278 



SECTION MECHANICS. 



This intimate connexion between the driving mechanism of the 

 direct-acting and oscillating engines was never, I think, recognised 

 until Reuleaux pointed it out. They are the same chain., the only 

 kinematic difference between them being in the link which is fixed. 

 But we can go further ; we can fix, for instance, the crank- We ge'" 

 thus a mechanism doubtless familiar to most of my hearers (Fig. 9), 





- r 



Figure 9. 



and which has often been described and applied. Sir Joseph Whit- 

 worth, for instance, has used it as a quick return motion. If the link b 



