Convex Surfaces
: DRAWING AND ITS UTILITYIn Fig. 127 the shading is very light along the upper margin, and heavy at the lower margin. The first shaded figure, therefore, represents a concaved surface, and the second figure a convex surface. But why? Simply for the reason that in drawings, as well as in nature, light is projected downwardly, hence when a beam of light moves past the margin of an object, the contrast at the upper part, where the light is most intense, is strongest.
The shading of the S-shaped surface (Fig. 128) is a compound of Figs. 126 and 127.
Fig. 132. 
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Braces
It would also be well, in putting up the studding, to use plenty of braces, although for a one-story building this is not so essential as in two-story structures, because the weather boarding serves as a system of bracing. <div> <img src="/images/fi... Bridges
Bridge building is not, strictly, a part of the carpenter's education at the present day, because most structures of this kind are now built of steel; but there are certain principles involved in bridge construction which the carpenter should master... Building Plans
We must first have a plan; and the real carpenter must have the ability to plan as well as to do the work. We want a five-room house, comprising a parlor, dining room, two bedrooms, a kitchen and a bathroom. Just a modest little home, to which we ca... Bungalow Types
If you will take up any book on bungalow work and note the outlines of the views you will see that the roof forms the main element or theme. In fact, in most buildings of this kind everything is submerged but the roof and roof details. They are made... Cabinets
In the making of cabinets, sideboards, dressers and like articles, the ingenious boy will find a wonderful field for designing ability, because in these articles fancy alone dictates the sizes and the dimensions of the parts. Not so with chairs and ... Care Of Tools
Dull tools indicate the character of the workman. In an experience of over forty years, I have never known a good workman to keep poorly sharpened tools. While it is true that the capacity to sharpen tools can be acquired only by practice, correct h... Ceiling Joists
We are now ready for the ceiling joists, which are, usually, 2" × 6", unless there is an upper floor. These are laid 16 inches apart from center to center, preferably parallel with the floor joist. It should be borne in mind that the... Centering Blocks
Next provide a 4" × 4" piece (G), 40 inches long, through which bore a ¾-inch hole (8), 2 inches from the upper end, and four bolt holes at right angles to the shaft hole (8). Then, with a saw split down this bearing, as show... Chamfered Tenons
The object of these chamfered or beveled tenons is to permit the ends to approach each other closely within the mortise, as shown in the assembled parts (Fig. 36). ... Chisels
Two kinds are found in every kit—one called the firmer (Fig. 7) and the mortising chisel. The firmer has a flat body or blade, and a full set ranges in width from three-eighths of an inch to two inches. The sizes most desirable and useful ar... Chisels
I have already pointed out, in general, how to hold tools for grinding purposes, this description applying particularly to chisels, but several additional things may be added. Always be careful to grind the chisel so its cutting edge is square with ... Circles And Curves
Circles, and, in fact, all forms of curved work, are the most difficult for beginners. The simplest figure is the circle, which, if it represents a raised surface, is provided with a heavy line on the lower right-hand side, as in Fig. 146; but the p... Colonial Type
For real beauty, on a larger scale, there is nothing to-day which equals the old Colonial type with the Corinthian columns and entablature. The Lee mansion, now the National Cemetery, at Washington, is a fine example. Such houses are usually square ... Common Trusses
One form is shown in Fig. 235, with a vertical king post. In Fig. 236 there are two vertical supporting members, called queen posts, used in longer structures. Both of these forms are equally well adapted for small bridges or for roof supports. ... Concave Surfaces
In Fig. 126 the shading lines commence at the upper margin, and are heaviest there, the lines gradually growing thinner and farther apart. ... Concrete Examples Of Work
A concrete example of doing any work is more valuable than an abstract statement. For this purpose I shall direct the building of a common table with a drawer in it and show how the work is done in detail. For convenience let us adopt the Mission st... Conventional Styles
