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Transactions of the Society. 



microscope reveals a certain amount of free or uncombined iron, 

 easily discernible as white silvery veins, as will be seen later. This 

 is termed " ferrite." 



" Hyper eutectoid " steel is more highly carburized than the first 

 mentioned, and contains no ferrite, its place being taken by the 

 intensely hard and brittle " cementite." In this paper I propose 

 dealing only with the hypo -eutectoid form, and have selected from 

 my records a recent research made on a rail which did not render 

 the service given by others in similar positions. 



The illustration (fig. 1) shows the piece of rail as received ; it 

 was about 12 inches long, and from this all the test-pieces were 

 cut, as indicated by the dotted lines. Nos. 1 and 2 were complete 

 sections, and after being carefully polished were first subjected to 

 a laboratory adaptation of the Brinell Test, by which a hardened 

 ball is driven into the steel by a force which remains constant in 



Fig, 1. 



each case, so that it naturally follows that the spherical depression 

 will vary in accordance with the resistance opposed to the force 

 expended. By measurement of the indents the degree of hardness, 

 or " hardness number," can be arrived at. Both No. 1 and No. 2 

 sections emerged fairly well from this test, the hardness numbers 

 being reasonably uniform, as will be seen later. Both were then 

 prepared for " sulphur-printing." 



In practically all commercial steels carbon, manganese, silicon, 

 sulphur and phosphorus are present in carefully-regulated pro- 

 portions, but should sulphur or phosphorus be in excess they are 

 highly detrimental, although little objection can be raised providing 

 both are kept within certain limits. Of course neither exist in steel 

 as simple elements, but effect chemical combinations with the 

 other elements. Unfortunately both sulphur and phosphorus are 

 exceedingly difficult to entirely eliminate. 



The presence of sulphur can be detected and recorded by 

 sulphur-printing, for which purpose sheets of silver paper are 

 saturated in a solution of H2SO4, and afterwards placed on an 



