First lessons in woodworking

The series of lessons in wood-working here presented is intended, principally, for use in schools in which hand-work is pursued as a part of general training. The order of sequence is designed to lead the pupil from one tool to another of larger capabilities, and from one operation to another requiring a higher degree of skill.
In writing the descriptions of operations the aim has been to make them so full as to enable an intelligent pupil to perform the operations tolerably well, even without the help of an instructor, and at the same time to direct the attention of the instructor to the principal points that he ought to insist on, and the principal errors that are found to occur.
The work being designed for young pupils, say between the ages of eleven and fourteen, it is not intended to go over much ground, nor to impart great skill, but only to open the way, reserving for another volume a more extended course. For the same reason, a thorough analysis of the mode of action of each tool is not attempted: this belongs rather to the teaching in a technical school, and should have its place in a more advanced work for higher classes. Nevertheless, it is intended, not merely to teach the pupil how to handle the tool, but also to form in him the habit of considering how the tool operates, and what modifications it requires to adapt it to different uses, affording thus training not only for the hand and the eye, but for the attention and judgment as well, an end to which hand-work, properly conducted, is at least as well adapted as many of the other studies that have heretofore monopolized the attention of our schools.
With the exercises in the use of tools have been interwoven observations on the properties of the materials used, and elementary principles of mechanical drawing, with the idea that the three studies, thus blended together, would lend help and stimulus to each other, and thus be pursued with more zest than if taught separately. The division into lessons is necessarily, to some extent, arbitrary. The lessons may be found too long or too short, according to the time which the school may be able to allow. An intelligent instructor will easily combine them or subdivide them as occasion may require.

In Lesson XIII you planed up the sides of your box and put them away; and when you took them out again you found that they had shrunk in width though not in length, and you measured the amount of the shrinkage. You found also that some of the pieces had checked, and some had warped. When large pieces of wood are used, shrinkage, warping, and checking give rise to serious trouble. Thus, in a door 30 inches wide shrinkage may amount to half an inch or more, and warping to an inch, and long and wide cracks are almost sure to appear. Moreover, the shrinking does not take place once for all, and then come to an end, but the wood having once shrunk may swell again, and shrink again, and so on repeatedly. Doors that are exposed to the dry air of houses which are heated in winter become very loose, but sometimes swell up in summer so much as to stick. The shrinkage will be less if the wood has been thoroughly seasoned, but the swelling in damp weather can hardly be prevented.

Doors are therefore never made in one piece, but are always constructed of parts, so arranged as to reduce as much as possible the bad effects of these changes. There are two principal methods of construction by which this is accomplished. The first is the battened door and the second the paneled door. The battened door is made of strips, Fig. 60, running lengthwise of the door and held together by cross-strips or battens, fastened on with screws or nails. As the wood shrinks only in width and not in length, the shrinking of the strips will only cause the edges to separate a little, and will produce scarcely any change in the width of the door. The warping, also, in this case, will be small in amount. While a piece the whole width of the door might warp, as at a, Fig. 61, a battened door would appear as at b. The separating of the strips, leaving cracks in the door, is prevented by using "matched" boards, or "tongue and groove" joints, as shown in the plan Fig. 60, or on a larger scale in Fig. 62. In this case the tongues slip partly out of the grooves when the wood shrinks, but do not leave the joints open. This construction is simple and effective, and is much used where fine workmanship and handsome appearance are not important, as in the doors of barns and outhouses. For dwelling-houses and in cabinet-work the paneled door is used. This is a frame-work mortised together at the corners, and grooved all round on the inner edge to receive a thin piece called the panels shown in Fig. 63. The shrinking of the panel only causes it to slip in the groove. As the cross-pieces at the top and bottom undergo no change in length, the only alteration in width that the door will suffer is the slight one due to the shrinking in the width of the two upright pieces. We will proceed to make such a door from the figured sketch, in which A shows the elevation, B the plan, and C a section on the line a b.

The first step is to get out the material. This consists of the top and bottom pieces, called the rails, the upright sides, called stiles, and the thin central piece or panel. Take the dimensions of these from the drawing, and mark them out on boards of the proper thickness, being careful to allow for the saw-kerf and for the material which will be wasted in planing up the pieces to the true shape and dimensions.

The frame-pieces being cut out, they are to be finished to exact dimensions and true surfaces as in previous lessons. The joints are then to be marked out with gauge, square, and pencil, making all gauge and square marks from the front surface and inner edge of the pieces, which must be marked to distinguish them. The laying out of the joint in this exercise is complicated by two circumstances. The first of these is that the tenon must be made of less width than the full width of the rail, in order that the mortise may not run out quite to the end of the stile. The second is, that a groove is to be cut in the inner edge of the four pieces, and this groove, unless a special arrangement is made to prevent it, will leave a hole between the end of the stile and the shoulder of the mortise, as shown in the sketch of one joint at a, Fig. 66. To prevent this, a projecting stud, or tooth, is left on the tenon-piece, as shown in plan and elevation at a and b, Fig. 67.