1122 
approximation, of the distance from charge to gauge. Figure 6 shows 
the comparison of observed durations with those calculated from 
Eq. (3) using the approximate velocities, v = 19 ft/millisec and 
ec = 4.75 ft/millisec. 
B. Gauge Position B, on Charge Axis, Away from Detonator. The 
first signal to arrive at gauge B is from the charge element at x = L 
i.e., the explosive farthest from the detonator. In this case, 
t, = Ly + r,/e (4) 
The final signal is from the charge element at x = 0, and 
tp = (2 + 3r,)/c (5) 
Thus the duration is 
te - t, = Li(lfe - 1/v) (6) 
Comparison with observed durations in this gauge orientation are also 
included in Fig. 6. 
It is interesting that the ratio of the durations at the two axial 
gauge orientations relative to the initiator end is independent of the 
charge length. 
duration near the detonator £ UNEtUO 2715 (7) 
duration away from the detonator voc 3 
C. Gauge Position C, in Charge-Bisecting Plane, One End Detonated. 
This case is considerably more complicated to treat than are the cases 
in which the gauges are on the charge axis. The principal difficulty 
arises from the fact that the initial signal to reach the gauge at 
time t; may come from a charge element, x,, at 05x, = 2/2, depending 
upon the distance ro of the gauge from the charge center. This is 
illustrated in Fig. 7. For convenience t, - t, is used in place of t, 
(the time of arrival of a signal from a charge element x ft from the 
detonator) to reduce the scale of the graph. "Break points", or points 
miles 
