1884.] NEW YORK ACADEMY OF SCIENCES. 9 



pens of apparatus located in various portions of the car and 

 truck; and, on the lower side, the pens which give the indica- 

 tions of the track rails. The first and last are controlled 

 entirely by mechanical motions and connections. 



The connections which operate the mechanism to record 

 surface undulations of the rails, are so made as to only transmit 

 the irregularities and deflections of the rails ; the up and down 

 motions or jar of the car body are eliminated. This enables the 

 work to be repeated for comparison, and for this reason suc- 

 ceeding diagrams of the same track are of increasing value. 



The various indications will be understood by reference to the 

 diagrams shown in Fig. III. 



The apparatus, as shown in Figs. I. and IL, is arranged to take 

 the dynamometrical curve and inspect the track at the same 

 time. The two distinct operations, liowever, in my practice are 

 seldom conducted at the same time. 



For the dynamometrical work a special draw-ljar is required ; 

 fastened to the frame work of the car is a fluid chamber, so 

 arranged that any tension or pressui-e against the draw-bar is 

 communicated thi-ough mechanism to the pen which indicates 

 or draws the dynamometrical curve; the greater the tension or 

 pressure of the draw-ljar the farther the pen moves from the 

 base line. 



The cross-head of the measuring-spring (see Fig. II.) to which 

 the dynamometrical pen is attached carries a rod with a little 

 disc, which moves out or in from the center of the larger disc, 

 as the tension is greater or less on the draw-bar. These two 

 discs form the integrating apparatus which mechanically de- 

 termines the area of the dynamometrical curve ; each revolu- 

 tion of the smaller disc constitutes a ratio of work for definite 

 springs, and is electrically recorded upon the paper, shown by 

 the breaks in line 288, Fig. III. 



The ratios are counted and multiplied l)y a constant for each 

 pair of springs, which gives the foot-pounds of work per mile, 

 or any other selected distance. 



The ordinates of the curve can also be measured, and the foot- 

 pounds of work obtained by calculation, l)ut it involves much 

 labor. The speed of the train can be ascertained at any instant, 

 as shown by the chronograph lines 289 and 290, indicating 

 seconds and ten seconds. 



A delicate clock movement, with circuit breakers and closers. 



