Since the Bárány chair has been universally used by both the Army and Navy in the selection of candidates for aviation, we thought it desirable to see if there really is any correlation between flying ability and the Bárány tests. We knew, for instance, that trapeze performers and Russian dancers have very little, if any, nystagmus after whirling, and yet their proficiency in their professions depends on their sense of balance. We knew that men who have a so-called "normal" nystagmus time before flying often lose all or a great part of it after numerous flights. It seemed to us, therefore, that for the most part the use of the chair has been taken more or less on faith after the following line of reasoning: A well defined sense of equilibrium is necessary for aviation. The Bárány chair determines the normality or abnormality of function of one's semicircular canals, which