DISCOVERY 



285 



air even though it may be rising in relation to the 

 ground under the influence of an up-current of wind. 

 That is why the selection of the site is so important 

 for gliding experiments ; because the duration of the 

 glide may, by a skilful pilot, be prolonged by taking 

 advantage of the up-currents which are to be met 

 with on the windward side of hillocks or small inequali- 

 ties in the groxmd with the wind in certain directions. 

 In the Wasserkuppe region in Germany, where such 

 remarkable results have been achieved, the groimd 

 towards the south falls away rapidly in a smooth 

 slope which is admirable for simple glides. But it is 

 on the west that it is most favourable for spectacular 

 performances, though even there only when tlif 

 direction of the wind is also from the west. This 

 enables the glider to get into an up-current immedi- 

 ately on leaving the ground, through which he can 

 gain sufficient height to enable him to circle and make 

 for a series of low hills at the foot of the main slope, 

 which each possesses characteristic wind eddies and 

 currents which can be turned to advantage. As a result 

 of a careful study of these local currents over many 

 years — this country was first used for gliding in 1912 — 

 the German expert gliders are enabled to put up per- 

 formances which could only be equalled elsewhere 

 after prolonged study of local meteorological conditions. 



True " soaring " flight, if such be possible, does not 

 appear yet to have been achieved in the sense in which 

 birds are said to soar : by which is meant effortless 

 horizontal flight under conditions where no up-current 

 — whether arising from configuration of the ground or 

 from the heating of the air by the sun's rays — appears 

 to exist. Various theories have at different times 

 been advanced for this phenomenon, the most probable 

 of which is that, even in an apparently steady horizontal 

 wind blowing over the surface of a perfectly flat plain, 

 there are regular or irregular pulsations, the vertical 

 component of which a bird is able to turn to account 

 by minute adjustments of the angle of its wings. An 

 attempt is being made to test this theory in certain 

 special gliders which have recently been buUt in 

 Germany. The rear edges of the wings are free to 

 move up and down against helical springs, which it is 

 hoped will enable them to adjust themselves rapidly 

 to these supposed pulsations, and so take advantage 

 of their effects. Whether or not this will be successful 

 remains to be seen, but to a student of the past it 

 seems strangely reminiscent of Octave Chanute's 

 system for maintaining longitudinal equilibrium, and 

 one cannot help feeling that, after allowing for all the 

 aerodynamical development that has taken place in 

 the meantime, there must be more in it than that or 

 he would have discovered it. 



It is, as has already been hinted, impossible, in the 

 writer's opinion, yet to say whether or not gliding has 



a utility as a means of scientific observation midway 

 between the laboratory and the full-scale aeroplane. 

 The chain between the two is admittedly not yet com- 

 plete, but the facilities for observation in a glider would 

 appear to be limited, as the operator is fully occupied 

 with the maintenance of his position in the air. This 

 difficulty might, it may be said, be overcome by carry- 

 ing a passenger to do the observing, but he would not 

 have the intimate " feel " of the machine that the 

 pilot has. On the other hand, the weight of the 

 necessary recording instruments for taking mechanical 

 observations of the phenomena would be very con- 

 siderable and likely to be prohibitive. 



Whether or no the glider proves a scientific instru- 

 ment, it certainly provides a cheap and attractive 

 way of gaining a knowledge of the air ; with the 

 proviso that extrication cannot be made from a 

 difficult position by switching on the engine, as in an 

 aeroplane, and the most dangerous situations aie 

 likely to occur where there is little or no air-space 

 below in which to recover. 



The Fear of Death 



By F. A. Hampton, M.B., M.C. 



The average man is wisely too preoccupied with life 

 to be much concerned with the idea of death ; in fact 

 it may be doubted whether the idea of death as such 

 plays any significant part in the life of the normal 

 individual, for it would seem to be very difficult for 

 man to form a subjective idea of death, that is, to 

 imagine himself either as having ceased to exist or 

 (the slightly easier alternative) as existing in some 

 fashion outside his material surroundings. If we 

 assume that the mind was evolved not in order to 

 enable man to think, but to enable him to act more 

 efficiently, then it is not surprising that it should 

 prove inadequate to so sterile and useless an activity. 



A situation that threatens life, or the anticipation 

 of such a situation, may fill us with fear, and it is well 

 for our self-protection that it should do so ; but if 

 we examine this fear it is rare to find that it contains 

 any conception of death, and we can hardly say that 

 a distinct fear of death stands out from the general 

 protective emotion of fear evoked by any circum- 

 stance that threatens injury or destruction. 



The late war provided situations enough of this 

 kind, and if we inquire into the feelings of those who 

 were exposed to them, we find that the fear was 

 rather of the immediate physical violence than of its 



