A recent review article1 has pointed out the paucity of quantitative data on which valid comparisons may be made of various technics for performing artificial respiration. At present the two most widely discussed methods are the Schafer prone pressure and the Eve tilting2 or gravity technics; the former is recommended by the American Red Cross, while the latter is used extensively by the British navy. In view of the prolonged and often bitter controversies in the field of artificial respiration, it is interesting to note that the relative effectiveness of these two methods has been measured in only 3 subjects who might possibly be considered to be in need of artificial respiration. Each of these 3 was anesthetized deeply with ether, then rendered apneic by passive hyperventilation and immediately subjected to the Schafer and Eve technics while measurements of tidal air were made.3 Data on these patients