806 



Mr. G. T. Bennett on the Parallel Motion of 



the hinges consecutively connecting ARSB are concurrent 

 in a finite point X instead of being parallel; and, further, 



Fig. 5. 



A model, of a special form, of the mechanism (a). The two vertical 

 plates have relative rotation about a virtual hinge. 



Fig. 6. 

 X 



The hinge TU of the model of fig. 5 being disconnected, the 

 mechanism flattens out as shown here in plan. 



that the hinges consecutively connecting ATUB are con- 

 current in a finite point Y. The piece A has then, relatively 

 to B, a motion of pure rotation about the line XY. Like 

 the Sarrut mechanism, this is a closed kinematic chain of six 

 pieces singular in possessing one degree of freedom. 



Another view of this last mechanism is useful. It may 



