Popular Science Monthly 



581 



undergone several simple cx;uninations, 

 tlie candidale is seated in a cliair and 

 the fnial, supreme test is ajiplied. 



How would most men act if a revolver 

 were discharged unexpected!)' behind 

 their ears? The answer is simiiie. The\' 

 would leap into the air; their heart-beat 

 would probably double; the\' would 

 gasp and tremble as if they had palsy. 

 In so doing they would promptly 

 disqualify themselves as aviators in the 

 French army. 



In testing the possibilities of an avia- 

 tor, various contrivances are attached to 

 the body, all having a definite purpose. 



Tubes lead from these devices to a 

 slowly rotating cylinder, on which i)aper 

 is wrappeil. They terminate in points 

 which record the slightest variations in 

 his [)h>sir|ue. 



When the clockwork has started and 

 he is perhaps wondering what the queer 

 apparatus is all about, a deafening ex- 

 plosion takes place a foot behind him. 

 The record made at that moment on the 

 revolving paper determines whether or 

 not he is to become a French war-aviator. 

 If his heart-beat, his respiration and his 

 arm nerv^es and muscles show no undue 

 excitement on the paper cylinder, he 

 goes to work. But if the stylus actuated 

 by his pulse -beat dances about the 

 rotating sheet, he is disqualified. It is 

 only natural that his reflex nervous 

 system should respond in some way to 

 this sudden stimulus; but the man who 

 tests him knows how wide a variation 

 from normal may be tolerated. 



Next in importance to the revolver- 

 shot test is that which ascertains the 

 candidate's promptness in acting upon 

 an external command. For example, 

 he is told to press an electric button 

 when he feels a light 

 touch on his left ear- 

 lobe, or when he sees 

 a light flash. His 

 ciuickness in acting 

 upon these sensations 

 determines whether or 

 not he could meet the 

 sudden contingencies 

 which occur in the air. 

 In a word, whether or 

 not he could handle 

 his 'plane over a roar- 

 ing battlefield with- 

 out losing 

 any part of 

 his nerve. 



The d'Arsonval chronormtt i . im h records on a smoked paper cylinder the pulse-beats, 

 respiration and nervous tremors of the applicant when a pistol is fired behind him 



