203 REPORT — 1873. 



industry has been brought to its present important position. My object is to draw 

 attention to this material as to its use and application for stnictimd and engineering 

 purposes. 



The steel produced by the Bessemer process was at a very early stage employed 

 in rails and wheel-tires. In both these applications the object sought was endurance 

 to resist the effects of wear, and toughness to prevent fracture by blows. There 

 does not exist at present sufficient information to determine accurately the relative 

 values of steel and iron when used for these pui-poses. As used for wheel-tires, 

 steel had to compete with iron of the highest quality, but it is nevertheless intro- 

 duced on most of our railways. The iron used in rails was not of such high quality, 

 and the difference in duration shows a very marked advantage in the employment 

 of steel, the duration of steel rails being variously estimated at from three to six 

 times that of iron. 



Steel is also extensively used for ships' plates, and by the AVar Department for 

 lining the interior of the heaviest guns ; while Sir Joseph Whitworth and Messrs. 

 Krupp make guns entirely of steel, tliough for these purposes the metal is of 

 different quality and differently treated, in order to withstand the enormous con- 

 cussions to which it is subjected. 



And, further, we liave steel used in railway-axles, crank-axles for engines, in 

 boilers, in piston-rods, in carriage-springs, and ibr many other purposes. 



But, notwithstanding these various employments of steel, there has been, and 

 there continues to be, a difficulty in applying it to engineering stmctures in this 

 country. 



The want of knowledge of the physical properties of steel having been the subject 

 of remark at a discussion at the Instituticm of Civil Engineers in 1808, a Committee 

 (composed of Mr. Fowler, Mr. Scott Russell, Captain Gallon, Mr. Berkley, and 

 nij'self) undertook to conduct a series of experiments upon this subject. Our 

 services were of course rendered gratuitously ; but the expenses of carrying out this 

 inquiry, and the samples of steel to be tested, Avere liljerally furnished by the firms 

 of Messrs. Bessemer, Messrs. Jno. Brown & Co., the Barrow llfematite Company, 

 the Bolton Iron Company, Messrs. Clamniell & Co., Messrs. Lloyds, Fosters & Co., 

 the Newarlv Bridge Company, ]\Iessrs. Naylor, A'ickers & Co., Messrs. Turton & 

 Sons, Messrs. Firth & Sons, and Messrs. Siemens. 



The experiments recorded consist of four series. 



The first were made for the Committee by !Mr. Kirkaldy with his testing- 

 machine in l^onJon, and were chiefly directed to ascertain the relation which 

 subsists between the resistances of tension, compression, torsion, and transverse 

 strain. 



In this series of experiments twenty-nine bars, 15 feet long, were used, each 

 bar being cut into lengths, and turned or planed into suitable forms for tlie 

 respective tests, so that a portion of each bar was subjected to each of the above- 

 mentioned tests. 



The tensile resistance varied in the different qualities of steel from twenty-eight 

 to forty-eight tons per inch, and the experiments established conclusively that the 

 relation subsisting between the several resistances of tension, compression, and 

 transverse strain is throughout practically the same as in wrought iron ; that is 

 to say, that a bar of steel whose tensile strength is 50 per cent, above that of 

 wrought iron will exhibit about the same relative increase of resistance under the 

 other tests. 



They further showed that the limit of elasticity in steel is, like that of wrought 

 iron, rather more than half its ultimate resistance. Tlie total elongation under 

 tensile strain, and the evidences of malleability and toughness, will be referred to 

 hereafter. 



The second series recorded in the book published b}' the Committee gave the 

 results of tempering steel in oil and water. They were made by the officers of the 

 gun-factory at the Royal Ai'seual at ^^'ool\\•ich, and show a remarkable increase 

 of strength obtained by this process. This property of steel is now fully recognized 

 and made use of in the steel which forms the lining of tlie largest guns. 



The third series of experiments was made by the Committee upon bars 14 feet 

 long, li inch in diameter, with the skin upon the metal as it came from the rolls. 



