MECHANICAL PARADOXES. 



which the only important point is the distance 

 from axle to connecting-rod. 



Take, for instance, the inventor's bent 

 crank ABC. Since it is of rigid metal, C 

 will always remain at the same distance from 

 A. We may, therefore, add a rigid metal 

 connection between A and C, as D at F E, with- 

 out in any way interfering with the power pre- 

 viously transmitted through F G E. We may 

 then make a further modification, removing 

 altogether the limbs F G and G E, since the 

 bar D will now keep E in its previous relation 

 to F. In other words, a straight crank H K 

 will have exactly the same effect as the bent 

 crank ABC, provided the distance from H to 

 K be the same as that from A to C. 



The last suggestion should appeal to those 

 who have an eye and an imagination for 

 mechanical truth ; but for those who can 

 follow a simple proof, that is also available. 



The inventor's theory is that a force applied 

 vertically at C through C B exercises a greater 

 leverage at B through the arm A B than it 

 would do at C if there were only a straight crank 

 A C. Let L M N have the same angles and 

 proportions of parts as ABC. The force is 

 applied vertically at N and communicated to 

 M by the arm M N, which is rigidly connected 

 with the arm L M. There is, therefore, a ver- 

 tical pressure at M equal to that applied at N. 

 Let the magnitude of the force be represented 



108 



