Popular Science Monihly 



.5-21 



A Bazooka Is a Musical 

 Wimwam 



THINGS are not what 

 they seem. This ob- 

 servation of Longfellow's is 

 borne out by the mysteri- 

 ous looking instrument in 

 the hands of the soldier 

 boy in our picture. It 

 may look to you like a 

 cross between a plumber's 

 sign and an opium pipe or 

 almost anything else, but 

 it isn't. You will learn 

 the truth the next time 

 you visit a cantonment. 

 You will learn that this 

 queer-looking object is a 

 musical instrument christ- 

 ened the "Bazooka." How 

 does it sound? Just as it 

 looks. If you know any- 

 thing about plumbing or 

 steam-fitting you will at 

 least admire the bazooka as a good piece 

 of pipe-fitting. The rookies are exceed- 

 ingly proud of this weird noise-producer. 



Even in Turning a Corner the Brakes 

 on the Rear Wheel Take Hold 



IF you have miraculously escaped in- 

 jury in a skidding automobile on a 

 slippery pavement, 

 you can readily un- 

 derstand why the rear 

 wheels of a motor 

 truck semi-trailer 

 should have been pro- 

 vided long ago with 

 some form of brakes 

 controlled from the 

 driver's seat. In tact 



Yankee Doodle came to 

 town playing the Bazooka 



it IS quite as necessar- to 

 have brakes on the rear 

 wheels of a semi-trailer 

 as on an automobile, for 

 the reason chat the great- 

 est portion of the trailer 

 load is generally carried 

 on the rear wheels. This 

 causes them to swerve 

 around very easily when 

 the brakes are applied to 

 the driving wheels of the 

 tractor. 



One of the greatest dif- 

 ficulties in the develop- 

 ment of such brakes has 

 been the weaving and 

 twisting strains set up be- 

 tween the tractor and the 

 trailer and the necessity 

 of making the brakes hold 

 when the trailer swings 

 around at an angle to the 

 tractor centerline as in 

 turning corners. 

 This difficulty has been overcome in 

 the new type of brakes, shown in the ac- 

 companying illustrations, by mounting 

 the front end of the brake rod in a uni- 

 versal joint at the center of the fifth- 

 wheel, which supports the front end of 

 the trailer body on the tractor platform. 

 As a result, the brakes, which are of the 

 conventional motor-truck type, are always 

 operative, whether the 

 trailer is moving up and 

 down, as when running 

 over rough roads, or 

 v.hen turned, as in 

 rounding corners. The 

 brakes are set and re- 

 leased by an ordinary 

 brake-handle operated 

 from the driver's cab. 



The illustration shows regular motor-truck brakes applied to a semi-trailer and 

 operated through a universal joint so that they may be used on corners' and turns 



