AMERICAN INDUSTRIES SINCE COLUMBUS. 749 



at this critical period of the process that the person in charge of 

 the operation judges of the proper time to " turn down" the " ves- 

 sel " and cut off the blast. When that time arrives, the vessel is 

 turned with its body in a horizontal position, and a certain weight 

 of a metal called spiegeleisen is added in a molten state, and the 

 converter is then turned still farther down into the position shown 

 in Fig. 58, and its contents poured into a casting ladle H, attached 

 to the end of the arm of a crane, G. This ladle is provided with 

 a, " tap-hole " in its bottom, which can be closed by a valve attached 

 to the lower end of the spindle L (Fig. 59). Of course, the in- 

 terior of the ladle as well as the valve and its spindle are made of 

 the best fire-resisting material obtainable. The spindle L is raised 

 or lowered to open or close the " tap-hole " by means of a lever, N 

 (Fig. 58), which operates a vertical slide-bar to the upper end of 

 which the spindle L is attached. The crane-arm G is attached to 

 the upper end of a cylindrical ram or post capable of moving up- 

 ward as well as rotating in a hydraulic cylinder, E. The ingot 

 molds (of which one is shown at K) are placed in a circle, whose 

 center is that of the cylinder E, and are filled in succession by 

 swinging the crane about the same center. The molds K are 

 made of cast iron, and are smaller at the top than at the bot- 

 tom, in order that they may be readily " stripped " off the ingots 

 of steel. 



The apparatus shown in the above-described figures was the 

 invention of Henry (now Sir Henry) Bessemer. It is remarkable 

 for its ingenuity and perfect adaptation to the needs of the new 

 process, and, notwithstanding the lapse of over thirty years and 

 the accumulated experience of multitudes of metallurgists and 

 engineers, substantially the same apparatus is to-day in use in 

 every Bessemer steel-works in the world. Of course, there have 

 been many changes and some improvements in details, but its 

 essential features remain as they were planned by their inventor 

 thirty-six years ago the converters still turn on their trunnions 

 and receive their air-blast as has been described ; the casting-ladle 

 continues to be attached to a hydraulic crane and to discharge its 

 contents through a valve-closed " tap-hole " in its bottom ; hy- 

 draulic cranes are still used to rapidly handle ingots and molds ; 

 and these foundation facts of ingenious design promise to con- 

 tinue in use for all time as enduring evidences of great originality 

 in the selection and adaptation of means to ends, and fairly enti- 

 tle their inventor to a foremost place among the mechanicians of 

 the century. 



[ To be continued.] 



