PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 453 



ing steel into forms, so that but little work of the hammer should 

 be required to make a finished article— in making plough-shares, 

 for instance. Is the steel of good quality as to hardness, elasti- 

 city, &c.? 



Mr. Selleck. — The steel plough-shares so made are sold nearly 

 at the usual rate of conuiion plongli-shares. They possess the 

 important quality that the soil does not stick to them. Their 

 durability has not been fairly tested as yet, for the works were 

 only commenced last spring. But, the strength of tlie shares 

 has been tried by their resistance to fracture, and I have seen 

 them, after being broken, drawn out into perfectly malleable 

 steel, from which razors were made. 



Mr. Fisher. — What should you say of making the crank-pin of 

 a locomotive in that way, where strength is of the first consider- 

 ation ? 



Mr. Selleck. — I should not recommend it, because I think there 

 is a much better way to make them, namely, of Franklinite, in 

 which I had a good deal of experience. There is a great deal 

 of old cast iron, such as grate bars, which is considered good for 

 nothing; but I find that mixing a little Franklinite with it, it 

 will run just like water, and give a valuable product. 



The Chairman. — What is the comparative value of the Frank- 

 linite as a residuum and of the Franklinite ore as taken from the 

 mines? 



Mr. Selleck. — If you use the ore without extracting the zinc, 

 you cannot use more than five per cent, to any advantage ; but 

 using the residuum after the zinc is extracted, you may use 25 

 per cent., and will get a better result. 



Col. Curtis. — I have known ten or fifteen per cent, of the ore 

 to be used in the blast furnace. The trouble is that it is neces- 

 sary to make some provision for driving the zinc out of the 

 furnace. But it may be driven out, and may be collected again. 

 Persons running blast furnaces sometimes object to paying the 

 price asked for Franklinite, for the reason that the yield of iron 

 is less than from the magnetic iron ore. Suppose an iron furnace 

 consuming about ten thousand tons of magnetic iron ore, and 

 that it is proposed to add two thousand tons of Franklinite, it 

 is admitted that it will increase the value of the iron, and out 

 of the two thousand tons of ore will be obtained about eight 

 hundred tons of iron, worth the cost of the ore. But hitherto 

 they have permitted the zinc to escape, and by saving that they 



