STREMMA TOGRAPH. 101 



Compression between front and rear driver, 2,126 lbs. 



Tension under rear driver, 26,454 



Compression between rear driver and front tender, 2,362 '' 



Tension under front tender wheels, 12,755 '' 



Compression between front truck wheels, 1,181 "■ 



Tension under rear front tender wheels, 13^463 '*' 



Compression between front and rear truck, 2,362 "■ 



Tension under rear front truck wheel, 12,991 "■ 



Compression between front and rear wheels, 1,889 '' 



Tension under rear tender wheels, 12.755 " 



Compression between rear tender wheel and car truck,.... 709 " 



Tension under front car wheel 14,408 '^ 



Compression between ist and middle wheel, 1,181 '' 



Tension under middle car wheel, ,....14,172 '^ 



Compression between middle and rear wheel, 3^443 '' 



Tension under rear truck wheel, 13? 2 24 '' 



Compression in center of space between trucks, 00 ' ' 



The other wheels of the several trucks of the cars indicate 

 nearly the same stresses. 



The record of the other train on the slide is quite similar to 

 the one just described. The tremors and vibrations which are 

 set up by the rapid reversal of the stresses, the slight irregulari- 

 ties in the surface of the wheels are very decided, as the records 

 show. 



On the wavy surface of the rail on which these records were 

 taken, the combined static and dynamic effects in producing 

 stresses are about double at 40 miles per hour of the static 

 effects from the same wheel loads. This rate is much higher 

 than has been found upon smooth rails. 



The importance of having the rails well finished, as we have 

 compelled the mills to do for some years, is very fully confirmed. 

 The necessity of having smooth wheels, perfectly round is very 

 important, particularly for fast trains. 



In a number of records on the same rail, the engines when 

 using steam to accelerate the train, the front driver has shown 

 greater stress than the rear driver except in one instance. 



The position of the counter-balance in all of these experiments 

 has been noted by the eye, and up to 35 miles per hour it has 



