Show invisible light thwarts enemy ri J z fifa v y L i 11 paw V lo 10 go 1 73 A P n sy 0 sie r 1 r 0 y X 18 y 7 t ii f xi X y i sv w ff te mast Z i ix adequate street lighting even during blackouts black outs was assured i flo by the invention of so called invisible light by capt S j bi i aker officer upper left the signal gun throws a 1 marrow bf of light four miles the beam is invisible from a height 1 t of w m 80 yards and invisible to anyone on the ground anle unless S t that at bearn erson ore object intercepts the beam bottom left the type of light i tt to be evlan aih or all city corners right road lights spaced about 3 yards ards apar |