WWII U.S. Navy "Zig-Zag" Control Clock, circa 1940s and made by the Seth Thomas Clock Co. for the U.S. Navy.

WWII U.S. Navy "Zig-Zag" Control Clock, circa 1940s and made by the Seth Thomas Clock Co. for the U.S. Navy. With a luminous 12-hour black dial faces with Arabic numerals, seconds bit and fast-slow regulator at 12 o'clock, and spade hands. Marked on the dial U.S. NAVY / ZIG-ZAG CONTROL and at bottom Made by Seth Thomas in U.S.A.. Dial is 6" diameter. See Whitney, Maurice, Military Timepieces, p. 597 for text and examples. Zig-zag control timer clocks came into being in WWII with the purpose of providing convoys with a pre-selected steering program that would make it difficult for enemy submarines to "home" in on a ship's position and thus obtain a torpedo bearing. Condition report Normal usage wear. We do not guarantee working order of clocks and watches.