RAILWAY CONSTANTS. 



233 



creasing the resistance of the air. The rails were clean, and 

 the line had previously been accurately levelled from stake to 

 stake. 



The other members of the Committee being absent, the fol- 

 lowing experiments were made by Mr. Hardman Earle, Mr. 

 Edward Woods, engineer of the Liverpool and Manchester Rail- 

 way, and Mr. Alfred King. 



The line changes its direction by curves, all of which have a 

 radius of a mile at the parts marked in the following table with 

 an asterisk. 



In conducting the experiments, the train of wagons was al- 

 lowed, in each case, to pass without interruption from gradient 

 to gradient, tlie time of passing each successive stake being ob- 

 served and recorded. But as the motion on the different gradi- 

 ents are essentially distinct experiments, they have been sepa- 

 rately tabulated and reduced. In experiment I. the train was 

 brought to the stake No. 33 on the plane falling 1 in 178, and 

 allowed to descend by gravity fron\ a state of rest. It was al- 

 lowed to move on the next gradient until it reached the seven- 

 teenth stake, where it was stopped by the brake. 



In experiment II. the same train, in the same state, was 

 jjlaced at the fifty-seventh stake, at the summit of the plane, 

 falling 1 in 178, and was allowed, as befoi'e, to descend by gra- 

 vity from a state of rest. It moved along the successive gradi- 

 ents, and finally stopped 364 yards beyond the 51^ mile-post, 

 on the gradient falling 1 in 330, 



In experiment III. the high sides of the wagons were taken 

 down, and laid on the platforms of the wagons, so as to reduce 

 the surface exposed to the air without altering the gross weight 

 of the train. The train was then started again, as in the second 

 experiment, from the fifty-seventh post, and it descended the 

 successive gradients, and finallj'^ came to rest on the level at 

 three yards beyond the fifty-fourth mile-post. 



In the second and third experiments the train was started 

 from the same point ; in the one case it came to rest at 10,019 

 yards from the point of its departure, and descended 139 feet, 

 and in the other case it came to rest at 14,058 yards from the 

 point of its departure, and descended 175 feet. 



In the following table the results of the three experiments on 

 the gradient of 1 in 178 are exhibited in the same manner as in 

 the table of the experiments on the Whiston plane already given. 



