VI. METALLURGY. 545 



2765. Tubes tested with Gunpowder, to show the strength 

 and ductility of Whitworth fluid compressed steel. 



Sir Joseph Whitworth fy Co., Limited. 



These tubes were tested to ascertain the strength and ductility of fluid com- 

 pressed steel, as made for guns, torpedoes, &c. 



The ductility is shown by the metal belying under the strain, instead of 

 flying in pieces. 



2766. Sample Pieces of Metal, used for testing, to ascertain 

 the strength and ductility of metal. 



Sir Joseph Whitworth $ Co., Limited. 



There is no scientific line of demarcation between iron and steel. Sir 

 Joseph Whitworth proposes that such a line should be established, and that 

 the quality of a metal should be represented by two numbers, showing its 

 strength and ductility. 



These test pieces are similar to those in use by Sir Joseph Whitworth in 

 testing his fluid compressed steel, to ascertain the proportions of strength and 

 ductility which is required for different purposes. 



The greater the strength, and the greater the ductility, the higher the 

 quality of the metal. 



2767. Sections of Steel Ingots, one cast in the ordinary 

 way, the other compressed while in a fluid state. 



Sir Joseph Whitworth $ Co., Limited. 



By the ordinary method 'of manufacture, it is found to be impossible to 

 produce sound ductile steel suitable for constructive purposes, owing to the 

 presence of honey-combed air-cells, which are altogether uncertain in their 

 size and situation, and undiscoverable until laid bare by fracture or sections. 



By compressing the metal while in a fluid state this defect is overcome, and 

 a sound reliable material produced. This is shown by the two ingots, one cast 

 in the ordinary way, and the other compressed while fluid. 



2767a. Sample of Iron molten by means of compressed air. 



Mr. Enfirjils, Paris. 



2769. Set of cubical specimens of Coal, Ironstone, Lime- 

 stone, and Cold Blast Iron. Illustrating the exact propor- 

 tions, both in weight and bulk, of the minerals consumed in the 

 blast furnaces for the production of cast iron at the Bowling Iron- 

 works. The Bowling Iron Company, Limited, Bradford. 



The coal is coked and the ironstone calcined preparatory to their intro- 

 duction into the blast furnace. 



2770. Case showing successive processes of Gold 

 Assaying. 



1. Tray on which assays are placed when ready for the furnace. 



2. Muffle containing cupels. 



3. Tray for annealing the buttons after being rolled or flatted. 



4. Tray of platinum cups for " parting " the assays. 



5. Platinum boiler in which the assays are treated with strong 

 nitric acid. 



6. Assay balance, capable of indicating the ^yVo^li of a grain 

 when loaded with 7 ' 5 grains. 



39508. M m 



