130 MILITARY SCIENCES. 



collars, m m, and held in its place by the oblique tie, /. The frame, h, has 

 numerous holes, ii, by which the mould board can be placed as desired, 

 and the oblique tie has slits, s s, corresponding to the slit, k^, in the mould 

 board, so that it may be set by means of the screw, t. The height at which 

 the frame, h, is placed is regulated by a collar at o. The screws, n, serve 

 to fix it. The pattern being completed upon this turning machine, trun- 

 nions and dolphins are put on, and the mould itself is made. During the 

 process a gentle coal fire is kept constantly burning inside the cupoja. PI. 

 S9, fig. 28, shows the completed mould, the different layers being taken off 

 in parts to exhibit the structure. Beneath the mould proper, z, we see an 

 addition ; this is the dead-head, and gives afterwards in the casting an over- 

 plus of metal, by means of which that contained in the mould is rendered 

 more compact ; in the boring process it is cut off. At the top we see 

 another addition; this is designed to hold the mortar, ly, in the turning 

 machine, and is likewise cut off. As to the layers in the mould, there 

 comes first a coat of fine loam paste, p, then three coarser layers of mould 

 loam, y, then an armature of iron bands perpendicular and horizontal, Wy 

 and finally the outermost layer of coarse mould loam, v. When the mould is 

 finished and dry the pattern is broken to pieces within it and taken out by 

 fragments, the trunnions and dolphins melted out, and the mould is then 

 ready for casting. 



b. Dry Sand Moulding. With very different celerity and exactness 

 goes on the modern process of dry sand moulding, first introduced by Gene- 

 ral Guillemin at Li^ge. In this a pattern of metal is employed, which is 

 divided in such a manner that the different pieces which compose it can be 

 easily taken out from the finished mould. Fig. 5 shows the section of a 

 moulded 6-pounder gun, and it is perceived that the pattern consists : 1, of 

 a solid, conical piece of wood, h, mounted with rings, ii, and furnished with 

 a ring-bolt', k ; 2, of a pattern for the muzzle m n^ with the muzzle mouldings 

 m and /, which can be taken off; 3, of a pattern, o, for the chase with its 

 movable rings and the draw-hooks, xx; 4, of a pattern q for the second 

 reinforce, with the trunnion patterns jojf? screwed on : 5, of a pattern for the 

 breech, s t, with the base mouldings and the draw-hooks, z z ; 6, of a pattern 

 for the cascable, u, which can be united with the pattern 7, for the knob of 

 the cascable and the turning-head v, by means of a screw-bolt, w. To each 

 of these seven patterns belongs a mould-box also, although single pieces of 

 the patterns project into other mould-boxes. These mould-boxes are seen 

 in fig. 4, under the letters A, B, C, D, E, F, G, H ; the mould-box D has besides 

 the side boxes E E' for the trunnions. The mould-boxes consist always of 

 two exactly equal shells, which are of greater diameter than the pattern by 

 the sand thickness of the mould, and are provided with longitudinal and 

 cross flanges, to connect the shells with each other and the mould-boxes 

 together into a whole, by means of the key-bolts, a db. Each mould-box 

 has handles,//, for lifting it by the crane. Internally the walls of the mould- 

 boxes are provided, according to fig. 7, with depressions, in order that the 

 mould-stuff, when rammed in, may hold faster. The moulding process is as 

 follows : First, the box G is placed with the broad side upon a bed, which 

 606 



