In this experimental series, which was to clarify the possibilities of rescue from high altitudes, the experiments, simulating actual conditions, were carried out in such a way that rescue with parachute unfolded (designated as descending experiments) and with parachute folded (designated as falling experiments) were studied sometimes with and sometimes without oxygen breathing. Since the altitude or posture of the body is of essential significance for the demands made by the lack of O_{2} on the circulation, the experiments were carried out in sitting and prone positions; and, in descending experiments, in a suspended [page 3 of original] position in a parachute harness corresponding to the actual position. For purposes of demonstration certain of the experiments were recorded on film. Electrocardiograms were made of several experiments in the experimental series. Oxygen was breathed out of the customary low-pressure apparatus with continuous flow at altitudes over 10 km. [32,800 ft.]. The following experimental sequence was chosen: 1. Descending experiments without O_{2} breathing. 2. Descending experiments with O_{2} breathing. 3. Falling experiments without O_{2} breathing. 4. Falling experiments with O_{2} breathing. The sinking and falling times which were used in the experiments are tabulated in figures 1 and 2. [Figure 2 not reproduced.] III. Results of the Experiments _1. Sinking experiments without oxygen breathing_ Since a thoroughly dependable parachute oxygen apparatus is not yet generally available, experimental tests were made to determine from what altitudes a rescue with open parachute without oxygen is possible. Therefore, sinking experiments were carried out in which the mask was taken off after ascent with O_{2} (for speed of ascent of the chamber see fig. 1), and, after a waiting period of 10 seconds the sinking was begun. In the experiment no altitude sickness occurred at 9 km. [29,500 ft.] as was expected. In the sinking experiments, from 10 km. [32,800 ft.] altitude, typical altitude sickness occurred after about 2 minutes, i. e., at an altitude of about 8.6 km. [28,200 ft.], which was indicated by a very pronounced scrawling in the writing test. However, no loss of consciousness occurred. (Kloos’ writing test.) [page 7 of original]