498 TRANSACTIONS OF THE 



64,000 ; of cast steel, 150,000, The weight of iron in the tuhes of the 

 greatest bridge in the worlJ, the Victoria, in Canada, is 10,000 tons. It 

 might have been built with 3,000 tons of steel, and been equally strong, if 

 not stronger. Locomotive engines might be constructed of steel half the 

 weight of iron, with return tubes in the boiler, so that the heat might 

 traverse twice its length, thus much increasing the evaporative power, add- 

 ing to the speed, with half the wear and tear upon the rails. This im- 

 provement, together with the use of coal instead of wood, would save ono 

 hundred and forty thousand dollars per annum upon every seventy-five 

 locomotive engines running in the United States. And if the cars were 

 made of steel strips, instead of wood, they would strike each other, in 

 case of collision, and spring back, instead of rushing into each other and 

 breaking up as they do now, to the imminent danger of life and I'luxh. If 

 high tensile strength is desired in iron, you may continue almost indefinitely 

 to increase it by remelting the pig. For example, if kept twenty minutes 

 in fusion, it will bear a strain of twenty thousand pounds to the square 

 inch ; if two and a half hours, twenty-five thousand pounds ; five hours, 

 thirty thousand pounds; seven hours, thirty-seven thousand pounds, &c. 

 The tensile strength would be further increased by very slow cooling in 

 each instance. The American government deserves greast credit for the 

 able experiments they have caused to be made on the tensile strength and 

 specific gravity of metal in cast iron ordnance. Whenever the strength fell 

 below 20,000 pounds to the square inch, the quality was pronounced bad. 

 We took these important steps before alt other governments, and the con- 

 sequence is, they have been compelled to award us the initiative, and copy 

 our example. The xVnserican government was the first also to investigate 

 the quality of coal for a steam navy, and the results were everywhere pub- 

 lished before the English made a similar inrjuiry. The Americans were 

 the first to produce refined steel directly from the ore in the bloomery 

 forges. The Abbe Pauvert has invented a plan of producing steel of a 

 very fine quality from puddled iron and scraps in any state, at a wonderful 

 reduction of price, without the slightest change in the arrangements of the 

 melting furnace, it being efi"ected by chemical ingredients and elastic 

 agency. Steel fabricated by the old process from Swedish iron, costs eighty 

 dollars per ton ; whereas, by the Abbe's process it may be procured for 

 twenty-five dollars from refuse iron, without loss of material, as one ton 

 of iron yields one tcjn of steel. Electricity assists him. 



Pig iron, during its conversion into wrought iron, undergoes chemical 

 changes. Carbon is increased during the earlier stages of tlie process, 

 while silicon diminishes, and carbon again decreases when agglomeration 

 takes place. The following composition w.ill prevent the oxydation of 

 steel or iron, by entering the pores, without in the least injuring the out- 

 ward appearance: Silver filings, four parts; yellow tincal, 12 ; bismuth 

 purified, 12 ; zinc purified, 12 ; Malacca tin, pure, 120 ; regulus of anti- 

 mony, 11; nitre, 11 ; salt of pcrsecaria, 1. 



There is a company in this city who produce steel of every quality and 



