Popular Science Monthly 



89 



and rear sets of wheels by means of a short 

 driveshaft. The power is in turn trans- 

 mitted through the gearbox by means of a 

 silent chain drive to two shafts, one extend- 

 ing forward from the front of the gearbox 

 and the other aft from the rear side. Each 

 of these shafts 



PNEUMATIC TIRES 

 AXLE™" 



two 

 gears, 



carries 

 worm 



these meshing 

 with large worm 

 wheels and dif- 

 ferentials 

 mounted on 

 supplementary 

 axles which 

 simply drive 

 each pair of op- 

 posite wheels, 

 but do not sup- 

 port any of the 

 wheel load. Each 



the center. The separate lever serves to 

 turn the vertical turn-bolt as the driver 

 turns his hand-wheel to steer. Additional 

 rods attached to one end of the two-armed 

 bar lead to the front set of wheels, and 

 other rods attached to the opposite end 

 lead to each op- 

 t " 



UNIVERSAL JOINTS 



SPINDLE ARMS EXTENDED MOTOR SHAFT MOTOR OFF CENTRE 

 Diagram showing the driving and steering arrangement 

 of the eight-wheel truck. All wheels turn for steering 



posite pair of 

 the rear wheels. 

 Thus as the 

 turn-bolt is re- 

 volved, causing 

 the two-armed 

 bar to revolve 

 about its pivot, 

 it makes the 

 front truck 

 wheels turn in 

 one direction 

 and the rear 

 wheels, con- 

 of the supplementary trolled from the opposite end, in the re- 

 driving axles is divided into two parts on verse direction, thus giving a very short 



each side, these parts being joined by means turning radius. 



of universal joints so as to permit relative 



motion between any of the wheels of each 



truck, as when passing over road obstruc- 

 tions, without binding any of the driving 



members. 



The motor must be placed rather 



high so as to clearthe front 



of the front truck. The top 



the motor extends up into th 



driver's cab and is covered 



by a removable metal hood 



The driver sits on one 



side of the motor and the 



helper on the other. This 



construction permits the 



driver's seat to be placed 



well forward, which in 



turn allows a longer 



body on the same 



length of chassis than 



would be the case in 



the usual construction 



with the motor under a 



hood out in front. 



All of the wheels are 



arranged to turn for steer 



ing, this being accomplished 



through one steering wheel 



and column by attaching the 



steering crank by means of a 



rod to a vertical turn-bolt 



carrying three arms. One of 



these arms is a separate lever, 



while the other two really 



comprise one bar pivoted at 



To Make Your Lawn Attractive You 

 Must Edge It Evenly 



AN improvement on the ordinary 

 . lawn edger has been invented 

 Christian L. Schneider, of 

 Davenport, la. It not only 

 dges the lawn neatly but 

 cuts a trough at the same 

 time at a regulated depth. 

 The edger consists of a 

 J-shaped knife carried 

 on an arm which ad- 

 justs it to any height. 

 One of the wheels of 

 the edger runs on the 

 path surrounding the 

 lawn, with its outer 

 flange pressed 

 against the asphalt 

 so as to insure a 

 straight line. The 

 other wheel is ar- 

 ranged so that it will 

 keep parallel with 

 the wheel on the 

 path, whatever 

 irregulari ties 

 may occur in the 

 lawn over which 

 it travels. This 

 makes it easy to 

 push and insures 

 a straight edge. 



ADJUSTABLE KNIFE 



The outer wheel presses against the 

 edge of the path to insure a straight 

 line. A trough is dug at the same time 



