732 Prof. A. S. Eve on Changes in Velocity in an 
Fig. 4. 
Secondary fays 
115 
no 
too 
35 
90 
85 
80 
Table III. 
Substance. 
Density. 
Secondary 
Radiation. 
Difference per cent, for 
A. 
±34,000 
Volts. 
±50,000 
volts. 
Lead 
114 
7-8 
2-6 
2-2 
0-9 
113 
95 
80 
79 
65 
165 
24-6 
35-8 
340 
41-0 
24 
36 
48 
28-3 
42 
50-0 
Iron 
Aluminium ... 
Brick 
Paraffin 
