MOVEMENT 



43 



curve of movement presented in Fig. 27. The in- 

 strument employed in this experiment is applicable 

 for registering the progress of all kinds of machines. 

 It is called an " Olograph." 



The Odograph. — Fig. 30 represents a pedestrian 



Fig. 30.— Pedestrian pushing an odograph in front of him. 



pushing before him a light species of wheelbarrow. 

 The track of the wheel upon the ground represents 

 the distance traversed. The wheel of the barrow, by a 

 system of reducing wheels, controls the movement of a 

 strip of paper. Further, a tracing needle worked by a 

 clock moves across the paper at any desired rate. A 



