Show glass Ornaments 9 save lives in war if you talk about prisms grandma might think you mean the glass ornaments decorating her chandelier but her grandson if hes a GI joe is aware of the fact that solid glass prisms have been the means of saving many lives during the war it was early in the war that the army wanted a tank periscope superior to the old style type made of I 1 mirrors and flat glass windows As a result glass technicians here developed a new plate glass prism that supplied about a 50 per cent increase in visibility and equally equall 1 i if f not more important this sl superiority diperi 0 yit y was achieved in a unit that could be mass produced to take care of the desperate need for prisms traditionally turned out in small quantities by the precise handicraft methods of the optical industry when the first U S tanks went into combat however a great need for prismatic viewing blocks developed in those first tanks commanders had to stand in the hatch exposed to sniper fire if they wanted a full view of their surroundings an alarming number were killed the answer was a new type of bullet resisting viewing panel developed by libbey owens ford glass company made of laminated plate glass the tank observation panels are so placed that tank crews and commanders are enabled to obtain a degree field of vision when in action without having to open the hatch to see going on the prismatic viewing blocks utilize for the first time the refractive properties of plate glass to obtain a some indication of the importance of these prisms might be gleaned from the number thus far turned out by the gla glass Ss concerti concern to date more than have been produced for various ins instruments trumen ts of war |