MODERN BRONZES. 539 



verse strength, toughness, and hardness, the facility with which it can 

 he cast, and the soundness and uniformity of the castings produced. 

 This quality is used for wheel-gearing, supports and connections of 

 machines, crank-pin brasses, the shells of main and other bearings 

 of engines, axle-boxes, and parts of locomotive-engines. It is also 

 adapted for statuary and for large bells. Its most important appli- 

 cation appears to be for making screw-spellers, for which, in its 

 qualities of strength, non-corrosiveness, and perfect trueness in cast- 

 ing, it seems to be superior to any other substance yet found. 



The qualities numbers four and five have no particular claim to 

 strength, but are useful for bearings, slide-valves, slide-blocks, piston- 

 rings, and other purposes in which friction has to be taken account of. 



Delta-metal, the second and latest example of the successful addi- 

 tion of iron to bronze, was introduced, in 1883, by Mr. Alexander Dick, 

 who named it with the Greek equivalent for the initial of his surname. 

 His preliminary experiments were directed to removing the inequalities 

 in the properties of the iron-bronze alloys previously attempted, and 

 he found that all depended on getting exactly the right proportion of 

 iron and preventing its oxidation during the process of remelting. 

 Delta-metal in color resembles gold alloyed with silver. It can be 

 worked hot and cold. When melted, it runs freely, and the castings 

 produced from it are sound and of a fine, close grain. It can not be 

 welded, but can be brazed, and, when of suitable thickness, " burned." 

 The varieties designed for working hot are capable of being stamped 

 or punched, similar to wrought-iron and steel, into a variety of arti- 

 cles which have hitherto been cast in bronze or brass. This property 

 is of much importance, for the articles thus turned out are cheaper 

 and stronger than brass-castings. The iron introduced into the com- 

 pound by Mr. Dick's process is really chemically combined ; and the 

 alloy does not rust, and has no action on the magnetic needle. Delta- 

 metal may be used to replace the best brass and gun-metal, and in 

 many instances iron and steel also for parts of rifles, guns, and tor- 

 pedoes, tools for gunpowder-mills, parts of bicycles, gongs, various 

 domestic articles, spindles for steam- and water-valves, plungers, pump- 

 rods, and boats. 



Phosphor-copper is a preparation devised by Mr. W. G. Otto, of 

 Darmstadt, for the purpose of furnishing engineers and founders with 

 a compound, by adding certain proportions of which to a given bulk of 

 metal they can obtain a phosphor-bronze suitable for various purposes. 



An article called phosphor-manganese-bronze is in the market, but 

 the manufacturer has not furnished a description of it. 



Phosphor-lead bronze, introduced in 1881 by Messrs. K. H. Kuhne 

 & Co., of Lobau, near Dresden, is regarded as specially adapted for 

 all purposes where metal is subjected to constant wear or continuous 

 friction. The introduction of lead into its composition and its homo- 

 geneousness are said to give it special properties, by reason of which 



