•— 80 — 
Test of Structure. 
ing cold through 90 degrees, and to a curve whose diameter is not 
over three times its thickness, without cracking. 
When nicked or bent, its fiactiu*e must be mostly fibrous. 
Biveta and pins shall be made from the best double-refined iron. 
The cast iron must be of the best quality of soft gray iron. 
All timber is to be of the best quality, free from wind sliakes, 
large knots, decayed wood, sap : or any other defect that would 
impair its strength or durability. 
Before the final acceptance of any bridge and after it has been 
in constant use for one clay, it may be tested by passing over it the 
specified train or trains or their equivalent at a speed not exceeding 
thirty (80) milea per hour, and bringing them to a stop at any 
point by means of the air brakes or any brakes ; or by resting the 
maximum train load upon the structure for twelve (12) hours. After 
such tests the structure must return to its original position without 
showing any permanent change in auy of its parts. 
