158 



MB. WILLIAM FAIRBAIRN ON THE 



With the above load the engine, with steam at 75 to 90 

 lbs. on the inch, ascended the incline, which varied in the 

 gradients or rates of inclination, as per sketch, as follows:— 



^ - Il^'f-YAIIO* ;.-.. 702 YARDS - >rM>l 



CRADIEHTlIN 60 ; CRADICNT IIN46.ilHr8} LSVBL 



-2050 VARDa ' 



HOWIZOMTAL LIME 



In making the ascent, the engine and train were started 

 from nearly the middle of the station ; and, having run a 

 distance of about 160 yards, they entered upon the lower 

 gradient of 1 in 60, with a momentum of nearly 14 to 15 

 miles an hour. Unfortunately, however, the wheels slipped, 

 owing to the moist state of the rails at the entrance of the 

 curve on the gradient of 1 in 46, half way up the incline ; 

 the result was a repetition of the experiment. 



Ex'p. 2. — The same load in this experiment was carried 

 up the incline, a distance of 2050 yards, in 6 minutes and 

 4 seconds, being an average rate of travelling of 11'2, or 11^ 

 miles an hour. 



Exp. 3. — The " Scheldt" engine, 14 inch cylinder, 

 18 inch stroke, four wheels coupled, 4 feet 8 inches diame- 

 ter, and two trailing wheels, each 3 feet 6 inches diameter, 

 starting as before, with steam at 65 lbs. on the inch, took 

 the same load, 82 tons 2 cwt., up the incHne, a distance of 

 2050 yards, in 5 minutes and 30 seconds, being at the rate 

 of 12*7 or 12| miles an hour. 



Ex-p. 4. — In this experiment, with the same load and 

 same engine, 6 minutes and 10 seconds were expended in 

 the ascent, owing to the weighing-machine having broken 

 over which the engine and train had to pass, which pre- 

 vented the train from starting with the same momentum 

 as before. 



From these experiments it will be seen, that gradients of 

 considerable elevation can be worked by powerful engines 



