The top board is afterwards taken off, the clean surface of moist sand then exposed, is well dustsd over with red brick-dust crushed fine and contained in a linen bag: the mouth of the bag is held in the right hand, and the bottom corner in the left, and both hands are shaken up and down together, to scatter the dry powder uniformly over the flask; a part of the loose powder is removed with the hand-bellows, and the bottom half of the mould is then ready for receiving the patterns.

The models are next arranged upon the face of the sand at 4, so as to leave space enough to prevent the parts breaking one into the other, and also for the passages by which the metal is to be introduced, and the air allowed to escape. When there are only two or three pieces to be cast, a separate runner is often made to each of them from one of the holes in the end of the flask; when several small patterns are to be moulded, they are arranged on both sides a central runner, or ridge, from which small passages lead into every section of the mould. The whole mass when poured has been compared to a great fern leaf with its leaflets, and is usually called a spray.

Those patterns which are cylindrical or thick, are partly sunk in the sand, by scraping out hollow recesses with the bowl of an old copper spoon, and knocking the model into the sand with a mallet; afterwards the general surface is repaired to agreement with the diametrical line of the model, or its largest section, as the case may be, by means of a knife or a little piece of sheet steel, something like the worn-out blade of a dessert-knife bent up a little at the end, or else with wry small trowels.

After the sand is made good to the edges of the patterns the brick-dust is again shaken over them, so that the patterns may receive a slight share as well as the general surface of the sand. The upper part of the flask 2, 3, is then fitted to the lower, or 4, 5, by the pins, and this half likewise is made up; first a little strong sand is sifted in, it is then filled up from the trough, rammed down, and struck off as before, the dry powder serving to prevent the two halves from sticking together.

In order to open the mould for the extraction of the models, a board is placed on the top of flask 2, 3, and struck smartly at different parts with the mallet, the tool is then laid aside, and the upper part of the flask and its board are lifted up very gently and quite level, after which it is inverted on its board, and now each of the inner faces of the mould is exposed. Should it happen that any considerable portion of the mould, say a part as large as a shilling, is broken down in one piece, the cuvity is moistened with the end of the knife, the mould is again carefully closed, and lightly struck before the removal of the patterns; it is probable on the second lifting such piece will be picked up.

The breaks are carefully repaired before the extraction of the patterns, to effect which they are driven slightly sideways with blows of the mallet given on a short wire or punch, so as to loosen them by enlarging the space around them; the patterns are then lifted out very carefully with the finger-nails, or sometimes a pointed wire is driven a little way into the pattern to serve as a handle to lift it by: * this process requires some delicacy not to tear away the sand, which accident must be carefully repaired, sometimes by replacing the loose pieces, at other times with a little new sand picked out of any unused part of the mould.

Should the flask only contain one or two objects, the ingate or runner is now scooped out of the sand, so as to lead from the object to the pouring hole, and when several objects are contained.

* A steel wire, pointed and hardened, is convenient as a picker out, and when fixed in the pattern and struck sideways it serves as a loosening bar likewise.

a large central channel, and lesser passages sideways, are made as before mentioned. The entrance round about the pouring-hole is smoothed and compressed with the thumb that it may not break down when the metal is poured, and all the loose sand is carefully blown out of the mould, both parts of which may be placed edgeways for the more convenient application of the bellows if necessary.

The succeeding processes are to dust the faces of both halves of the mould with meal dust or waste flour, as explained with regard to the brick dust, and to replace the mould and boards: the whole of them are then carried to the spill-trough, upon the edge of which they are rested whilst the one board is placed exactly level with the end of the flask, but the board on the side from which the crucible will be poured, is placed about two inches below, as in fig. 161, p. 326, and the hand-screws are fixed on as shown. The mould is now held mouth downwards, that any sand loosened in the screwing down may be allowed to fall out, and the flask, according to its size, is supported either on the ground or on the surface of the trough by aid of a little bar resting against the clamp: it is now quite ready to be filled, the particulars of which process will be described when the remarks on moulding are concluded.

In works that require the first side or 3, 4, to be cut away for embedding the models, it is usual when the second part or 2, 3, has been made, to destroy the first or false side, (which is only hastily made,) and to repeat it in a more careful manner by inverting the lower flask upon 2, 3, proceeding in all other respects as before, by which means a much more accurate and sound mould is produced.

When many copies of the same patterns are required, an odd side is prepared, that is, a flask is chosen to which there are two bottom sides, 4, 5. One of these latter is very carefully arranged with all the patterns, but which are only embedded barely half way, so that when 2, 3, is filled and both are turned over, the whole of the patterns are left in the new side; a second side, 4, 5, is moulded to serve for receiving the metal, as the mould is destroyed every time the metal is poured in. By this plan the trouble of re-arranging the patterns for every separate mould is saved, as they are merely replaced in the odd side, and the routine of forming the two working sides is repeated.