 

 parallel, their ends being placed in tumblers of salt 

 water. This resistance could be varied by changing the 



6 Present Problems. Vol. IV, pp. 92-101 of the Proceedings. 



