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MR. WILLIAM FAIEBAIRN ON THE 



against the train ; which, in a train of 60 tons, gives a re- 

 sistance of 19 lbs. per ton. Assuming, therefore, the resis- 

 tance due to friction, exclusive of the motive powers of the 

 engine, to be 6 lbs., and the resistance of the air 19 lbs., 

 we then have an antagonist force of 25 lbs. per ton in con- 

 stant operation against the tractive power of a railway 

 train at 33 miles an hour. 



From these data, I have endeavoured to calculate the 

 power and size of engines necessary to overcome these re- 

 sistances (which, it must be borne in mind, are due to a 

 level plain) on different rates of inclination, or on gradients 

 varying from 1 in 20 to 1 in 200. Taking, therefore, 25 

 lbs. as the measure of resistance on a horizontal plane, the 

 following will exhibit, in a tabular form, the elements of 

 resistance to which a locomotive engine is subjected when 

 ascending gradients varying from 1 in 20 to 1 in 200, at 

 33 miles an hour : — 



TABLE OF RESISTANCES ON RAILWAY GRADIENTS, 



