SOUL MACHINE.

Sun (Christchurch), Volume III, Issue 828, 5 October 1916, Page 6

SOUL MACHINE.

AIRMEN'S TEST. A REMARKABLE ARTICLE. One of the secrets of the superiority of the French flying man over his German antagonist, quite apart from the super-excellence of the French machine, is disclosed by M. Jacques Boyer in a remarkable article which he contributes to the "Scientific American'' on the method of examination of would-be "Navarres of the air." What are the mental-physical qualifications necessary in a prospective aerial pilot"? How are these to he defined and measured scientifically? This, says M. Boyer, is the delicate problem set themselves by Drs Camus and Nepper, charged with the testing and selection of candidates for the French aviation corps. Measuring Shock. The two doctors begin by measuring with the d'Arsonval chronoscope the time of psycho-motive reactions of the candidate.

Suppose, for instance, that an aviation pilot suddenly discovers! a machine gun, which had been concealed from him up to that; instant by the topographical features of the ground beneath him;! how much lime will he consume in the execution of a manoeuvre for the purpose of avoiding its fire? If, again, a violent wind threatens the destruction of his machine, how many seconds are necessary for him to put into operation the lever which; will assure his retreat from the atmospheric danger zone? The d'Arsonval chronoscope is employed in answering these questions. | In its essential features it consists; of a clock dial divided into 100 parts, 1 with a single hand. An electric cir-j cuit is so connected with the move-! ment of this clock, by means of a steel spring, that while the circuit is broken the mechanism moves the hand at the constant norma! velocity of one complete revolution per second, whereas the instant the circuit is made the spring contracts;' (under magnetic influence) and pulls l the wheels out of gear, halting thej] hand instantaneously. To measure the time of reaction of ii

an ordinary stimulus, the observer seats himself before the candidate, holding in his hand a tiny hammer. By striking this hammer sharply against the table he at once gives the stimulus to which the candidate is to react, and breaks the circuit by means of an electro-magnetic device connected witli the hammer. The candidate holds in his hand a small metallic pincher. Immediately on perception of the sound lie squeezes this together, thereby making the circuit again. The length of the interval during which the circuit was broken, representing the time of the subject's reaction, is read off from the dial by noting how far the hand moved while the circuit was open. After the candidate has been hitch-; ed up to all these instruments, a re-! volver is unexpectedly fired close to his ear, or a wet cloth suddenly applied to the back of his neck, and the effects of this treatment on his several functions under observation are read off from the graph.

Hand Fatigue. Further tests arc designed to meas-j ure the degree of loeal fatigue induced by extensive strain on the! hands and arms, and in particular by! the long con I i nued compression of! the hands demanded of the aviation I pilot. A special instrument is cm-! ployed in testing the endurance of ( the candidate's lingers. His arm and hand are so confined that only the one finger being tested can possibly; do any effective work. To this tin-! ger is attached, by means of a-cord; running over a pulley, a scale pan' with iron weights in it. A tooth gear furnished with a brake makes it possible for the candidate to raise this pan by contracting his linger,! but prevents the pan from going down again when the linger is relaxed. This is necessary to obviate' the fatiguing factor of shock from the descending pan, which could not he intelligently estimated. The candidate works his linger back and forth till it is incapable of further' movement, whereon the total weight of the pan is multiplied by the distance he has lifted it to obtain an index of fatigue for the finger in question.

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