Besearches on Modern Explosives. 



227 



It is also noticeable that the thinner the couple the sooner is the 

 maximum point reached, i.e.^ the steeper is the curve and the sharper 

 its point, while with a thicker couple the point is more rounded, and 

 the maximum more slowly reached. 



Fig. 4 shows photographs of five results, two with a thick, and three 

 with a very thin couple. 



Fig. 4. 



Many difficulties were encountered in carrying out these researches 

 in order to secure reasonable accuracy in the work. Several hundred 



