MECHANICS AND USEFUL ARTS. 73 



factorily, and this difficulty is now obviated by connecting the 

 two steel faces by a thin steel plate, like the letter II ; thus making 

 a complete rail of steel, except that the stem is slight, a sort of 

 skeleton stem, reinforced with a sufficient thickness of iron rolled 

 on each side to give the necessary strength and stiffness. 



Dephosphorization of Iron. Mr. Warren De la Rue (Ens:.) has 

 patented an invention, which consists in the introduction of lead, 

 metallic or oxide, into the converting vessels so as to be 

 thorougly diffused in the fluid metal, combining with the phos- 

 phorus in the iron, and the compound driven off* by oxidation. 

 Molten lead is introduced as soon as the blast has been turned 

 into the converting vessel. Compounds are entered with the 

 blast, in the shape of powder. 



Improved Steel Masts. This is the latest application of the 

 Bessemer product; substituting much lighter and slenderer tubes 

 of steel for. the wrought-iron article which had already been 

 applied to some extent in the British navy in place of "sticks." 

 The new mast is strengthened by transverse longitudinal plates. 



Steel Castings. Among the novelties in steel from Prussia, dis- 

 played in the Exposition, is a locomotive cylinder and valve-casing 

 cast solid in steel, difficult enough in iron (says " Engineering "), 

 but in steel very remarkable indeed, as one of the first steps in a 

 new art destined to produce the most important consequences. 

 The cylinder is bored out, to show the quality of the metal, and 

 the bored surface is as sound as the interior of a cast-iron cylinder 

 generally is. 



Hot and Cold Blast. An inquiry instituted by the British 

 Association has determined the ratio of strength in hot-blast iron 

 as 1,024.8, and of power to sustain impact as 1,226.3, to 1,000 in 

 cold-blast iron. 



Rolling a jifteen-incli Armor Plate. Sir John Brown has suc- 

 ceeded in rolling a plate of this thickness, intended for iron-clad 

 forts. If the result of testing prove satisfactory, such plates will 

 doubtless be substituted for the built-up system now adopted for 

 iron-clad forts. By a peculiar process of manufacture, the special 

 metal ingredients being kept a secret, these plates are said to 

 combine the toughness of copper with the hardness of iron. 



BRONZED CAST IRON. 



The productions of the Tucker Manufacturing Company, in 

 Boston, Mass., consisting of ornamental works in bronzed cast 

 iron, have recently attracted much attention both in America and 

 Europe. The material employed is made from several varieties 

 of American iron compounded together, with a comparatively 

 small admixture of the Scotch Coultness iron. A combination of 

 several important qualities is thus obtained, and a material is pro- 

 duced possessing smoothness in working, softness, and strength. 

 The castings, executed in green sand, undergo the customary 

 process of pickling in dilute sulphuric acid, after which they are 

 finished on their salient points either with tlie lathe or the emery 

 wheel, as may appear the most expedient for the polishing. The 



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