i04 
MESSRS. W. DE LA RUE AND H. W. MULLER ON THE 
by ebonite outer rings held by bolts which screw into half-rings at the back of the 
neck-shaped openings of the tube. This tube is numbered 199 ; the distance between 
the terminals, a ring, and a straight wire is 33'5 inches, 85 centims. Another tube. 
No. 200, 34 inches, 86'4 centims., long and If inch, 4‘4 centims., diameter, 30 inches. 
