90 ANNUAL OF SCIENTIFIC DISCOVERY. 



centre, frequently to such an extent as to permit the passage of air or 

 water from end to end. This evil Mr. N. corrects by using a wedge- 

 shaped, or V anvil, between the jaws of which the work to be ham- 

 mered is placed. In this case, instead of a tendency to spread, so 

 as to render the central portion of the metal less compact and solid, we 

 have exactly the opposite effect, besides which the article is more 

 easily kept under the hammer, and the scales or impurities which fall 

 from the hot iron fall down into the apex of the V out of the way, thus 

 removing the blemish and roughness which is caused by the scales 

 collecting on the face of the anvil and being beaten into the surface of 

 the metal. The compressing effect of the blows, too, is so much en- 

 hanced that as much can be hammered out at one " heat " by the new 

 anvil as in three " heats " by the common one. The angle of 80 is 

 most generally suitable for the inclination of the sides of the V ; the 

 edges should be well rounded off and the surface of the V sides curved 

 in the direction of the axis of the work, to the extent of one eighth of 

 an inch in twelve inches, so as to be " proud " in the centre, and thus 

 facilitate the extension (axis-ways) of the work. One anvil will ac- 

 commodate forgings of all diameters, which are not so large as to rest 

 on the upper corners, nor so small as to touch the apex. These anvils 

 have been very extensively introduced. 



Mr. Nasmyth also described an improvement in welding. He com- 

 menced by showing that the frequent defect in welding arises from the 

 interposing of scoriae or " cinder " between the welded surfaces, which 

 prevent the two surfaces from being brought in contact at all points. 

 The " slabs " produced under the action of a forge-hammer and anvil 

 usually have some portions of their surfaces slightly concave, and the 

 concavity is ordinarily such that the parts which come into contact 

 first are the exterior edges. The blows of the hammer weld the parts 

 in natural contact, and in a greater or less degree expel the scoriae, 

 which will escape as long as there is a passage out, but if, as has been 

 said is generally the case, the exterior portion of the surfaces of the 

 slabs is the first welded, the scoria must remain, and no amount of 

 hammering can remove them, and thus we have an unsound welding. 

 The remedy for this great evil is a very simple one. It is only neces- 

 sary so to form the surfaces to be welded that a free exit may be pre- 

 served to the last for the scoria?, and this is done by making one of the 

 surfaces slightly convex, so that the welding begins at the centre and 

 proceeds outwards, thus forcing out all the scorire, and allowing com- 

 plete contact. Civil Engineer and Architect's Journal, Sept. 



IMPROVEMENT IN THE MANUFACTURE OF IRON. 



THE Jersey man describes a new process for making iron, the inven- 

 tion of Mr. A. Dickson, of Newark. The fire is placed at the end, 

 under a horizontal bed of fire-brick some twelve or fifteen feet in 

 length, the fire passing through to the other extremity. In the centre 

 and over the bed is erected a double cylinder, which is filled with 

 crushed ore and pulverized anthracite coal. The intense flame sur- 

 rounds the cylinders, and also passes through the centre by the inner 



