1435 
In addition to these data, Table 1 gives the compressi- 
bility of the medium behind the shockwave. This compressibility 
was derived from the tables presented in Ref. 3 for the differ- 
ent conditions given by 7 % and v in each line of Table l. 
The last column of Table 1 gives the value of speed of sound in 
the medium behind the shockwave; this velocity was calculated by 
using the derived data for ay and v for jeach shock pressure. 
All these data for D, a, and u are plotted in Fig. l 
as functions of the amplitude of the shockwave. The approximation 
formulas (2), (4), and (5) are plotted as broken lines. This 
diagram proves that the agreement between the approximations and 
the exact data is good for pressures up to 500 at. 
