PIG. 6. SECTION OF A STEEL RAIL CON- 

 TAINING TOO MUCH SULPHUR. THE 

 DARK AREAS ARE THE SULPHUR FLAWS. 

 MAGNIFIED 100 DIAMETERS 



PIG. 7. STEEL BAIL, MAGNIFIED 100 DI- 

 AMETERS. MADE OF GOOD STEEL, BUT 

 ROLLING FINISHED AT TOO HIGH A TEM- 

 PERATURE 



