HOSE, COUPLINGS, AND FITTINGS 387 



"Stretching Test. Another section 1 in. long will be cut from 

 the balance of the 5-in. piece and the inner tube or lining will be 

 separated from the ply and cut at the lap. Marks 2 in. apart 

 will be placed on this section, and then the section will be 

 quickly stretched until the marks are 8 in. apart and imme- 

 diately released. The section will then be remarked as at first 

 and stretched to 8 in. and will remain so stretched 10 min. 

 It will then be released and 10 min. later the distance between 

 the marks last applied will be measured. In no case must the 

 test piece break or show a permanent elongation of more than 

 J in. between the marks last applied; 1-in. strips will also be 

 taken from the cover and subjected to the same test. 



"Tensile Test. Another section 1 in. long will be cut from 

 the remainder of the 5-in. piece and the rubber tube or lining 

 will be separated from the ply and cut at the lap. It will then 

 be reduced in the middle for a distance of 2 in. by i in. wide 

 parallel. The parallel section shall be spread to the full width 

 of 1 in. at the end by curves of in. radius. This specimen 

 shall be stretched uniformly by gripping the enlarged ends, and 

 in no case should the tensile strength per square inch be less 

 than 400 lb., nor the elongation at the time of failure less than 

 8 in., measured by marks placed originally 2 in. apart before 

 breaking. 



"If the test hose fails to meet the required tests, the lot 

 from which it was taken may be rejected without further 

 examination and returned to the manufacturer, who shall pay 

 the freight charges in both directions. If the test hose is 

 satisfactory the entire lot will be examined and those complying 

 with the specifications will be accepted. 



LABEL FOR AIR-BRAKE HOSE 

 Sheet M. C. B. 18 



"In 1902 the label for hose, as shown in the specifications for 

 air-brake hose, was made a standard. Revised in 1903. The 

 specification for its use is as follows: 



"Each standard length of hose must be branded with the 

 name of the manufacturer, year and month when made, and 

 serial number, the initials of the railway company, and also 



