ELECTRICAL WAVES AND SOME OF ITS APPLICATIONS. 
5 
the deflection was the same as before. When this is the case the ratio of the 
maximum values of the first and second half oscillation is given by the ratios of the 
arcs traversed by the di.scharge. 
In this way the rate of decay of oscillations in ordinary discharge circuits was 
examined. With short air breaks and copper wires for connection, it was found that 
the damping was hardly appreciable. As the length of the spark gap was increased, 
the absorption of energy in the air-break caused the oscillations to damp rapidly. 
If the copper wires of the discharge circuit were replaced by iron wires, there was 
in all cases a very rapid decay of the oscillations, whatever the length of the air- 
break. If an iron cylinder were placed in a solenoid, the absorption of energy by the 
cylinder caused a rapid damping, while a copper cylinder of the same diameter had 
no appreciable effect. 
Experiments on Damping of Oscillations. Discharge circuit rectangular, 184 centims. 
by 90 centims, ; Self inductance of circuit, L = 7,400 ; Capacity, 0 = 2,000 
electrostatic units ; Frequency, 1‘25 millions per second. 
Length of spark 
gap. 
Eatio of amplitudes 
of two first half 
oscillations. 
Itesistanco. 
cectim. 
ohms. 
•06 
•98 
— 
•12 
•97 
11 
•24 
•93 
2-6 
•37 
•9 
3-7 
•49 
•79 
8-4 
•61 
•7 
12-4 
In the third column the apparent resistance, corresponding to the absorption of 
