CHAPTER III. 

 THE USE OF IRON. 



NOTWITHSTANDING the inability of metallurgists to de- 

 termine with certainty the precise point in its evolution when 

 iron is converted into steel, and conceding scientific uncer- 

 tainty as to technical definition, the well-known character- 

 istics of iron and steel exhibit radical differences, and prac- 

 tical metal-workers seldom err in determining each with cer- 

 tainty ; therefore comparison is entirely pertinent in consider- 

 ing both metals as materials for stand-pipe construction, and 

 the individual merits of each, referring to general utility, fit- 

 ness, and comparative cost, should receive consideration. 



Until 1880 iron plate was used almost exclusively in the 

 construction of metallic reservoirs, although a steel pipe is 

 recorded as having been erected as early as 1876, about which 

 time the commencement of the steel industry in the United 

 States may be said to have dated. From that time the in- 

 troduction of metallic members in structures slowly and tim- 

 idly advanced, criticised at each step; but, profiting by each 

 failure, overcame the difficulty until at the present time few 

 mills continue the practice of rolling iron shapes and plates for 

 structural work, and specifications calling for ferric members 

 are now practically obsolete. 



The United States Statistical Bureau of the Treasury De- 

 partment, for the year 1899, places the United States at the 

 head of the steel and iron producing countries of the world, 

 with a record of 13,620,703 tons of pig iron produced, of 

 which 78.1 per cent., or 10,639,857 tons, was converted into 

 steel. 



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