Читать книгу The Young Mechanic - James Lukin - Страница 6

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The method of constructing a simple box has been given in the first chapter, because so many other articles are made upon exactly similar principles. The rules laid down comprise two or three essential points, the neglect of which render the ordinary carpentry of boys so essentially bad. Foremost of these is the use of the square. There is no tool of more general use in the hands of workmen in wood and metal, and yet, generally speaking, either none at all, or a very faulty one is added to the collection of tools ordinarily supplied to boys. In the next place, I have insisted upon accuracy in measurement. The carpenter’s rule is not at all difficult for a young boy to understand; but even if he is not in possession of such at his first attempts, he should always be induced to work by measure of some kind. This causes him of necessity to exercise his mind as well as his hands, and teaches him to consider well at starting as to what he must allow for thickness of wood, the difference between inside and outside measurement, and so forth; all this will greatly conduce to his success, and consequently satisfaction in his work, and will lessen the chances of his beginning a number of articles and casting them aside unfinished—a propensity too common in all boys.

I shall now resume my directions in the first person, which I think is the more easy method both for master and pupil. The next specimen I propose, because it requires even more care than a box, but is at the same time perfectly within a boy’s powers, is a birdcage. Of these there are such a number of varieties that it is difficult to settle upon the best kind to begin upon. I think, however, a wire cage will on the whole be the easiest to construct, only you must take great care in boring holes in the thin strips of wood, and, indeed, if you can get a birdcage-maker’s awl besides the one you have, it will save both time and trouble. It is not made round with a flat end, but is three-cornered with a sharp point, so that it has three edges, and when it is carefully used and twirled round and round by the fingers in making holes, it will hardly ever split even very thin strips and pieces of wood. However, if you cannot get one never mind, you must use the common bradawl according to directions here given.

I shall suppose you now in possession of a carpenter’s rule, and that you have carefully learned all I told you of the inches and eighths, so that you may be able to measure and mark your work very truly. The front of the cage is represented in Fig. 9, before the projecting roof-boards have been put on.

Fig. 9.

Here you see two upright strips at the corners, which shall be 8 inches long. These are 12 inches apart, outside measure. They are ⅜ (three-eighths) of an inch square, and you must get them ready planed from the carpenter. There will be four of them required, as they are at the four corners of the cage; so that, as they are each 8 inches long, you can get a strip 36 inches in length by three-eighths wide, and this being 4 inches more than you need, will allow for waste. At the lower part of the drawing, you see the edge of the bottom board, which projects a little all round. As the outside of the front pillars are 12 inches apart, this board may be 13 inches long, which will allow a border of ½ an inch (half an inch), and it may be 8 inches wide. It need not be thicker than a quarter of an inch. A little above this board (say half an inch) is another board from one pillar to another, which is to be 1¼ inches wide and three-eighths of an inch thick. As the pillars are also three-eighths thick, and their outside edges 12 inches apart, you must take 6/8 (six-eighths) of an inch from 12 inches to find the length of this board.

If you look at the divisions upon your rule, you will see that six-eighths of an inch amounts to exactly ¾ (three quarters), so that your board must be 11 inches and one quarter long. This will also be the length of the board at the top where it falls between the pillars, and this too must be three-eighths thick.

I shall now show you how to mark and cut this top piece into the shape here sketched. Cut the board first of all into an oblong, and mind that you mark it by your square, so that the ends shall be square to the sides. Let it be 2½ inches wide. Here it is (Fig. 10). Measure a length of 6 inches from either end to the middle at A, and make a mark at that place. Draw a line, C B, one inch from the opposite side, the whole length of the board, and mind you draw it correctly. You should measure an inch at B, and at C, and then draw a line from one point to the other along the edge of your rule. You must now draw two lines from the spot you marked at A to the ends of this line (where you see the dotted lines). In order to cut this piece, you must begin at A, not at B or C, or else if the saw should stick you will be sure to split off a strip right across the piece; but if it should stick when you are cutting from A, you will only split off a bit of one of the three-cornered outside pieces, which would not signify at all.

Fig. 10.

When you are sawing, be sure, as I told you before, not to cut into the line you have marked, but saw just outside it, so that the lines will be left upon the two sloping sides of the board. You may cut as close to it as you can, but you must not destroy it, and then you can with your knife neatly shave off the rough edges which the saw has made, until you have pared the wood quite neatly all along the line. If you cut this line out, you will no longer have any guide to work by. Cutting out guide lines is a very common fault, not confined to small boys or big ones. You will find it easy to pare this sloping side if you begin to work from A downwards to B and C, but you cannot cut it in the other direction. A carpenter would, of course, run his plane down the slope, and so will you by and by; but planing is difficult, and it is better you should wait for a time before you buy a plane; for, remember, those foolish little things in boys’ tool-boxes are no use at all.

You had better now prepare the holes into which the wires are to be put as you see in the drawing. You can use either iron wire or brass, but the first is cheapest. These will have to be a quarter of an inch apart. Both the top and bottom strips, you will remember, are 11¼ (eleven and a quarter) inches long. Now, 11 inches will be 44 quarters, and one more will be 45; but as the first hole must be a quarter of an inch from the ends, you will find that 44 holes will be required. Look at your rule and count this. You must mark all these by little dots with a pencil on one piece, and then laying the other upon it, mark the rest exactly even with the first. Do this with great care, or the wires will not stand upright when the cage is finished. The space between the top and bottom pieces will be 5¼ inches, so that if you allow the wires to enter a quarter of an inch at the top and bottom, you will want 44 wires 5¾ inches in length—you may say, 6 inches. You can have them all cut and straightened for you, but if you have a pair of pliers with cutting edges, you can do it yourself, and it is almost necessary you should get a pair, or borrow them, if you intend to construct wire birdcages. You will want a few less in each side of this cage, as it will not be there so wide as it is in front. We shall presently see how many it will require.

