TRANSACTIONS OF THE SECTIONS. 167 



scribed at Cheltenham, the author proceeded to show how the disadvantages of 

 the old fixed converting- vessel were remedied and other improvements introduced. 

 Many forms of converting- vessels were tried on the large scale before this desirable 

 object was attained. In some of them the lining was too easily broken down by 

 the violent motion of so heavy a fluid as iron ; in some of the forms tried the an- 

 gles allowed the metal to solidify in them, and so clog up the vessel ; in others, the 

 mouth of the vessel being too small, caused the metal to be thrown out by the force 

 of the escaping blast. It was also found that if the mouth was too large the heat 

 escaped, so as to cause part of the converted metal to solidify in the vessel ; the re- 

 lative height and diameter of the vessel was also found to produce important dif- 

 ferences in the working of the process ; finally, and after many long and expensive 

 trials, the form of vessel shown in a diagram was adopted. This vessel is made in 

 two parts, so as to admit easily of its being lined up with a pulverized siliceous 

 stone, known as ' ganister,' which so resists the action of the heat and slags as to 

 last for fully 100 consecutive charges of steel before it is worn out. Its form is that 

 of the arch in every position which prevents the lining from falling down by its 

 own weight. There are no angles in which the splashes of metal can solidify and 

 accumulate. Its mouth directs the flame and sparks away from the workman, and 

 from the moulds and other apparatus ; while the throat of the vessel, and the posi- 

 tion of the mouth, almost entirely prevent the throwing out of the metal. The 

 vessel is mounted on trunnions supported on stout pedestals, so that a semirotary 

 motion may be communicated to it at pleasure. The tuyeres are placed at the bot- 

 tom of the vessels, so as to force the air vertically upward through the metal, as 

 shown, without coming in contact with the sides of the vessel. When the crude 

 metal is to be run into the vessel, it is tinned on its axis nearly into the position 

 shown, the mouth being a little higher up ; a gutter will then conduct the crude 

 cast iron from the melting-furnace into it. It is not necessary to turn on the 

 blast until the whole of the metal is run in, because the tuyeres occupy a position 

 above the level of it. As soon as the air is admitted through the tuyeres, the 

 vessel is turned into the position shown, when its decarbonization immediately com- 

 mences. As soon as this is effected, as much molten pig iron made from spathose 

 iron ore is added to it as will restore the quantity of carbon necessary to produce 

 the desired quality of steel, which is then rim into the casting ladle in the manner 

 shown, and from whence it is transferred to a series of iron moulds ranged in a 

 semicircular pit, each mould being placed within the sweep of the casting-crane ; 

 the filling of these moulds is regulated by a cone valve made of fireclay and fitted 

 in the bottom of the casting-ladle, so as to be opened or shut at pleasure by means 

 of a handle on the outside of the ladle. 



It will be readily understood that in the fixed vessel first described any giving 

 way of a fireclay tuyere would stop the process and cause much inconvenience ; 

 but with the moveable vessel it is not so, for at any moment of time during the 

 process the vessel may be turned on its axis and the tuyeres raised above the level 

 of the metal ; the blast may then be turned off, the tuyere box opened, and the 

 faulty tuyere stopped up or removed, after which the process niay be again resumed. 

 The movement of the vessel on its axis, the rise and fall of the casting-crane, and 

 the other cranes employed for removing ingots from the casting-pit, are all effected 

 by a simple hydraulic apparatus, so that the whole process is under the perfect con- 

 trol of a single operator, placed far away from the heat and showers of splashes that 

 accompany the process. 



Up to this period the mauufacture of cast steel by the old as well as the new 

 process is still so far imperfect that steel of the highest quality cannot be made from 

 inferior iron. In the old Sheffield process the original quality of the Swedish char- 

 coal iron employed governs the quality of the cast steel made ; consequently £36 

 per ton is freely given for the high class Danamora iron, while other brands of 

 Swedish charcoal iron may be bought for £15. In either case these are expensive 

 raw materials for the cast-steel maker. 



In 1839 the trade of Sheffield received an enormous impulse from the invention 

 of Josiah Marshall Heath, who patented in this country the employment of metallic 

 manganese, or, as he called it, 'carburet of manganese.' The addition of a small 



