192 
MESSRS. W. DE LA RUE AND H. W. MULLER ON THE 
reminding one of 102, fig. 46, which shows a phase of tube No. 129 at 11 -5 
m.m., 15,132 M. 
116. — Pressure 10 m.m., 13,158 M, 8040 cells. The luminosity assumed the 
form 4, fig. 50, closely resembling tube 129 at 10T m.m., 13,289 M, the 
left of 104, fig. 46. 
117. — Pressure 9 '04 m.m., 11,895 M, 8040 cells, C. 0’01412 W. Two luminosities 
as 5, fig. 50, recalling tube 129, at a pressure of 9T m.m., 11,974 M, 107, 
fig. 46, but in the latter the arrow-headed precedes the other luminosity. 
Fig. 50. 
118. — Pressure 6'319 m.m., 8314 M, 8040 cells. Three arrow-headed luminosities 
as depicted in fig. 3, Plate 15, copied from a photograph and a drawing 
made at the time. The photograph was obtained in 2 seconds. 
119. — Pressure 4T m.m., 5395 M, 6960 cells, C. 0’0232 W. The luminosities as 
depicted in 7, fig. 50 ; the first near the negative having a peculiar flat- 
hat-like form, behind which are some strata convex towards the positive. 
120. — The exhaustion was continued, but no regular strata could be obtained 
until the pressure bad fallen to 0'823 m.m., 1082 M, when with 2400 cells 
strata, twelve in number, like the first on the left in 21, fig. 50, were pro- 
duced, the rest of the discharge towards the positive being confused. 
121. — Pressure 0'518 m.m., 682 M, 2400 cells. Nineteen saucer-shaped strata 
were formed, and from time to time fainter strata flashed in between them, 
the phenomena resembling fig. 5, Plate 16. 
