490 Chronicles of Science. LJuly, 



ture. The first condition requiring dull and heavy blows — the 

 second demanding sharp and violent ones. It is most probable that 

 vibratory action of any kind, long continued, is liable to change the 

 structure of metals ; at the same time none of the experiments which 

 have been made appear to have been sufficiently conclusive, and all 

 the results obtained can be explained, as Brunei explained them, by 

 the nature of the breaking blow. Seeing the important uses to which 

 iron and steel are applied, it is surely desirable to determine this 

 problem beyond all doubt. 



We are desirous of recording every step, which may ever promise 

 to be an advance in any of our Metallurgical operations. The 

 Messrs. Woodwards, of Ancoats, have been making experiments on 

 the smelting of pig-iron in the ordinary cupola, through the agency 

 of steam. The great object being to get rid of the fan and its me- 

 chanical accessories. As we understand the arrangements, it appears 

 to be the use, in a modified form, of the steam jet, as used by Golds- 

 worthy Gurney, for ventilation, and as employed in our locomotive 

 engines. At the upper part qf the cupola, immediately above the 

 part where the charge is put in, a steam pipe 1^ inch bore is inserted 

 into a wrought-iron chimney equal in length to the depth of the cupola 

 below. Such is the arrangement. The fire is lighted, and the charge 

 made in the usual manner. The door of the charging hole is then 

 closed, and the steam is turned on. The rapid current of steam 

 rushing through the chimney carries the air with it, causing a mo- 

 mentary partial vacuum immediately above the fuel and the metal. 

 The only place through which air can enter is below — and there 

 through ten openings it rushes in with a velocity which is regulated 

 by the force of the steam jet. This arrangement is said to secure a 

 general and uniform heat throughout the furnace, and to produce 

 more perfect combustions of the fuel. For smelting a ton of pig-iron 

 it is stated that little more than 1 cwt. of coke is required, while the 

 bringing down of the molten metal is effected more speedily. 



A further improvement in this apparatus is in progress. The 

 upper portion of the cupola will be surrounded by a boiler, from 

 which steam will be supplied to the fire. Thus, after the furnace 

 has fairly started, it will, by its own heat, generate the steam by 

 which the work is to be performed. 



Some time since, our newspapers informed us that a wonderful 

 iron letter was sent to this country from Pittsburgh. This was a 

 sheet of iron so thin, that it required 1,000 of such sheets to make 

 one inch in thickness, the dimensions being 8 inches by 5^ inches, or 

 a surface of 44 inches, and weighing 69 grains. Soon after, there 

 was produced, at the Marshfield Iron Works, Llanelly, a sheet of the 

 same size which weighed only 48 grains. This was soon followed by 

 a sheet of iron, made at the Hope Works, in Staffordshire, with a 

 surface of 118 inches, which weighed but 89 grains. This, reduced 

 to the American standard of 44 inches, gives about 33 grains. While 

 Messrs. E. Williams and Company made a similar sheet weighing but 

 31 grains, the Marshfield Company, desiring not to be outdone, soon 

 succeeded in making a sheet of 44 inches, which weighed only 23£ 



