( 23 ) 
disk with water. The bottom of the can had a grooved channel 
let into it and a spot of solder projecting above the center. After 
detonation, the beam was found ruptured and on its face there 
was an exact reproduction of the bottom of the can as seen in 
I'ig' J, which is a photostereotype. Evidently, here the material 
of the can has been projected into the iron beam. 
Fio. i. 
