202 HEROES O F INVENTION AND DISCO VER Y 



Mr. Bessemer himself was by no means satisfied with the 

 result of his first experiments. He was satisfied that he had 

 hit upon the right principle ; the question was, could he correct 

 those serious defects in the process which to practical men 

 seemed to present an insuperable obstacle in the way of the 

 adoption of his invention ? 



It was a case for persevering experiment, and experiment 

 only. The inventor's patience and perseverance were found 

 equal to the task. Assisted by Mr. Longsdon, he devoted him- 

 self for several years to the perfection of his process of 

 conversion, in which he at last succeeded. 



We can only briefly refer to the alterations and improve- 

 ments in the mode of conducting it which he introduced. 

 In the first place, he substituted for the fixed converting 

 vessel, a movable vessel, mounted on trunnions, sup- 

 ported on stout pedestals, so that a semi-rotatory motion 

 might be communicated to it at pleasure. It was found 

 both dangerous and difficult, while the converting vessel 

 was fixed, to tap the cupola furnace ; for the blast had 

 to be continued during the whole time the charge was run- 

 ning out of the vessel, in order to prevent the remaining 

 portion from entering the twyers. By the adoption of the 

 movable converting vessel, this source of difficulty was 

 completely got rid of, while the charging of the vessel with the 

 fluid metal, the interruption of the process at the precise 

 moment, and the discharge of the metal when converted, were 

 rendered comparatively easy. The position and action ot the 

 twyers were also improved, and the converting vessel was lined 

 with " ganister," a silicious stone, capable of resisting the action 

 of heat and slags, so as to last for nearly a hundred consecutive 

 rharges before becoming worn out, whereas the lining of fire- 



