288 The N.Z. Journal of Science and Technology. [Jan. 
The results obtained for the wires D-K are tabulated in Table I, 
together with values calculated from Parry’s formula. 
Table I. 
Wires. 
All Wires isolated. 
Others earthed. 
Observed 
Voltage. 
Calculated 
Observed 
Voltage. 
Voltage. 
Phase Angle. 
E-earth 
1140 
1182 
/217 0 17' 
620 
E-earth 
980 
1028 
/213° 16' 
355 
E-earth 
850 • 
847 
/207° 52' 
215 
G-earth 
750 
767 
/207° 24' 
195 
H-earth 
1120 
1153 
/211° 58' 
530 
K-earth 
850 
853 
/205° 41' 
255 
E-E 
130 
172 
/242° 10' 
E-E 
340 
373 
/239° 5' 
E-G 
430 
446 
/234° 25' 
E-H 
100 
112 
/289° 35' 
E-K 
370 
387 
/243° 35' 
E-F 
150 
202 
/236° 28' 
E-G 
250 
277 
/228° 10' 
E-H 
100 
127 
/21° 25' 
E-K 
190 
215 
/244° 45' 
E-G 
< 100 
80 
/212° 20' 
E-H 
300 
314 
/43° 5' 
E-K 
< 100 
33 
/306° 55' 
« • 
G-H 
390 
393 
/40° 55' 
s • 
G-K 
< 100 
89 
/10° 35' 
H-K 
300 
1 
319 
7229° 0' 
In the case of an isolated wire the agreement between theory and experi¬ 
ment is surprisingly close, and, considering the uncertainty of the influence 
of poles, &c., on the capacities of the wires, is much nearer than might be 
expected. 
The values with the neighbouring wires earthed will be seen to be much 
smaller than with all the wires isolated. This is due to the increase in 
capacity of the wire under observation owing to the presence of neighbouring 
earthed conductors, which all tend to lower its potential. Take the case 
of F, for example, for which the reduction is greatest. The values of K a 
from the calculations are 
M/ _ -*00546 
’ M a + C f~ *00546 - *0586 ’ 
from which it may be seen that if M f remains practically constant, C/, or 
the capacity of F to earth, is the determining factor. 
In general M f will be small, and in this case the voltage will be roughly 
in the inverse ratio to C f. 
From these general considerations a method of reducing the voltage 
of an isolated wire near a transmission-line is indicated—namely, to intro¬ 
duce additional capacity. 
