134 MILITARY SCIENCES. 



have the metal run into the mould at the side, so that the core be not dis- 

 turbed in its position by the metal falling perpendicularly upon it. Fig. 33 

 shows the upper view of the lower mould-box : a is the pattern ; g, the 

 thumb-screw nut of the screw which holds the pattern of the fuse-hole plug, 

 and which is loosened in withdrawing the patterns ; A is the sand bed of 

 the mould ; m, hooks for lifting the mould-box. The core is formed either 

 of sand or loam. PL 39, fig. 34, shows the perpendicular section of both 

 mould-boxes, with the loam-core in place, for a shell or bomb; fig. 36 is the 

 side view of the two mould-boxes ; fig. 35, the upper view of the finished 

 mould ; fig. 37, under view of the same : A is the upper, B the lower mould- 

 box ; a is the cavity which is to be filled with metal ; 6, the jet hole ; c are 

 key-bolts, to hold the mould-boxes ; e, air- vents ; /, key-bolts, to hold the 

 core-spindle, k, immovable in the bridge n ; g, ears set in the mould, for the 

 shell-hooks ; the holes for the ears are made by small clay cylinders inserted 

 in the mould. The ears are of wrought iron, and the ends reach into the 

 internal cavity, where they are afterwards imbedded in the metal, k, core- 

 spindle of wood or sheet iron and covered with a thin coat of loam, bored 

 diagonally through lengthwise, to permit the gas to escape from the core. 

 The core, i, consists of spun hay, which is wound firmly upon the spindle, 

 and covered with several coats of loam, then turned at the core bench 

 according to the pattern, and well dried ; /, bolt to secure the perfectly 

 accurate placing of the halves of the mould ; m, hooks for handling. The 

 sand-cores, which are better and now more used than the loam cores, are 

 struck in a mould with three parts. Fig. 40 shows one of the two like parts 

 a, which, united by the third, the cap/> (^^.41), are closed, and their inter- 

 nal cavity becomes exactly the size of the core ; o is the handle for taking 

 off the cap. Fig. 38 is a view, fig. 39 a section of a core-spindle : h, the 

 shaft ; /, the hole for the fixing-key ; k, the holes bored for air- vents. To 

 strike the sand-core, the stuff for which consists of a mixture of sand, loam, 

 and powdered cinders or coke, the two parts a (fig. 40) are brought into a 

 moulding-bench {fig. 42, upper view, fig. 43, longitudinal profile, fig. 44, 

 half cross-section). Upon the mould box r the core-spindle k is made fast 

 by the key/, the half-moulds, a, set on and pressed together by means of the 

 cheeks C C and the screws D D, then a couple of wires, e, are laid in to form 

 the air vents, and the core rammed solid with the mould-stuff; the cap p, set 

 on by the handle o, and struck to make the foot of the core firm. When now 

 the mould is opened the core can be taken out, dried, and set in the finished 

 mould. For fire-bombs, which have three fire-holes, a (fig. 45, section, ^g*. 

 46, view of a fire-bomb), the sockets for the clay cylinders, which are to 

 form the core of these holes, are formed at the same time with the mould. 

 Fig. 47 shows the two mould-boxes, A and B, for fire-bombs, with the pat- 

 tern placed in them ; fig. 48, the upper view of the lower mould-box A ; 

 fig. 49, the vertical sections of both mould-boxes, with the core in its place ; 

 fig. 50, the lower mould-box, with the section of the core ; a is the pattern, 

 having beneath the spindle q, by which the fuse-hole is formed ; in the mid- 

 dle is the projection, r, by which the bed for the hollow clay cylinder, s, is 

 formed, running a piece into the mould sand, and reaching to the core ; i is 

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