Fig. I. — X-Ray photograph (Coolidge) of two loaded cartridge cases. 



In the first the outer tube of cardboard is quite invisible ; in the second the case and powder show faintly. In 

 both the detonator in the base of the cartridge will be noticed. 



Fig. 2. — X-Ray photograph (Knox and Kaye) showing front and side views of a laminated 



wooden spar of an aeroplane. 



The spar is made up of three laminae glued together. The external appearance was excellent, but the radio- 

 graphs show that the middle layer contains two knots and a grub hole and should not have been used. 



[119 