Now, if you wish to depart from the conventional style of making a table you may make variations in the design. For instance, the Chippendale style means slender legs and thin top. It involves some fanciful designs in the curved outlines of the top,... Convex Surfaces
In Fig. 127 the shading is very light along the upper margin, and heavy at the lower margin. The first shaded figure, therefore, represents a concaved surface, and the second figure a convex surface. But why? Simply for the reason that in drawings... Correct Way To Hold Tool For Grinding
There is a correct way to hold each tool; see illustration (Fig. 17). The left hand should grasp the tool firmly, near the sharp edge, as shown, and the right hand should loosely hold the tool behind the left hand. There is a reason for this which... Cross-cuts
The difference between a cross-cut and a rip saw is, that in the latter the teeth have less pitch and are usually larger than in the cross-cut saw. The illustrations (Figs. 13 and 14) will distinctly show the difference in the teeth. When a cross-cu... Cutting Out The Spaces
In cutting out the intervening spaces, which should be done with a sharp chisel, care should be observed not to cut over the shoulder lines. To prevent mistakes you should put some distinctive mark on each part to be cut away. In this instance E, H ... Definition Of Degree
A degree is not a measure, as we would designate a foot or a pound to determine distance or quantity. It is used to denote a division, space, interval or position. To illustrate, look at the circle, Fig. 51. The four cardinal points are formed by th... Definitions
The following figures show the various geometrical forms and their definitions: <div> <img src="/images/fig151_165.jpg" alt="Fig. 151.-Fig. 165." title="" height="640" width="104" /> </div> 151. <em>Abscissa.</em>—The point in a curve, A, which ... Degrees Without A Compass
But in the absence of a compass and when you do not wish to step off a circle, you will in such case lay down the square, and mark off at the outer margin of the limbs two equal dimensions. Suppose we take 2 inches on each limb of the square. The a... Depressed Surfaces
If, by chance, you should make the upper and the left-hand lines heavy, as in Fig. 134, it would, undoubtedly, appear depressed, and would need no further explanation. Full Shading,—But, in order to furnish an additional example of the effect ... Depth Of Mortises
When a certain article is to be made, the first consideration is, how the joint or joints shall be made. The general rule for using the tenon and mortise is where two parts are joined wherein the grains of the two members run at right angles to ea... Determining Angles
Now, in order to lay out work the boy should know quickly and accurately how to determine various angles used or required in his work. The quickest way in which to learn this is to become familiar with the degree in its various relations. <div> <im... Differences In The Working Of Woods
Different woods are not worked with equal facility by all the tools. Oak is an easy wood to handle with a saw, but is, probably, aside from ash, the most difficult wood known to plane. Ash is hard for the saw or the plane. On the other hand, ther... Diversified Uses
For a great overhang you may use the cavetto, or the apophyges, and below that the astragal or the torus; and for the base the casement is the most serviceable molding, and it may be finished off with the ovolo or the cymatium. Pages of examples mig... Dovetail Joints
It is in the laying out of the more complicated dovetail joints that the highest skill is required, because exactness is of more importance in this work than in any other article in joinery. In order to do this work accurately follow out the example... Ellipses And Ovals
It is not necessary to measure the centering points (F) at certain specified distances from the intersection of the horizontal and vertical lines. We may take any point along the major axis, as shown, for instance, in Fig. 149. Let B be this point, ... Errors To Be Avoided
Never draw back the plane with the bit resting on the board. This simply wears out the tool, and if there should be any grit on the board it will be sure to ruin the bit. This applies particularly to the jack plane, but is bad practice with the ot... Filing
The next step is the filing. Two things must be observed: the pitch and the angle. By pitch is meant the inclination of the teeth. Note the illustration (Fig. 13), which shows the teeth of a rip saw. You will see at A that the pitch of the tooth is ... Filing Angles
In its proper place will be shown how you may easily calculate and measure degrees in work of this kind. Fig. 12 shows an approximation to the right angle. B, B (Fig. 11) should be a pair of wooden pegs, driven into the wooden block on each side of ...