the Pendulum Accelerometer. 



267 



8*5 ft./sec. sec. positive. These give respectively about 

 800 lbs. per ton brake and GOO lbs. per ton starting effort. 



Fi<r. 8. 



(CL) 



QW.R*. Brake 



C.W.RX. S-»nT,« Q . 



(c) 



i5?9 Diagrams . 



OnJinaTes ■ Accelrrah 

 Abscissa? ■ Ti?rte 



The ordinate (acceleration) scale employed in the present 

 instrument is 10 ft./sec. sec. per inch, and is not quite open 

 enough to give pleasing diagrams in the railway. The original 

 model with its scale of 3 ft./sec. sec. per inch was better 

 suited to this class of work; but the much greater range and 

 general compactness o£ the 1904 model renders it much 

 handier and better for motor-car work, the purpose for which 

 it is primarily intended. 



In figs. 6 and 7 the time-scale (abscissae) reads from right 

 to left; in fig. 8 the time-scale reads in the opposite direction 

 from left to right. 



It has been remarked that a characteristic feature of brake 

 diagrams is the suddenness of the drop at the instant of 

 stopping. This is a very interesting and important point, 

 inasmuch as it is the cause of the " jerk " nearly always 

 experienced just as a train comes to rest; it was in fact in 



