MECHANICAL PARADOXES. 



road which is in good condition, to draw the 

 jinrikisha loaded than to draw it empty. The 

 reason is simple and convincing. It depends 

 upon the gain obtained by putting a load 

 upon wheels. It is far easier to draw three 

 hundredweight in a light truck along a rail- 

 way platform than to carry one hundred- 

 weight on the back, making an extra weight 

 for the legs to support. The jinrikisha man, 

 returning with his carriage empty, has to 

 carry his own weight on his legs. It would 

 pay him well to get part of his weight off 

 his legs on to the wheels, even if they had 

 to carry in addition twice as much as they 

 take off his legs. But the jinrikisha is not 

 built so that he can ride it and propel it at 

 the same time, as one does a bicycle or a rail- 

 way trolley. The only way in which he can 

 transfer part of his weight to the wheels, while 

 drawing the jinrikisha along the roads, is by 

 leaning on the shafts. 



But the body of the carriage is so light 

 that the slightest pressure on the shafts sends 

 it up ; and to make the shafts able to carry 

 an appreciable part of his own weight, he 

 must counterpoise this by putting a consider- 

 able mass in the seat of the vehicle. And the 

 counterpoise must be a good deal heavier 

 than the part of his own weight of which he 

 is to be relieved, since its point of application 

 is nearer to the fulcrum or bearing point, 



