84 ANNUAL OF SCIENTIFIC DISCOVERT. 



est possible heat, so as to economize iron and fuel, but regardless 

 of insurin;:: a perfect weld ; and hence, lamination and failure 

 rapidly follow after a few months' wear. So much for the dura- 

 bility of the ordinary Aiuerican rail. Now as regards its safety: 

 Just as the presence of sulpluir in iron renders the metal reil- 

 short, as previously explained, so the presence of phosphorus 

 causes the iron to become brittle and cold-short. It is, there- 

 fore, of great importance, in producing a good and serviceable 

 rail from such inferior mati^'ials, that the liard, cold-short iron 

 should form the top, or WQ;iring portion, of the rail, while the red- 

 short, or tough and librous iron, should be used for the llange; as 

 the character of the ores distributed through the principal rail- 

 making districts of this country is such that cold-short iron is pro- 

 duced in one district, and red-short in another, it is necessary that 

 the two kinds of metal should be brouo:ht ton^ether, and used in 

 association, as previously described, if they are to produce a truly 

 serviceable rail. But as the cost of transport from one district to 

 another becomes an important item, it will evidently be to the 

 interest of the manufacturer, if not restricted, to use the unmixed 

 home material, whether cold-short or red-short. Under such cir- 

 cumstances, a rail is produced either too brittle, and therefore 

 dangerous, or too pliable, and therefore less capable of enduring 

 the wear and tear of traflic. There are, perhaps, few countries 

 that of late have suffered more from fracture of rails than Amer- 

 ica. This has led some railway administrations, in that country, 

 to require that the rails should be tested ; but when'as they were 

 formerly too careless in this respect, they now seem inclined to 

 err on the other side by specifying too severe a test for the rail, 

 and thus compelling the maker to use too soft an iron. For in- 

 stance, it is otten required that a weight of one ton shouKl fall 

 upon the rail from a height of 10 feet, when half such a test 

 would insure breakage of the rail in any climate. I may now 

 brieth' refer to the method adopted in making rails for tiie Eng- 

 lish and Continental companies. There are but few of these 

 railway administrations which, when inviting tenders for a supply 

 of rail, do not specify distinctly that the top slab, constituting the 

 wearing surface of the rail, must be of the very best material, 

 and at least two inches in thii'kness, thus giving a wearing sur- 

 face of one-half inch in the head of the rail; and, further, tiiat 

 the rail should stand a test half as severe as that previously men- 

 tioned as ap|)lied to Ameriean rails. From what has now been 

 advanced respecting the different modes of mannfaetui'ing Amer- 

 ican an<l Euro})ean rails, 1 leave the respective American railway 

 administrations to judge whether they would not best consult their 

 own interests by adopting the English and Continental system of 

 well-delined specilieation and tests, instead of looking merely to 

 the small saving effected by always accepting the lowest tender. — 

 E." — Journal of the Franklin Iiistilute^ March, 18G9. 



