710 



Popular Science Monthly 



peded has had its influence on naval archi- 

 tecture. Who can forget the warships of 

 twenty-five years ago, bulging masses of 

 sponsons as they were? All these eccentric 

 curves, which almost con- 

 cealed the true lines of the 

 hull, were intended to 

 increase the firing efficiency 

 of the guns. 



The Gotha marks a 

 similar step in the evolu- 

 tion of the airplane. Be- 

 cause of the difficulty of 

 mounting guns on a flying 

 machine, odd shapes are 

 beginning to appear in 

 the air. The need for an 

 inverted channel through 

 which a three-inch rapid- 

 fire gun could fire with 

 ease was most imperative 

 in the two-motored 

 Gotha bombing machine, 

 relatively the slowest of 

 all German airplanes. 

 Such a craft is likely to 

 be called upon to engage 

 in a running fight. Fir- 

 ing to the rear is not a 

 new idea itself; but it has 

 always been done over 

 the top of the fuselage 

 from the cockpit. There 

 was left below the fuse- 

 lage an immense dead 

 angle in which a pursuing machine might 

 securely attack. 



No doubt the Gotha's tunneled tail 

 will be imitated by the Allies; for their 

 big bombing planes are even larger and 

 slower than the Gotha. The number of 

 guns that an air plane can carry are 

 so limited by considerations of weight, 

 that each must necessarily be so 

 mounted as to secure the maximum 

 efficiency. This is the point on 

 which the Gotha shows its superi- 

 ority. 



By the adoption of a similar firing 

 tunnel or vault for Zeppelins it is 

 possible that the giant rigid dirigible 

 which has dropped so low, recently, 

 in the estimation of the German au- 

 thorities, may be restored to military 

 favor despite its vastly greater bulk 

 and vulnerability when pitted against 

 fast, elusive, fighting airplanes of later 

 date, firing inflammatory bullets 

 from machine guns. 



Trousered Legs Are Not Always 

 What They Seem 



HERE is a boon for the bow-legged man. 

 It is a light, flexible structure which 

 can be strapped around the leg above the 

 knee to preserve the straight line of the 

 trouser leg. The strap would take the 

 place of his garter, the lower end of the 

 brace device being fastened to the sock 

 with an ordinary garter- 

 clasp. To the con- 

 necting strap a number of 

 short lead struts are 

 hinged. These are held 

 projecting outward more 

 or less horizontally from 

 the leg. By adjusting the 

 slope of these struts, the 

 distance of the outer strap 

 from the leg can be ad- 

 justed at the different 

 points and this regulates 

 the "bulge." The struts 

 " give" sufficiently to 

 prevent discomfort. 



**S» 



Two straps held apart by adjust- 

 able metal struts keep the outline 

 of the trouser leg always straight 



Sidewalks Flushed 



Without Disturbing 



Parked Cars 



CHICAGO has discov- 

 ered a way to flush 

 her sidewalks without dis- 

 turbing the automobiles 

 and other vehicles which are parked along 

 the curbing. Two automobile tank trucks 

 are used to clean the downtown section of 

 the city every night through a pipe ex- 

 tention to the discharge line as shown 

 in the photograph below. 



Flushing the sidewalk from an overhead pipe 

 leading from the tank truck in the street 



