BOMBS AT BIKINI 



ference produced abnormally high readmgs.* Oddly 

 enough, one of the most valual^le of all the pressure 

 results was that obtained from a specially-mounted beer 

 can, whose graceless collapse filled an otherwise serious 

 gap in the pressure story. 



IMPULSE 



The measurement of impulse, although less satis- 

 factory than the measurement of pressure, was entirely 

 adequate. Despite the timing signal failure mentioned 

 previously, a number of good records of pressure-ver- 

 sus-time were obtained. From these, by the usual 

 method of integrating, physicists computed the impulse 

 values. As expected, the net impulse was practically nil 

 except extremely close to the Zeropoint. At greater 

 ranges the impulse delivered by the positive pressure 

 phase was almost exactly counterbalanced by the nega- 

 tive phase, which started one-half to one second later. 



But even though the net impulse was practically nil 

 at most of the target vessels, the net effect was far 

 from nil. It was, of course, the impulse during the posi- 

 tive phase which was responsible for the majority of 



^Although the homh detonated at approximately the planned 

 altitude, its plan-view position was 1500 to 2000 ft. to the ivest of 

 the intended hull's-eye ship NEVADA. How this discrepancy oc- 

 curred has been the subject of long study; but no answer has bee^i 

 found. Incontrovertible evidence is available to disprove each of the 

 dozen different hypotheses which may be advanced as explanation. 

 No discrepancy of anything like this magnitude occurred in the 

 long series of practice drops made. 



114 



