METALS. 



adding spiegeleisen or other pure cast-iron rich 

 : bon. On the other hand, where mallea- 

 ble iron of a hnrd character is required the 

 lil:i-i is continued until more or less of the 

 carbon of the pi^r-iron is expelled, by which 

 means the metal retains more or less phospho- 

 rus, which imparts to it the property of hard- 

 ness, or cold shortness, as it is termed. 



Improved Method of welding Copper. In 

 welding copper the formation of an infusible 

 oxide has hitherto proved one of the worst ob- 

 stacles to the success of the operation. To sur- 

 mount this a writer in the English Mechanic 

 describes a process by means of which this re- 

 fractory oxide is converted into a readily-fusi- 

 ble compound, that disappears in the form of 

 slag. Phosphate of soda and ammonia (mi- 

 crocosmic salt) was first tried, and found to 

 answer perfectly ; but, being costly, a powder 

 consisting of one part of phosphate of soda 

 and two parts of boracic acid was substituted, 

 with equally satisfactory results. Practical di- 

 rections for welding copper are given as fol- 

 lows : 



This welding-powder should be strewed on the sur- 

 face of the copper at a red heat ; the pieces should 

 thcii be heated up to a full cherry-red or yellow heat, 

 and brought immediately under the hammer, when 

 they may be as readily welded as iron itself. For 

 instance, it is possible to weld together a small rod 

 of copper which has been broken; the ends should 

 be beveled, laid on one another, seized by a pair of 

 tongs, and placed together witli the latter in the fire 

 and heated; the welding-powder should then be 

 strewed on the ends, which, after a further heating, 

 may be welded so soundly as to bend and stretch as 

 if they had never been broken. 



It is necessary to carefully observe two thhips in 

 the course of the operation : 1. The greatest care 

 must be taken that no charcoal or other solid carbon 

 oomes in contact with the points to be welded, as 

 otherwise phosphide of copper would be formed, 

 which would cover the surface of the popper and 

 effectually prevent a weld. In this case it is only by 

 careful treatment in an oxidizing fire an 4 plentiful 

 application of the welding-powder that the copper 

 can again be welded. It is. therefore, advisable to 

 heat the copper in flame, an, for instance, a gas-flame. 

 2. As copper is a much softer metal than iron, it is 

 much softer at the required heat than the latter at its 

 welding-heat, and the parts welded cannot offer any 

 great resistance to the blows of the hammer. They 

 must, therefore, be so shaped as to be enabled to re- 

 sist such blows as well as may be. and it is also well 

 to use a wooden hammer, which does not exercise so 

 great a force on account of its lightness. 



Manganese- Bronze. Phosphor-bronze is now 

 largely used instead of brass and white-metal 

 for the bearings of heavy machinery. The 

 value of the phosphorus in this alloy consists 

 mainly in its strong affinity for oxygen, where- 

 by it cleanses the metals from the oxides, 

 which otherwise would prevent the perfect 

 combination of the copper and tin. An anal- 

 ogous alloy, with manganese taking the place 

 of the phosphorus, has been invented by P. 

 M. Parsons. This allo.v is known as " manga- 

 nese-bronze," and is formed by incorporating 

 manganese with the various bronze mixtures, 

 with the object of removing any oxide exist- 

 ing in the metal, by reason of the strong affin- 



ity of manganese for oxygen. The action of 

 the manganese in the alloy is visible in the 

 texture of the metal, a fracture of which, in- 

 stead of having a coarse, granular appear- 

 ance, is as closely and finely grained UK the 

 best qualities of steel, while the strength nnd 

 tenacity of the alloy are greatly increased, as 

 is shown by the results of tests made at the 

 Woolwich Arsenal. These results were as fol- 

 lows : 



Nos. 1, 2, and 3, were cast in iron moulds, and 

 Nos. la, 2a, and 3a, were forged from the same 

 castings. No. 3 had slight fiaws in it. The 

 hardness increases as the numbers rise, No. 3 

 being about as hard as our bronze coinage. 

 The sectional area of the test-pieces was .683 

 square inch, and their length 2 inches. 



From this it appears that the first sample 

 showed an ultimate strength equal to good 

 wrought-iron, while it is greatly tuperior to 

 the best gun-metal, for which sixteen tons per 

 square inch, with an elastic limit of seven tons, 

 are very high strengths. The effect of forging 

 this metal is also very striking, raising as it 

 does the strength to such high limits, and 

 practically giving a new and most valuable 

 metal to the world. 



The various applications of this new metal 

 involve many points of interest. Thus it would 

 evidently be of great service as a material for 

 screw-propellers, instead of the gun-metal and 

 brass now used to support the shaft. It might 

 be advantageously employed in the axle-boxes 

 and boiler-tubes of locomotives ; in hydraulic- 

 press cylinders and pressure- pumps of all kinds ; 

 in bearings or bolts wherever iron and steel 

 cannot be used on account of the corrosion 

 caused by salt-water ; but its possible adapta- 

 tion for the armor-plates of ships-of-war will 

 perhaps attract to this new metal most atten- 

 tion. Supposing the preliminary difficulties in 

 the way of preparing the armor-plates to have 

 been removed, and that we have a plate of the 

 quality marked 2a in Ihe above table, its re- 

 sisting power will be at least twice that of 

 wrought-iron. Besides, when struck by a pro- 

 jectile, the manganese-bronze plate would not 

 fly in pieces, neither would it crack or split. 

 In order to get through the plate the projectile 

 must fight its way inch by inch. Says a writer 

 in an English technical journal : 



Weight for weight, manganese -bronte would 

 probably cost 60 per cent, more than the present 

 rolled-iron plates. But if the resisting power be 

 double thut of iron the bronze plates might he half 

 the thickness, in which case we should have th 

 same efficiency, with a reduction of 85 per cent, in 

 the cost of the plate, and a diminution of one-half. 



