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THE POPULAR SCIENCE MONTHLY. 



added from time to time as the work progressed, and some- 

 times the mass of fuel and ore was heaped up three or four feet. 

 After an hour and a half or two hours of blowing, most of 

 the iron in the ore was found in a pasty condition at the bot- 

 tom of the hearth, in a bath of liquid " cinder " formed from 

 the impurities of the ore and the ashes of the fuel ; the blast was 

 then augmented and most of the " cinder " drawn off through 

 a " tap-hole " in the front side of the hearth, after which the 

 pasty iron was lifted by bars until it was opposite or some- 

 what above the tuyere, and was there heated and manipulated 

 until it became a spongy but coherent mass or " ball " of forge- 

 able iron, twelve or fifteen inches in diameter, whose numerous 



Fig. 11. Removing a Ball from a Catalan Forge. 



cavities were filled with a more or less fluid cinder. For the 

 purpose of expelling this " cinder " and imparting greater density 

 and coherence to the iron, the ball was then removed from the 

 fire (Fig. 11) and taken to a "trip-hammer"* (Fig. 12) and 

 " shingled." 



The resulting "bloom," roughly cylindrical or rectangular in 

 shape, represented about three fourths of the iron contained in 

 the ore used ; the remainder went into the cinder and was lost. 

 The weight of the " bloom " obtained at a single operation was 

 usually from three hundred to three hundred and fifty pounds. 



* So called from the fact that it is " tripped up " and allowed to fall, by the pins on the 

 rim of the smaller of the two wheels shown in the illustration (Fig. 12). This form of ham- 

 mer is also called a " shingling hammer." 



