MECHANICS AXD USEFUL ARTS. 43 



more, if not less, for the iron than for the stone paving, and the proba- 

 ble increased endurance, apart from its other tested advantages, will, 

 we should think, throw the preponderance of economy vastly into the 

 iron scale. Glasgow Journal. 



ON THE LAMINATION OF IRON. 



WE derive the following remarks, in reference to the lamination of 

 iron, especially when used for railroad bars, from an article by H. L. 

 Damsel, Esq., in the Journal of the Franklin Institute for August : 



Various attempts have been made to remedy the tendency of best 

 iron to laminate. An ingenious apparatus has been patented in this 

 country, and also in England, for twisting the rail bar, while it is in the 

 course "of manufacturing. By means of powerful machinery, the bar 

 is twisted while in its rough .state, until the fibres of metal encircle 

 the rail, instead of lying in a direction parallel with its axis. But it 

 is found that the twisting of the bar alone is insufficient to retard the 

 laminating process, while the fibrous character of the metal still exists. 



An English manufacturer has patented a process for manufacturing 

 what appears to be a near approach to an anti-laminating rail. His 

 plan is to construct the upper or Avearing part of the rail from puddled 

 charcoal iron in the un wrought state, and the lower part from the iron 

 ordinarily used in manufacturing rails. This arrangement materially 

 reduces the formation of fibre ; yet the high price at which these rails 

 have been sold in England, has hitherto limited their employment to a 

 few isolated experiments on some of the leading railroads hi Great 

 Britain. 



To discover means whereby wrought rails might be rolled from com- 

 mon metal, and yet be free from the laminated structure attendant on 

 its employment, experimental trials were made with rails rolled from 

 variously constructed piles, built up of common puddled iron, with and 

 without the admixture of superior qualities. This was done with the 

 view of ascertaining if the present system of piling could not be advan- 

 tageously altered for one which, with little or no additional expense in 

 the manufacturing over that now incurred, would result in the produc- 

 tion of a perfectly non-laminating rail. The object aimed at, therefore, 

 was one which, if attained, would be of incalculable benefit to railroad 

 companies. The plan usually adopted is to arrange the bars, whether 

 these are of milled or puddled iron, side by side, and one on the other, 

 till a pile is built of the required dimensions. By thus arranging them, 

 the grain or fibre of all the bars runs in the same direction longitu- 

 dinally. This parallelism is maintained in the subsequent process of 

 rolling, when the pile is distended from its original length of about three 

 feet, into a finished rail of from 24 to 20 feet long, but is reduced laterally 

 and vertically from seven inches wide and nine inches high, equal to 63 

 sectional inches, to a bar, averaging, perhaps, six square inches. The 

 fibres of the metal are thus distended longitudinally to nine times their 

 original length, and, to meet this elongation, they are compressed into 

 one ninth of their original sectional area. The fibrous character of 

 the metal continues and is multiplied at each successive rolling, until. 



