Ellipses And Ovals
: DRAWING AND ITS UTILITYIt 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, taken at random. Then describe the half circle (C). We may, also, arbitrarily, take any point, as, for instance, D on the minor axis E, and by drawing the diagonal lines (F) we find marks on the circle (C), which are the meeting lines for the large curve (H), with the small curve (C). In this case we have formed an ovate or an oval form. Experience will soon make perfect in following out these directions.
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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 ... First Requirements For Designing
First, then, let us see what is necessary to do when you intend to set about making an article. Suppose we fix our minds upon a table as the article selected. Three things are necessary to know: First, the use to which it is to be put; second, the d... First Requisite
A beginner should never attempt a piece of work until he learns how the different tools should be sharpened, or at least learn the principle involved. Practice will make perfect. ... First Steps
Now lap together the inner surfaces of these boards (Y, Z), so the ends are toward you, as shown in Fig. 45. Then, after measuring the thickness of the boards to be joined (the thinnest, if they are of different thicknesses), set your compasses, o... Flat Effects
If the board is flat it may be shaded, as shown in Fig. 131, in which the lines are all of the same thickness, and are spaced farther and farther apart at regularly increasing intervals. <div> <table summary="Fig 133/134" border="0" cellpadding="0... Flattened Perspective
Fig. 144 shows the new perspective, in which the three vertical lines (A, A, A) are of equal length, and the six angularly disposed lines (B, C) are of equal length, but shorter than the lines A. The only change which has been made is to shorten the... Fly-wheel
It now remains only to provide a fly-wheel and treadle with the communicating belt. The fly-wheel may be of any convenient size, or it may be some discarded pulley or wheel. Suppose it is two feet in diameter; then, as your small pulley is 2 inches ... Focal Points
The focal point of a circle is its center, and is called the <em>focus</em>. But an ellipse has two focal points, called <em>foci</em>, represented by F, F in Fig. 148, and by B, B in Fig. 149. A <em>produced line</em> is one which extends out beyo... For Cross-cutting
For ordinary cross-cutting the angle of the saw should be at 45 degrees. For ripping, the best results are found at less than 45 degrees, but you should avoid flattening down the angle. An incorrect as well as a correct angle are shown in Figs. 21 a... Forcing A Saw
Forcing a saw through the wood means a crooked kerf. The more nearly the saw is held at right angles to a board, the greater is the force which must be applied to it by the hand to cause it to bite into the wood; and, on the other hand, if the saw... Forcing Saws In Wood
One of the reasons why the forcing of saws is such a bad practice will be observed in cutting white or yellow pine. For cross-cutting, the saw should have fine teeth, not heavily set, and evenly filed. To do a good job of cross-cutting, the saw must... Forming Lines And Shadows
It is not my intention to furnish a complete treatise on this subject, but to do two things, one of which will be to show, among other features, how simple lines form objects; how shading becomes an effective aid; how proportions are formed; and, ... Framework
As we now know the sizes, the first thing is to build the framework. The legs should be dressed square and smoothed down with the fore plane to make them perfectly straight. Now, lay out two mortises at the upper end of each leg. Follow the illust... Front And Side Lines
From the floor diagram, and the door and window spaces, as marked out, we may now proceed to lay out rough front and side outlines of the building. The ceilings are to be 9 feet, and if we put a rather low-pitched roof on the square structure (Fig. ...