80 ANNUAL OF SCIENTIFIC DISCOVERY. 



by the amount of metal, the pipe being made of any degree of 

 thickness required. 



The effect within the mould is quite singular, and very distinctly 

 perceived during the operation. As the revolution commences, noth- 

 ing is to be seen within but a confused mass of molten metal appar- 

 ently occupying the whole of the interior; suddenly, but noiselessly, 

 with a discharge of flame, the metal has taken its place at the sur- 

 face of the mould, is revolving truly with it, and in the twinkling of 

 an eye the perfect tube is seen within. In a few seconds, the revolu- 

 tion ceases, the mould is separated, the upper half being hoisted off, 

 and the pipe removed. There is no adhesion, the pipe in the instant 

 of cooling undergoing contraction sufficient to obviate this, were 

 there no artificial protection against it. The time occupied from the 

 tapping of the furnace to the lifting the perfect pipe from the mould 

 was precisely two minutes. And it is obvious that, with a range of 

 two or three moulds in operation, pipe could be turned out as rapidly 

 as the metal could be drawn from the furnace. 



But the invention will not be confined to the mere casting of iron 

 pipe. It is evidently applicable in various departments throughout 

 the whole range of the mechanic arts. It is not limited in its effects 

 either, as we understand it, to a mere smooth surface, but while re- 

 taining its circular form it will adapt itself to every variety of external 

 shape and ornament. 



ON THE MANUFACTURE OF THE FINER IRONS AND STEEL. 



MR. GREENER has read a paper before the British Association, 

 " On the Manufacture of the Finer Irons and Steel, as applied to 

 Gun-Barrels and Swords." The first innovation on the old principle 

 of manufacturing gun-barrels entirely from old horse-nail stubs was 

 caused by the introduction of the so-called Damascus iron, which is 

 formed of alternate layers of steel and iron, fagoted, drawn down 

 into rods, then tortuously twisted, and when welded into barrels, it 

 forms the Damascus barrel. The success of this experiment, both in 

 beauty and strength, was so great, as to be under-estimated at 50 per 

 cent., as compared with the strength of stub-twist iron. The next 

 experiment was to blend more intimately steel with horse-nail stubs, 

 in proportion of one to two of the latter. The next and most im- 

 portant improvement was in the manufacture of gun-barrels from 

 scrap-steel entirely, and for this purpose old coach-wheels were gen- 

 erally in request. By clipping these into pieces, cleansing them, and 

 welding in an air-furnace, a metal is produced, which surpasses in 

 tenacity, tenuity, and density any fibrous metal ever before produced. 

 Its tenacity, when subjected to tension in a chain-testing machine, is 

 as 8 to 2 over that of the old stub-twist mixture. No gunpowder 

 yet tried has the power to burst barrels made from it, when properly 

 manufactured. These experiments have induced others on a more 

 extensive scale ; to effect this, ingots of cast-steel were taken from 

 the mill, made to No. 3 in the scale of carbonization. These, after 

 rolling into flat bars, were clipped into small pieces, immediately 



