510 



Popular Science Monthly 



visibly and to drop vertically. The up- 

 permost one is seen gliding like an air- 

 plane itself in spite of its great weight, 

 in spite of its comparatively small surface 

 and in spite of the fact that it has only a 

 belly in place of wings. The moment 

 bombs drop from their tubes (one-third as 

 slowly as they are swept ahead by the 

 plane) they are swung by momentum and 

 air pressure on 

 their tail planes 

 into a nearly 

 horizontal po- 

 sition. In that 

 position their 

 shape encoun- 

 ters practically 

 no resistance 

 from ahead 

 but a great re- 

 sistance in the 

 direction of 

 gravity, not 

 only because in 

 trying to fall 

 they must 

 cleave the air 

 with their big 

 broad sides, 

 but chiefly be- 

 cause in drop- 

 ping they are 

 now opposed by 

 the inertia of 

 the air encoun- 

 tered in falling, 

 and, in addi- 

 tion, the much 

 greater amount 

 of air encoun- 

 tered in mov- 

 ing ahead. As 

 long as momentum continues, falling is 

 greatly retarded, and, with practically no 

 head resistance, it is bound to continue 

 indefinitely. But as soon as actual falling 

 begins, the head dips a little, aided by the 

 tail planes. In this position the fall itself 

 will preserve and increase the horizontal 

 speed, just as in coasting down hill in a 

 sleigh. If the total surface of a correctly 

 designed bomb were not so extremely 

 small in proportion to its weight, it 

 would seemingly never reach the ground. 

 Balloonists sometimes threw empty 

 bottles from their baskets. They mar- 

 velled at the crazy antics performed by 



Slipping a bomb into an airplane. The tail is 

 being inserted smoothly into the discharge tube 



the bottles and the long time they took 

 in reaching the ground. It was the ap- 

 proximation of streamline form that de- 

 layed the bottles. 



Bombing is like torpedoing. Bombs 

 have assumed the shape of torpedoes 

 not to prolong their fall, a thing in it- 

 self rather unfavorable, but because the 

 lower winds have practically no influence 



over a torpedo. 

 Guided by its 

 tail, the tor- 

 pedo-shaped 

 bomb simply 

 turns its sharp 

 nose against 

 the wind and 

 cleaves it 

 without deflec- 

 tion. 



That is why 

 bomb-drop- 

 ping is more 

 accurate than 

 it was at the 

 outbreak of the 

 war. More- 

 over, bombs are 

 dropped on the 

 shotgun or 

 blunderbuss 

 principle. In 

 other words, 

 they are re- 

 leased a half a 

 dozen or more 

 at a time. One 

 at least will 

 find its mark. 

 By releasing 

 bombs in quick 

 succession. 



errors in judging altitude and speed are 

 readily corrected, because the bombs 

 scatter principally along a line parallel 

 with the path of the machine. 



y\re You Afraid to Look at Yourself 

 in a Mirror? 



Dr. Martiri has recently found that 

 certain patients are afraid of mirrors, 



a result of watching the change in 

 appearance as emaciation progresses. 

 When a dyspeptic is cured his horror of 

 looking in a mirror persists. This is 

 called cattotrt)phobia. 



