JOSIAS CHRISTOPHER GAMBLE 57 



and Son, then to Gamble, Son, and Sinclair, 

 and then back to Jos. C. Gamble and Son, 

 which it has retained till the present day, 

 when it consists of Colonel Gamble, in 

 partnership with his four sons, Josias, William, 

 David and George. 



The patent which Mr. Gamble took out in 

 1839, and which he first put into operation at 

 Gerard's Bridge Works, claimed : 



First, iron retorts worked in connection 

 with each other. Two decomposing furnaces 

 are connected with a roasting furnace. 



Second, the iron retorts constantly worked 

 through a door, open or partly open while 

 the process is going forward, the draught of 

 the chimney drawing in a portion of the 

 external air with the muriatic acid into the 

 receivers. This claim was disclaimed in 

 January, 1845, on the ground that the words 

 have a doubtful meaning. 



Third, the use of receivers so arranged 

 that the acid can pass from one to the other 

 or can be cut off at pleasure when strong 

 acid is required ; these are filled with glass or 

 pebbles. 



Fourth, the use of earthen stills with 



