miles which would give a definite number of complete laps and
a fraction of the next lap. By adding a number of laps in this
way, curves can be plotted showing the actual distribution of
voltage and current over the line at any given instant; or values
of current and voltage at a given point of the line can be found for
successive instants and from this data curves can be plotted



Digitized by VjOOQIC



ELECTRIC OSCILLATIONS AND ELECTRIC WAVES. 219

showing voltage or current at any point as functions of elapsed
times. The ampere-time curves in the lower parts of Figs. 153,
154 and 155, and in Figs. 156 and 157 were obtained in this way.
emrpei^ dmrmTgnwih ti B aav^of emrr^ gmwik ^ B



Fig, 155.
Same as Fig. 153 except that distant end of line is connected to a non-inductive

circuit of which the resistance is R » 3 'J-, In this case the ribbon wave is only

partiaUy reflected from the end R and the successive laps of the ribbon wave are
thereby greatly reduced in intensity as represented by the shading.
Note. — ^The character of the reflection at B in Figs. 153, 154
and 155 is determined by the condition that the sum of the vol-



Digitized by VjOOQIC



220



ADVANCED ELECTRICITY AND MAGNETISM.
tages in the successive laps must always be equal to battery
voltage E, and of course there is always an odd number of
laps at B, one, or three, or five, etc.
a«li«f f



axUfff time



asdicf t



r^



JsSB^BL^BBBLm



Fig. 156.
Showing growth of current at B



in



Fig. 157.
Showing growth of current at K in



Fig. 155 when ^^l^j^



Fig. 155 when R^^J-.
