Popular Science Monthly 



371 



can be operated with safety even on a 

 curve, because the little wheel is then 

 turned into the curve by its geared con- 

 nection with the air-screw. The safe and 

 sane brake system of the motor-bicycle 

 shines by comparison. 



The only worth-while advantage of a 

 unicycle over a bicycle is that it can be 

 steered by simply leaning to one side, but 

 this solitary advantage, exemplified in a 

 boy's play-hoop and largely utilized in the 

 old ordinary and "Star" bicycles, is de- 

 liberately abandoned in d'Harlingue's con- 

 struction. By rods (one of which is shown) 

 and the worm-gears before mentioned, the 

 air-screw is supposed to be swung to the 

 side in order to turn the big wheel. All 

 the complications arising from this mis- 

 understanding of the case are accepted. 



What are the supposed dimensions of 

 this unicycle? They are indicated by the 

 distance from the seat to foot-rest, which 

 must be about three feet to fit an average 

 man. That gives the diameter of the big 

 wheel as nine to ten feet and that of the 

 air-screw three and one-half feet, as men- 



Chassis 



tioned before. The chain-drive is about 

 six feet long. The aluminum shield in 

 front of the driver is bent and hammered 

 from a sheet at least six by four feet. 

 Though in this class of vehicles relative 

 proportions are vital, the engine and its 

 dimensions, as shown, must not be taken 

 seriously. By estimating bore and stroke 

 on scale with the rest, they would indicate 

 sixty to eighty horsepower at 1500 revolu- 

 tions per minute, but then the engine is 

 also shown as watercooled, yet with no 

 provisions for disposing of a radiator or 

 other bothersome detail. 



A jolly sport machine might be produced 

 on the basis of d'Harlingue's general idea 

 by radical simplification of his design, 

 including the omission of front wheel and 

 all gears and placing a little high-speed 

 one-cylinder engine directly behind the air- 

 screw. The shaft could be tilted upward a 

 little and the diameter of the big wheel 

 reduced to five or six feet. Braking could 

 be done by drags at the rear under foot 

 or hand control. But an engine starter 

 would be found indispensable. 



Pneumatic tire 



Inner rim 



Transmission 

 housing 



Propeller 



Roller 



Shield 

 Steering wheel for; 



Balance rod 

 Brake mechanism 



Foot vest 



Roller channel 



Steering and control 

 wheel not used in 

 high speeds 



Shock absorber 



Roller 



If a unicycle could be driven with a smaller resistance and at greater speed than a bicycle, if 

 it could be built more economically or compactly or could be operated more safely or enjoyably, 

 and if small air-screws could be made to apply a thrust against the atmosphere without a vast 

 loss of power as compared with the mechanical rotation of a driving wheel, the combination 

 might lead to desirable results. Alas ! Each of them is inferior, and their combination multiplies 

 their degree of inferiority compared with the motor-bicycle with mechanical transmission 



