These are of several kinds, the best known being the Charnley Forest,. Turkey, Arkansas, and Washita brands. They are sold in pieces of convenient size at about Is. 6d. to 2s. a lb., and smaller slips for gouges at 4s. a lb. They can be procured ready cased, but if bought without a case, they should not long remain so, as they are then easily broken and exposed to dust and other evils. The casing may be accomplished in the following manner. Supposing the stone to be 9 in. long, 2 in. broad, and 1 in. thick, get 2 pieces of clean, straight, hard wood, 1 in. longer and wider than the stone, and 7/8 in. thick. Plane one side of each piece flat, so that they will lie closely together. On one of the pieces, place the stone, keeping uppermost the side of it which you mean to use. Draw a line all round the wood close to the stone, when you will have a margin outside the line of 1/2 in. With the brace and centre bit (5/8 in. or 3/4 in.) bore all over the portion within the line 1/2 in. deep, then with a sharp chisel 7/8 in. or 1 in.) cut down to the draw-point line all round, clearing out all within to 1/2 in. deep, and making the bottom of this hollow box level throughout.

If it is pared square down at the edges, the stone will slip into it; take care to put it in the same way as when you previously drew it. When the stone is bottomed, 1/2 in. will project above the wood, and this part is to receive the top or cover. The stone is placed upon the second piece of wood, which is to make the cover, and drawn in the same way; and this piece has to be bored and cleared out in the same way to fully 1/2 in. deep. It must have a smoother finish inside than the under piece; and must be pared a little without the draw-point line, so that the cover will slip on to the stone easily, but without shaking. The stone being within, the case is planed on the edges and ends, by catching it in the bench vice. The 4 corners may be rounded as well as the edge of the cover, and a 1/8 in. bead may be run round the cover where it joins the under part. (Cabe.) The oilstone will always wear most in the middle, becoming hollow in both length and breadth. This may not matter much for sharpening jack-plane irons, as the roundness thereby communicated to the corners of the cutting edge is rather an advantage. But when the hollow is of such a degree that it is inconvenient, the suiface must be levelled.

This maybe effected by rubbing it on a flat sandstone or grindstone, or by an emery slab, prepared by scattering emery powder on slips of wood previously well glued to bold it, and leaving for 24 hours to dry. The very best oil for use on the stone is either sperm or neat's foot, but this is often replaced by olive (salad) oil or by petroleum. In applying the tool, its bevel edge is rubbed to and fro on the stone, great care being necessary to ensure that the tool is held at exactly the same angle throughout the whole length of its travel backwards and forwards. That is to say, the natural tendency of the tool to lie flatter as it advances farther away from the operators body must be compensated for by raising the hand slightly as it goes forward and lowering it as it returns. 'Square the elbows, let hand and arms have freedom, grasp the tool above with the right hand so as to bring the fingers underneath it, and let the fingers of the left lie together, and straight upon the upper side, their ends tolerably near the edge of the tool, the thumb being underneath. The tool will be thus held firmly, and also under control. Holtz-appfel gives a way the reverse of this.

He says the first finger only of the right hand should be held above, and the thumb and rest of the fingers below, the left hand grasping the right, with the finger above the tool and the thumb below. It is probably in a great measure a question of habit. Apply the ground side of the iron to the stone, and rub backwards and forwards nearly the whole length of the stone. Hold the iron slightly more upright than at the grindstone, so that the extreme cutting edge only may come in contact with the oilstone. After 5 or 6 rubs on the bevel, turn the iron over and give it 1 or 2 light rub3 when lying quite flat on the stone. This double operation is repeated till a keenly sharp edge is obtained. If the irons are newly ground, very little setting is needed, but as they are dulled or blunted when working, a fresh edge has to be brought up on the oilstone; this sharpening may go on for 20 or 30 times before the irons require re-grinding. A blunt iron, looked at on the bevel side, presents a whitish rounded or worn appearance, and the sharpening has to be continued until this white worn edge disappears, which is also ascertained by touching the edge lightly with the thumb.

When an iron is sharpened or set, a very fine " wire edge " remains along the edge; this is removed by a dexterous slapping backwards and forwards on the palm of the hand, and is the same in effect as finishing the setting of a razor by stropping on a piece of leather. Gouges and bead-planes are generally set with a stone slip, several being necessary for the various bead and other moulding planes.

The slips are usually about 6 in. long, 2 in. broad, and 1/8 in. to 1/2 in. thick, with the edges rounded to fit the irons to be set. The cutting part of a bead-plane iron is a little smaller than the corresponding curve in the stock of the plane, the difference being the thickness of the shaving taken off. When the iron has been set a number of times with the slip, the curve has a tendency to get wider, and consequently is soon as wide as the curve in the stock. The iron will not then take off a shaving of equal thickness throughout the whole curve, but thickest in the middle, so the iron must be reground and set anew by the plane-maker, who has very thin round-edged grindstones for the purpose. The same thing occurs with most other moulding planes. In setting with the slip, the hollow part is continually getting wider, and the round part which is set on the ordinary oilstone is getting smaller. From these causes, the moulding gets out of proportion, and the iron does not fit the stock with a cutting edge even throughout its whole breadth, and will not turn a good shaving as before.

The tool-maker must re-grind the iron when in this condition. (Cabe.)