K. MECHANICS AND ENGINEERING. 391 



iron is effected. This metallic iron is then subjected to very- 

 intense heat on the open hearth of a Siemens regenerative gas- 

 furnace, and is .dropped in certain given quantities or series 

 of instalments into a bath of cast-iron previously prepared in 

 the furnace. This operation is continued until the requisite 

 degree of decarbonization is arrived at ; the manganese is 

 added in the form of ore or spiegeleisen. The quantity of 

 molten metal thus produced in one charge is about four tons. 

 It is dipped into a ladle and poured into iron moulds in the 

 usual way, and forms steel of the highest quality. To those 

 acquainted with the ordinary way of making steel, the supe- 

 riority of this process will be manifest, while as regards cost 

 it effects a great saving. One ton of steel ingots maybe pro- 

 duced with a ton and a half of cheap small coal. The ordi- 

 nary Sheffield process requires from five to six tons of fuel for 

 one ton of steel. 15 A, April 9, 1870, 488. 



* APPLICATION FOR PREVENTING OXIDATION OF IRON. 



The following composition is used for preventing the oxida- 

 tion of iron, especially the bottoms of iron ships : Seventy 

 pounds of powdered sulphur, five pounds of the lye of caustic 

 potash of thirty-five Beaume, and one pound of copper filings 

 are to be heated together until the sulphur and copper have 

 completely dissolved. During the process, seven and a half 

 hundred weight of tallow and one and a half hundred weight 

 of turpentine are to be heated together in another vessel until 

 the tallow lias completely disappeared. The two solutions 

 are then to be carefully stirred together when hot, and ap- 

 plied immediately with a brush. 5 C, xxvil, 216. 



FORGING LARGE MASSES OF IRON. 



A paper was read by Colonel Clay, at the Liverpool meet- 

 ing of the British Association, in reference to the mode of 

 overcoming the difficulties in the way of economical forging 

 of large and solid masses of iron. Furnaces of the old style 

 of construction were said to be most imperfect and unreliable, 

 some of them requiring renewing once a fortnight. Mr. Sie- 

 mens had introduced the principle of heating large forges by 

 means of gas, which attained intense degrees of heat, and 

 saved at least fifty per cent, in fuel, but it was not until re- 

 cently that the principle had been applied to heating large, 



