J. Trowbridge — Side Discharge of Electricity. 59 



fluctuating feeble discharges took place to earth through E. 

 This phenomenon seems to indicate a discontinuity in the 

 stratified discharge. 



When the small spark gap, either at the positive or nega- 

 tive pole, is of a suitable length, the discharges between E and 

 either pole of the battery succeed each other so rapidly that 

 the side discharges to earth appear continuous. If a large con- 

 denser is substituted for the earth at E, one plate of the con- 

 denser being connected to earth, the time between each dis- 

 charge is lengthened. This time of charging can be well illus- 

 trated by connecting condensers directly through a large water 

 resistance directly to the poles of a large storage battery and 

 allowing the condensers to discharge through a spark gap. The 

 time of discharge can be regulated through a wide range and 

 the arrangement can be termed an electric clock. 



It is probable that in the case of lightning side discharges take 

 place to the earth in the manner indicated by this method ; the 

 potential between the positively and negatively charged clouds 

 rising to a higher value than that between the clouds ; the 

 earth space beneath the clouds acting as a localized capacity. 



