76 Mr. W. Spottiswoode on Stratified Discharges. [May 18, 



tion of striae prevails througliout the entire discharge. The striae which 

 fill the main part o£ the field present a proper motion nearly uniform, 

 but slightly diminishing towards the end. These striae are for the most 

 part unbroken, but are occasionally interrupted at apparently irregular 

 intervals. When the battery-surface is increased the elementary striae 

 are more- broken, and near the head of the column the interruptions 

 occur as in the figure. The separation of the earlier part of the dis- 

 charged into striated columns divided by intervening rifts does not, 

 with the exception of the first, extend far towards the positive terminal. 

 Nevertheless, even as far as the positive terminal itself, there seems at 

 times to be a fuller development of discharge than is subsequently main- 

 tained. 



The first rift in the discharge, following the first outburst, is some- 

 times distinguishable even as far as the positive terminal ; and perhaps 

 in those cases indicates a real cessation of the discharge. This is corro- 

 borated by the fact that a similar interruption is then perceptible in the 

 glow surrounding the negative terminal; but after this the negative 



