PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 413 



STEEL AND ITS USES. 



Mr. Fisher,. — Semi-steel was claimed to be cheaper than 

 iron for the manufacture of ships, and for some other pur- 

 poses, costing but little more per pound, comparatively, and 

 being stronger. The Bessemer steel is also advertised at a cheap 

 rate. The inventor states that he can manufacture it in masses 

 of twenty tons ; and that he can make steel plates of enormous 

 length and breadth, at as cheap a rate as smaller plates. Plitherto 

 in the manufacture of iron plates the cost increases with the size. 



When small plates are ordered, Bessemer cuts them from the 

 large plates. Thirty years ago the wear of the rail upon rail- 

 roads was supposed to be too slight to be taken into account. 

 Now, rails are sometimes used up in a single season. The rails 

 may be made of cheap steel, and will be more durable. And 

 such steel may be used for axles, for wheels, and for many parts 

 of cars, arid locomotives especially, instead of iron. Thus, loco- 

 motives may be made a great deal lighter. The durability of 

 railway machinery may therefore be very much increased, and 

 the cost of railway transportation proportionally lessened. This 

 lightening of the locomotives will obviate one great objection to 

 their use upon common roads. Pavements may probably be made 

 cheaper of cast iron ; but trams ,may be made cheaper of steel 

 than iron plates, and can be protected against rust. 



Mr. Dibben. — Mr. Bessemer has lately adopted a process some- 

 what different from that he has hitherto used, making his metal 

 into iron and mixing it again with a certain quantity of cast iron, 

 so as to give it a more uniform quality than he could obtain by 

 his previous process. Puddled steel is merely high iron, iron 

 with a little extra carbon in it, and I think too much merit is 

 ascribed to it. When put into a ship it is inferior to common 

 iron for a corrosion of the metal takes place in spots, produced, 

 as some suppose, by electro-magnetic action, one part of the plate 

 becoming positive and another negative. 



Mr. Stetson said that the manufacture of cheap steel is yet in 

 an experimental condition, being regulated by empirical rules. 

 Some of the facts are known with scientific certainty j but the 

 intensity of the heat and attendant difficulties prevent such an 

 investigation of all the facts as may be made ii^a chemical experi- 

 ment. When we speak of good iron, reference must be had to the 

 use to which it is to be applied. For instance, a stove casting 

 requires an iron that is very liquid when melted 5 but, for larger 



