696 



Popular Science Monthly 



You Can Rock This Boat but You 

 Can't Turn It Over or Sink It 



THE several hull sections of the collaps- 

 ible boat illustrated are tapered so 

 that they telescope. Packing rings between 

 the joints prevent leakage. The sections 

 are distended by pressure on three 

 tubes and then locked. 

 To prevent tilting 

 boat the 

 inventor, 

 Yves And- 

 re Bouget, 

 "of Philadel- 

 phia; has ' 

 attached to 

 the hull of the boat 

 stabilizing casings 

 or shells. These 

 shells have remov- 

 able plugs in their 

 tops, but ordinarily 

 the tops are closed 

 and the bottoms 

 opened to admit 

 water. 



A rod and transverse bar lock the hull 

 sections after they have been distended 



A New Twelve-Cylinder Aeroplane 

 Engine Makes Its Debut 



THE aeroplane engine is the lightest 

 motor made, for the power it gives. 

 Although its use in driving the propeller 

 of an aeroplane is well established by this 

 time, it is now attracting the attention of 

 automobile owners. At least one car 

 owner in the United States has a twelve- 

 cylinder aeroplane engine 

 under his motor hood. The 

 illustration at right shows a new 

 type of aeroplane engine 

 mounted for testing purposes on a 

 motor truck. The engine turned the 

 propeller fast enough to move the truck 

 through the snow. 



While the engine operates at more 

 than two thousand revolutions per 

 minute, the propeller is geared down to 

 give a rotation of from looo to 1400 per 

 minute. The arch enemy of lightweight 

 motors is vibration. In the new motor 

 vibration has been avoided. Every 

 moving part is held secure and rigid. 

 The camshaft is located next to the 

 valves, situated on top of the cylinders, 

 and with the rocker arms is enclosed 

 in an oilbearing casing, thus granting it 

 the same benefit that the crankshaft and 

 connecting rods have from their casing. 



Through an oil-tight joint the other ends 

 of the rocker arms stick out into the 

 open where the valve springs are best 

 protected from heat. Every three of the 

 twelve cylinders form a solid block, within 

 which nothing can shake loose. The 

 crankshaft is stout and short, owing 

 to this "twin-six," V-shaped 

 arrangement and to the con- 

 necting rod having forked 

 wrists. 



Lubrication by 

 power (forced feed) 

 insures an ample 

 supply of oil. There 

 is an angle of only 

 forty degrees be- 

 tween the two sets 

 of cylin- 

 ders, thus 

 insuring 

 compact- 

 ness and elim- 

 inating vibration. The 

 cooling waterjackets 

 are made extra long. 

 The pistons have three 

 rings to utilize every 

 fraction of pressure. An electric starter 

 makes it unnecessary to crank the motor 

 by turning the propeller by hand, and 

 gives full power control in the air. The 

 motor furnishes two hundred horsepower. 

 Yet the individual cylinders are only 

 four by six inches, and a block of three 

 weighs only forty pounds. 



The truck was driven through heavy snow 

 by the aeroplane motor and the propeller 



