World War II era Hamilton Navigator's chronograph watch, Model 23, housed in an original U.S. Army metal canister carrying case with round viewing window, manufactured by George H. Adamson, of Tecumseh, Michigan. Circa 1942-1943. This watch was used by the U.S. Army Air Corps as a navigation watch and bomb timer. It comes in its protective metal canister with spring cushion support mechanism. These cases are rarely found and were given to the navigators of various types of bombers and troop carrier planes, so that they could synchronize the timing of their missions. The Hamilton Model 23 has a 16 size Keystone base metal case bearing the serial number 574342. It has a complex, high grade movement with 19 jewels, 1/5 split second divisions on the black dial, suspended and compensated balance, stem wind/stem set, single button start/stop/reset chronograph/timer. Easy to read white Arabic numerals and hands on a black dial, with dual subsidiary 60 seconds dial and 30 minutes counter. Movement, serial number P17423, adjusted to temperature and 3 positions. Condition: excellent dial; one small scratch to bezel; as found, but running and fully functional; some scratches to exterior of Keystone watch case where it snaps into the canister suspension. No military contract markings on the back of the watch case. Metal canister in very good original condition with manufacturer's metal label affixed.