During World War I research and development of the first U.S. military parachute was underway at McCook Field, Ohio. To test the parachute, engineers experimented with several types of dummies, settling on a model constructed of three-inch hemp rope and sandbags with the approximate proportions of a medium-sized man.[30] The new invention was soon known by the nickname “Dummy Joe.” Dummy Joe is said to have made more than five thousand “jumps” between 1918 and 1924.[31] By 1924, parachutes were required on military aircraft with their serviceability tested by dummies dropped from aircraft.[32] For this routine testing, several types of dummies were used. The most common type is shown in figures 17 and 18. Parachutes were individually drop-tested from aircraft until the early stages of World War II, when, due both to increased reliability and large numbers of parachutes in service, this routine practice was discontinued. Nonetheless, test dummies were still used frequently by the Parachute Branch of Air Materiel Command (AMC) at Wright Field, Ohio, to test new parachute designs. [Illustration: Fig. 16. “‘Dummy Joe,’ the hero of five thousand jumps” is shown here with engineers J.J. Higgins (_left_) and Guy Ball at McCook Field, Ohio in 1920. (_U.S. Air Force photo_)] [Illustration: Fig. 17. (_Left_) Early rope and sandbag dummy used to test parachutes. (_U.S. Air Force photo_)] [Illustration: Fig. 18. (_Right_) Parachute drop dummies in use at Wright Field, Ohio. The historic Flight Test hangars, Hangars 1 and 9, can be seen in the background. (_U.S. Air Force photo_)] Anthropomorphic Dummies The ejection seat had been developed and used successfully by the German Luftwaffe during the latter stages of World War II. The utility of this invention was realized when the U.S. Army Air Forces obtained an ejection seat in 1944.[33] To properly test the ejection seat, the Army Air Forces required a dummy that had the same center of gravity and weight distribution as a human, characteristics that parachute drop dummies did not possess. In 1944, the USAAF Air Materiel Command contracted with the Ted Smith Company of Upper Darby, Pa. to design and manufacture the first dummy intended to accurately represent a human.[34] The dummy had the same basic shape as a human, but with only abstract human features, and “skin” made of canvas. [Illustration: Figs. 19 & 20. (_Left & Right_) These early anthropomorphic dummies, manufactured by the Ted Smith Co., of Upper Darby, Pa., were used by the Army Air Forces beginning in 1944. They were replaced by a more realistic dummy in 1949. (_Right_) “Oscar Eightball,” the name given to this early model anthropomorphic dummy by Col. John P. Stapp, is shown following a run of the high-speed track at Muroc AAF (now Edwards AFB), Calif., in 1947. (_U.S. Air Force photos_)]