ELECTRIC DISCHARGE WITH THE CHLORIDE OF SILVER BATTERY. 507 
The dimensions of the tube are:—Length, 15'5 inches (39'3 centims.), and 
175 inches (4*44 centims.) in diameter, and the distance between the terminals, a 
point and a ring, 12 inches (30'5 centims). 
A battery of 3600 cells was used, the terminal, in the shape of a point, was con¬ 
nected to the positive pole, and the ring and negative pole of the battery were both 
connected to earth. The gas used was carbonic anhydride. The full potential of the 
battery was found to be 313 divisions of the electrometer, that of the idle axial wire 
at a certain exhaust 142 divisions, equal to 1633 cells. 
Fig. 28. 
The exhaust was carried further, and it then required 6000 cells to produce a 
discharge. The tube potential was found to be equal to 2523 cells, and the idle 
wire, T, 2535 cells, or practically the same as the tube. 
Another set of experiments was made with the same tube, and progressively 
greater and greater exhausts, consequently presenting different appearances of the 
luminosity at the negative ring as the exhaust was increased. These appearances are 
shown in fig. 28, Nos. 1, 2, 3, 4, 5, in which the idle wire, T, is connected with the 
electrometer. 
