METALLURGY. (MISCELLANEOUS.) 



391 





dustries, in the drawing of sheet metals in the 

 press. One of the limitations of the method arose 

 out of the hardening of the metal during treat- 

 ment. In forging steel, small articles were pro- 

 duced satisfactorily in quick-acting drop-presses; 

 large articles demanded the slowly acting hy- 

 draulic press. In dealing with the problem of 

 cutting action, the author pointed out that cut- 

 ting was largely composed of shearing. In turn- 

 ing mild steel, for example, the tool acted by com- 

 pressing the material in front of it until ruptures 

 occurred by shearing in front of the chip. In an 

 extremely plastic substance, or one which was 

 both elastic and plastic, chips could be removed 

 without shearing action, because they would be 

 sufficiently elastic or plastic to bend or flow with- 

 out rupture, and would permit the passage of the 

 tool. In planing wood with the grain the chips 

 would not be removed by intermittent shearing, 

 but, if ruptured at all, would be ruptured by bend- 

 ing. Should rupture occur in advance of the cut- 

 ting edge of the tool, perfect cutting action would 

 cease, and rupture of the chip would not be an 

 essential part of the cutting action. Passing to 

 the action of grinding machinery, the author 

 pointed out that the removal of metal by abrasion 

 at high velocities was probably largely due to the 

 heating of the particles removed. 



Facts respecting the workings and economy of 

 installations of electric machinery for the trans- 

 mission of power were given in a paper read by 

 Mr. D. Selby-Bigge at the summer meeting of the 

 Iron and Steel Institute. In one of the Westing- 

 house Company's works a reduction of more than 

 32 per cent, in coal consumption was made by the 

 adoption of electric transmission. An article was 

 quoted from the journal Traction and Trans- 

 mission in which it was said that the saving 

 due to the electric transmission of power was 



?robably nearer 60 per cent, than 50 per cent. 

 Q a colliery the sum of 1,500 was saved per an- 

 num at one shaft by the use of electric motors for 

 pumping. In another colliery, where the pumps 

 were originally driven by endless wire rope, the 

 expenditure of a little more than 3,000 in 

 electric plant resulted in the annual saving of 

 between 1,500 and 1,800. A similar case was 

 quoted of a Scottish colliery, and other details 

 were set forth as to the cost of labor and material 

 for driving by electricity and other means of 

 transmitting energy, all more or less in favor of 

 the former. The importance of utilizing gas from 

 blast-furnaces was also dealt with in this paper. 

 Gas-engines have been driven in this way, and 

 they should be made to actuate blowing-engines 

 or dynamos from which currents could be dis- 

 tributed throughout the works. At Seraing a 

 Cockerill gas-engine of large size used about 100 

 cubic feet of average blast-furnace gas per ef- 

 fective horse-power per hour. This was less than 

 one-fourth of the gas that would have been burned 

 in the boilers of good modern condensing steam- 

 engines. It is estimated that for every 100 tons 

 of coke used in an ordinary Cleveland blast-fur- 

 nace there is a surplus of at least 1,500 horse- 

 power. " It would be impossible," the author said, 

 " to overrate this new development in power pro- 

 duction." The sources from which electricity can 

 be produced most economically for the transmis- 

 sion of power when sufficient sources of water- 

 power are not accessible " will be undoiibtedly 

 due to the development of large power gas-engines 

 making use of the surplus gases from the blast- 

 furnaces, which would otherwise be wasted." 



Miscellaneous. The finest monochromatic 

 shades can be produced on platinum and German 

 silver by the electrolytic decomposition of manga - 



nous salts, the metal to be treated being connected 

 with the positive electrode. In determining the 

 strength of the manganese solution, the power of 

 the electric current should be considered; the 

 weaker the current the stronger the solution 

 should be. The color produced changes greatly 

 and quickly, so that the current must be broken 

 the instant the color desired has been produced. 

 Golden yellow, green, and purple are obtained 

 with particular brilliancy. The metal should be 

 removed from the bath as soon as the current is 

 stopped; rinsed with distilled water; and care- 

 fully dried with soft blotting-paper. If manganese 

 chloride or lead acetate is used, the colors appear 

 in rings instead of as a uniform layer, and of all 

 the colors of the rainbow in the softest shades the 

 paramount hues being green, golden yellow, and 

 blue, while each whole system of rings is sur- 

 rounded by a yellow zone. 



The observation is made by G. P. Blakiston 

 that pieces of wrought iron or steel in crucibles 

 or open-hearth furnaces melt inside first, leaving 

 an outer film which is later in melting. The 

 author's explanation of the phenomenon is that 

 the melting-point of the outer layer is made 

 higher by oxidation, while the melting-point of 

 the unoxidized metal within is not changed. 



Finding from comparative examinations of their 

 microstructure as revealed in ends that have been 

 sawed that rails that have been hot-sanded are 

 finer-grained than those which have been cold- 

 sanded, S. S. Martin infers that it is best to 

 work the iron while it is hot, with a low tem- 

 perature for finishing ; but that the severest 

 microscopical test is obtained with cold-sawed 

 rails. 



An important paper on the metallurgy of the 

 cupola was read by H. E. Field before the Amer- 

 ican Foundrymen's Association, and is published 

 in the Age of Steel for July 5, 1902. 



Rails that had failed in service which were ex- 

 amined by R. Job were found to be character- 

 ized by a coarse, regular granular structure and 

 by containing an excess of foreign matters, such 

 as oxids, slags, and occluded gases; while rails 

 of the same general composition which had 

 proved satisfactory in service were relatively free 

 from foreign matter and gas, and presented a 

 generally fine granular form, interlocking and 

 broken up. 



An invention which has been tested in Chicago 

 for applying electricity to the cutting of iron or 

 steel includes a carbon attached to a wooden 

 handle by means of a metal clamp ; to this clamp 

 a wire is fixed, which is connected at the other 

 end with the object to be operated upon. As the 

 carbon is moved along the object it cuts its way 

 through even such metals as Bessemer or chrome 

 steel. In the case of the Chicago experiment, a 

 wide space was cut away in the plate of a large 

 boiler foundation which was to be removed, at 

 the rate of about one foot every five minutes. 



From the investigations of the sulfur contents of 

 slags, described by Baron Juptner at the meeting 

 of the Iron and Steel Institute, the follo\ying con- 

 clusions were drawn: If diiring metallurgical proc- 

 esses a state of equilibrium is established between 

 the slag and the contiguous metallurgical product 

 under treatment, the sulfur distributes itself be- 

 tween the two in a constant ratio the coefficient 

 of distribution the value of which is dependent 

 on the composition of the two phases under con- 

 sideration and the temperature. In general the 

 value of the coefficient of distribution increases 

 with the basicity of the slags. It increases also 

 apparently Avith the proportion of lime and man- 

 ganous oxid, and probably also with that of fer- 