You may put together the front of the cage at once and set it aside, or proceed to cut out the rest of it. Generally speaking, it is the best plan to cut out and prepare all the main parts of your work before proceeding to fix them in their respective places; but the front of such a cage as I am describing, being complete in itself, you may do as you like about it. We will begin with the wires. Insert the ends one after the other in a row in one of the pieces, laying it upon the bench, or fixing it on its edge in a vice, but taking care not to bend them. When one piece is thus stuck full of wires, lay it flat on its side, and put the other piece in its place, and one by one insert into it the other ends of the wires. A pair of pliers will help you greatly in doing this. I daresay the two pieces of wood will not be very parallel, but will be closer at one end than at the other. This does not matter, because you will set it right in nailing on the upright strips or corner pillars. This, therefore, is the next thing you must do; and you must have two brads top and bottom, each an inch long, but as fine as you can get. Nail to the top board first, and then place the other in position half an inch from the bottom of the pillars. If you have no carpenter’s vice, you had better work with the front of the cage laid down flat and near the right hand edge of the bench or table, so that the pillar almost overlaps it. In this position, you can bore the two holes and nail it together; but be guarded as to splitting the pillars.

You ought now to have the front well and firmly put together and standing square and true as in the sketch; only the bottom board, of which you see the front edge, is not to be attended to at present.

Fig. 11.

There is another way of going to work, namely, to put the whole framework of the cage together and add the wires afterwards. In this case (the holes having all been made beforehand as directed here) the wires are in turn inserted at the top, and then being slightly bent are put in place in the bottom piece—each wire being completely fixed before the next is added. Either way may be tried, but in that given above the wires are not bent at all, and therefore have not to be straightened. Adding them, however, afterwards is the common practice among the cage-makers. Indeed, it generally happens in large establishments that one set of workmen make the woodwork, and another set add the wires—such division of labour proving more advantageous.

Fig. 12.

Attention is now to be given to the sides, of which Fig. 11 is a drawing. Here you need not make any corner pillars. You have only to cut out the top and bottom strips—the lower one, 1¾ inch wide, to match that in front: the top, 1 inch wide, to match the straight part of the ends of the upper front piece or gable, as you see in Fig. 12. You will also see by this drawing that you must nail the side pieces inside the corner pillars, and not upon them, so that the nails go in from the front of the cage into the ends of the two side pieces which carry the wires. I have shown by dots (Fig. 12) where the nail holes are, and they must be carefully made, avoiding the places where the other two nails come, which you hammered in when you fitted together the front. The side strips, A B (Fig. 11), may be 8 inches long. Both sides of the cage are to be made exactly alike. I have told you to make the lower side-rails 1¾ inch wide, because they must come to the bottom of the pillars, for no half-inch space is required at the sides between these rails and the bottom of the cage. It is so left in the front, because a tray, or cleaning-board, has to be slid in there. You had certainly better put together the side pieces by means of the wires, as in Fig. 11, before you nail them in their places.

You now require a piece of board for the back, and quarter-inch stuff will do very well. Bought cages are made of much thinner wood, generally mahogany, but at first it will be easier for you to use thicker boards. If you round off the edges, they will not appear so thick. Very thin deal will warp or bend after it is made up; and, indeed, it is quite possible the back of this cage will do so. Get the wood, however, as dry as you can, and the top boards, when nailed on, will probably prevent it.

To cut out this back board, you may lay down upon the piece from which it is to be cut the whole front of the cage, and draw a pencil round it, only, when you come to the bottom of the side pillars, you must draw a line straight across from one to the other. Then cut from the point at the top, as you did before. Let the grain of the wood run up and down, not across, the back. Nail the back thus cut to the side strips, as you nailed on the front, and you will then only have the roof to put on, and the bottom.

This roof may consist simply of a thin board, cut square and true, nailed on to the two gables, and it will look much prettier if it is made to project beyond the front. If you measure down the slope of the front or back top-piece, you will find it 6 inches long, and a little more. Your board should therefore be 7 or 8 inches wide, because, although the roof pieces meet at the top, they should come down a little beyond the sides of the cage. As the sides are 8 inches wide, cut the top 11 inches long, which will allow it to project in front 3 inches.

If you look at the cage at the end of these directions, you will understand this. You must slope, or bevel off, the top edges of these roof boards, to make them fit neatly together along the ridge; and as you will paint the cage, you can glue on a narrow strip of paper, to make it quite water-tight. The door of these cages is generally in the back. You merely mark and cut out a square hole about 3 inches square. You then fit a piece in, and hinge it either with wire, or (which is easier) by sticking on a strip of calico down the edge of it, and fasten with a wire hook. As the back is but a quarter of an inch thick, you will be able to cut out the hole (before nailing on the back), with a sharp pocket-knife; and again I say, don’t cut out the guide-lines—cut inside them, and then neatly pare exactly up to them. Make the bottom 13 inches long, and 10 wide, which will allow it to project in front, and also half an inch on each side.