and the rougher the appearance, the softer the plank. That which is sawn comparatively smooth will be found hard and troublesome to work. If the plank has an uneven appearance-that is to say, if it is rough in some parts and smooth in others—the grain is crooked. Such timber is known to the trade as catfaced. In planing it, the grain tears up, and a nice smooth surface cannot be obtained. Before purchasing timber, it is well to note, what convenience the yard possesses for storing. Lumber on the pile, though it be out in all weathers, does not deteriorate, but becomes seasoned; nevertheless its value is much increased if it has an extemporized roof to protect it from the sun and rain; but as it is not convenient to visit the pile for every customer, quantities are usually taken down to await sale, and for such, a shelter must be provided, otherwise it will be impossible to insure that the lumber is dry, sound, and fit for pattern making; it being obvious that the foregoing remarks on the storage of lumber apply to all woods.

The superiority of pine for pattern making is not, however, maintained when we come to fine delicate patterns or patterns requiring great durability. When patterns for fine work, from which a great many castings are to be made, are required, a pattern wherefrom to cast an iron pattern is improvised, because, if pine were employed, it would not only become rapidly worn out, but would soon warp and become useless. It is true that a pine pattern will straighten more easily than one made of a hard wood; but its sphere of usefulness in fine patterns is, for the above reasons, somewhat limited. Iron patterns are very desirable on account of their durability, and because they leave the sand easily and cleanly, and because they not only do not warp, but are also less liable than wooden ones to give way to the sand, while the latter is being rammed around them by the molder-a defect that is often experienced with light

patterns, especially if they are made of pine. Iron patterns, however, are expensive things to make, and therefore it is that mahogany is extensively employed for fine or durable pattern work. Other woods are sometimes employed, because they stand the rough usage of the molding shop better and retain the sharp corners, which, if pine be used, in time become rounded, impairing the appearance of the casting. Mahogany is not liable to warp, nor subject to decay; and is for these reasons the most desirable of all woods employed in pattern making, providing that first cost is not a primary consideration. There are various kinds of this beautiful wood, that known as South American mahogany being chiefly used for patterns.

Next to mahogany we may rank cherry, which is a very durable wood, but more liable to twist or warp than mahogany, and it is a little harsh to the tool edge. If, however,

it is stored in the workshop for a length of time before being used, reliable patterns may be made from it. In addition to these woods, walnut, beech, and teak are sometimes employed in pattern making.

The one property in all timber to be specially guarded against is its tendency to warp, bend, expand, and contract, according to the amount of humidity in the atmosphere. Under ordinary conditions, we shall be right in supposing a moisture to be constantly given off from all the exposed surfaces of timber; therefore planks stored in the shop should be placed in a rack so contrived that they do not touch one another, so that the air may circulate between the planks, and dry all surfaces as nearly alike as possible. If a plank newly placed be lying on the bench on its flat side, the moisture will be given off freely from the upper surface, but will, on the under surface, be confined between the bench and the plank: the result being that a plank, planed straight and left lying as described, will be found, even in an hour, to be curved, from the con

traction of the upper surface due to its extra exposure; and therefore it is that lumber newly planed should be stored on end or placed on edge. Lumber expands and contracts with considerable force across the grain; hence if a piece even of a dry plank, be rigidly held and confined at the edges, it will shrink and rend in twain, often with a loud report. There is no appreciable alteration lengthwise in timber from the above causes; and if two pieces be glued together so that the grain of one crosses that of the other, they can never safely be relied upon to hold. Hence they had better be screwed, so that there will be a little liberty for the operation or play of the above forces, while the screws retain their hold. The shrinkage, expansion, and warping of timber may perhaps be better understood by considering as follows: The pores of wood run lengthwise, or with its grain, and hence the moisture contained in these passes off more readily endwise or from any surface on which the pores terminate. again the wood shrinks precisely in proportion in which the moisture leaves it; and if we have full knowledge of the direction of the grain, and of the position in which a piece of timber stands or lies, we can (all other things being equal, that is to say, supposing there to be no artificial heat or other disturbing cause operating on one more than on another side of it) predicate in what direction it will warp. Thus, let A, Fig. 1, be a piece of timber having the direction

B

Fig. 1.

B

Then

C

of its grain as denoted by the lines; then its surface, B B, which has the grain and pores terminating upon it, would allow free exit of the moisture, and that face would dry first

he corners, A B, are

The beveled face
Aot face. The

(especially if it lay uppermost) and we so that after a time the shape of the pi as shown in Fig. 2. Now if it had been placed to lay with the face, C, uppermost, the warping would have been much less, because the extra porosity of the face, BB, would have been counteracted by the lack of circulation of air. If, on the oth

B

Fig.2.

B

er hand, it was placed endwise, the warping, though it would have taken place, would have been appreciably less. It must not be supposed that thoroughly seasoning the timber will remove the tendency to warp, for timber, however long and carefully it has been dried or seasoned, undergoes considerable transformation of shape so soon as much of its outer surface is removed, making it appear that the seasoning or drying process takes place mainly at and near the outer surfaces, and is renewed every time an entirely new surface is presented to the action of the atmosphere. Thus, if we take a thoroughly seasoned piece of wood 3 inches square and 1 foot long, and cut it into strips 1 inch square and 1 foot long, the pieces will warp in a day or so; and if, after a few days, we take those inch strips and cut them into strips 4 inch square and 1 foot long, these latter will again warp; and no matter what pains might be taken with these last strips to season them and let them assume their new shape, were we to cut them into thin veneers the warping process would again set in. It is well, therefore, in particular work, to cut out roughly the various parts of the pattern, so that, while some parts are being operated upon, the others may be assuming their new shape, and thus become not so liable to warp after being worked up in the pattern.

One of our first requisites in the way of tools and appliances will be a carpenter's bench, which may be made as follows: Three pieces of stuff, 2x5 inches and 3 feet long, will serve for supports for the top. Two 12 inch boards, 12 feet long and 1 inch thick, will do for the sides. Nail these side boards firmly to the 2x5 inch cross pieces, and put on a top of suitable material, and the bench is ready for the legs. Now take four pieces of stuff, 2x5 inches, and of the requisite hight for the legs, and frame a piece 1x3 inches across each pair of legs, about 6 inches from the bottom, placing the legs at the distance apart necessary for the width of the bench. Then cut a fork or slit in the top end of each leg, so as to straddle the cross piece at the ends, and put a bolt 32x3% inches through each leg and through the side boards, and the bench will be complete; and it will possess the advantage that it can be taken down in a few minutes by removing the bolts from the legs.

The jack plane is employed for roughing off the surface timber; the stock is made of beech and the blade of cast steel. The blade acts most effectively when it is ground well away toward the corners, thus producing a curved edge, as shown in Fig. 3. When the blade is placed in the stock,

and in position to cut off the largest amount of stuff, its cutting edge should protrude through the face of the stock