14 



Mr. 0. J. Lodge. Experiments on 



[June 4 y 



discharging tongs held round the lip. Probably the sharp edges of 

 the tinfoil contributed to this effect, possibly also dust or other 

 specks on the surface of the glass, or it may be the action of the air 

 film itself, but it seems as if the extremely small inductance of such a 

 path likewise aids what, if it is to occur at all, must take advantage 

 of a flood tide, a millionth of a second's duration. 



CONFIRMATORY EXPERIMENTS (6th March, 1888) . 

 15. Two similar jars, each with dischargers, were connected as- 

 shown in fig. 6. 



I'm. 6. 



A spark at A now caused the distant jar to overflow easily, but had 

 no effect on the near one. Similarly, a spark at C caused the jar 

 distant from C to overflow easily, but had no effect on its own jar. 



An A spark never caused a spark at C. Sparks occurred either at 

 A or at C, according to which happened to be the narrowest gap, but 

 not at both ; and it was always the jar most distant from the spark 

 that overflowed its lip. 



16. The explanation probably depends upon the fact that when a 

 spark discharges its near jar the charge from the distant one rushes 

 forward, but, not being able to arrive in time, surges back violently 

 and overflows. The effect can probably be imitated with a long 

 water trough by momentarily opening and suddenly closing a trap- 

 door at one end. It can certainly be observed in a lavatory where 

 there is a constantly dribbling cistern for flushing purposes. By 

 opening and suddenly closing one of the wash-basin taps a surging 

 is set up in the connecting pipe, and the dribble becomes a periodic 

 for a second or two, in synchronism with the period of longitudinal 

 vibration of the water in the pipe. 



