172 



NOTES ON CHAIN CABLES. 



type with the iDottom of the furnace carried on a car so as to permit of charging 

 by use of the traveUng crane. 



A comparison of the British and United States practice is shown in tabular 

 form in Fig. 34, Plate 107, and in graphical form in Fig. 35, Plate 108. With the 

 repeatedly increasing sizes of chain it is probable that the breaking stress required 

 for sizes about 3j4 inches will have to be somewhat reduced below those indicated 

 on the curve of the United States Navy in that this curve will fall ofif somewhat 

 after the manner of the Admiralty curve at 2^ inches. There appears to be no 

 good reason for lowering our requirements for sizes made up to the present time. 



The usual type of breaks met with in the testing of chain are shown in Fig. 

 36, Plate 109. The following tables are the result of examination of records of 

 routine tests of chain as manufactured at the Boston Navy Yard. It shows the 

 frequency with which breaks of different types occur: 



