1126 
are then given by the appropriate intervals t, - ty and ty - ty. These 
are given in numerical form below as functions of ty for the experimental 
conditions used in this study, i.e., the op ee 4 = 25 ft, 
v=19 ft/millisec and c = 4.75 ft/millisec (v = 4c) have been made. 
Vea i 0.6580 - 0.2039 To + a [ =? + 156.25] # millisec 
for r,< R (16) 
t, - t, = 0 forr,>R (17) 
te-ty sty - t= 1216+ to - ty (18) 
The line representing Eq. (18) is plotted in os 6 ror curve ) 
and the observed break times corresponding to tr are shown to 
agree well with this simple calculation. The peak huge corresponding 
to to - ty, which might be expected to occur when r.< R = 48.4 ft, 
were, however, not distinguishable on all the records, since they 
usually occurred too close to the initial peak where the decay is 
extremely rapid. The points observed, however, agree well with the 
theoretical values (dash-dot curve of Fig. 6). The critical distance R 
is indicated by the short vertical dotted lines intersecting each curve 
at 48.4 ft. At distances greater than this critical distance the time 
differences are constant. 
D. Gauge Position C, in Bisecting Plane, Both Ends Detonated 
Simultaneously. From the symmetry with respect to the time of signals 
from x and @& - x, the time factors for this case can readily be 
derived as equivalent to those for the single-end initiation of a 
charge of length -6/2 with the gauge in a plane perpendicular to the 
charge axis through x = Ze/2. The expressions for t,, x; and tp are 
the same as given under c. The additional term req red, t La» is 
L % 
t b/2 Sa ees 0.6580 + 0.2105 tT (19) 
Break points are thus expected at 
EGe 
