cxcviii GENERAL SUMMARY OF SCIENTIFIC AND 



The production of oj)en-hearth, or Siemens-Martin steel, as noted 

 in our last year's report, shows a steady increase, the production for 

 1875 being 9050 tons, as compared with 7000 tons in 1874, 3500 in 

 1873, and 3000 in 1872. The secretary of the association reports 

 that the product of 1875 was made by twelve establishments. 



The accompanying memorandum of the Siemens furnaces built 

 and in course of construction during the year 1876 to date of writ- 

 ing is given on the authority of Dr. Siemens' American agents, 

 Messrs. Richmond & Potts : 



Iron and steel melting-furnaces of various capacities, from 15 



to 50 tons in 24 hours 39 furnaces. 



Open-hearth steel-melting for the manufacture of homogene- 

 ous iron or steel upon the open hearth 4 



Double puddling- furnaces 12 



Crucible-steel melting-furnaces of 54 pots' capacity 2 



Spiegel melting-furnaces for the manufacture of spiegel 2 



Total 59 



The same authority places the product of the forges and bloom- 

 aries in the country in 1875 at 49,243 tons, as compared with 61,670 

 tons in 1874. 



The following, then, are the leading facts in connection with the 

 number, capacity, and character of the iron and steel establishments 

 of the country, as gleaned from the association's tables, bringing the 

 record up to January 1st, 1876 : 



Whole number of blast furnaces, excluding abandoned furnaces, 



January 1st, 1876 718 



Annual capacity of all the 713 furnaces, in net tons 5,439,230 



Whole number of rolling-mills, January 1st, 1876 332 



I Whole number of single puddliug-furnaces (double furnaces count- 

 ing as two) 4,475 



Total annual capacity of all rolling-mills in finished iron, net tons 4,189,760 



Annual caj^acity of all the rail-mills in heavy rails, net tons 1,940,300 



Number of Bessemer steel-works, January 1st, 1876 11 



Annual capacity in ingots, net tons 500,000 



Number of Bessemer converters 24 



Number of open-hearth steel-works, January 1st, 1876 23 



Annual capacity in ingots, net tons 45,000 



