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The example of the house shows, by the shadows on B and C, that B stands further back than A, and C farther than B.

The shadows in the example which follows, exhibit the difference between the forms of three objects whose outlines are exactly the same. The shade on them cannot be represented in these outlines.

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13. What may be said of color, as a means of distinguishing objects from each other?

Of this, it is only necessary to observe, that when we have represented the form of an object, its light and shade, and its shadow, if we wish still further to distinguish it from other objects, we have but to add its appropriate color. For example, in the drawing of a machine, if we wish to exhibit the difference between the wood, the iron, and the brass, the natural colors of these should be added in the drawing.

14. What effect have shade and shadow?

Shade and shadow have the effect of obscuring the outline, form, and color, of that part of every object on which they are found. Hence shading, in drawing, is the ob scuring, in imitation of nature, of those portions of the objects we are representing, and from which the light is intercepted. There is this difference, however, between nature and art-in the former we distinguish and deter

mine forms. by means of the light; in the latter, by the shade and shadow.

15. By what is the process of shading regulated?

The process of shading a drawing varies according to the instrument used. The pen is capable of making only lines and dots; hence, if we employ it only, we are confined to those two methods of shading. The brush and lead pencil possess, in addition to the resources of the pen, the capability of laying a smooth, graduated tint of shade, which by the brush may also be made of any color that may be desired.

16. What may be said of the use of the pencil?

The acquisition of a skilful and easy manner of handling the pencil, depends in a great measure upon the way of holding it. The thumb, with the first and second fingers, should grasp the pencil

about an inch from its point. The thumb should not be drawn back, as we are taught in holding a pen for writing; but should be placed opposite

to, or a little below the points of the fingers. This position will enable the hand

to move from left to right, and to draw curved lines with as much freedom in that direction, as from right to left..

Let the learner now practise the drawing of such lines as are shown in the figure, from left to right.

In drawing straight lines by the hand, the learner should

not begin by timidly drawing dotted lines, as is usually done; but the pencil should be passed rapidly two or three times from one extremity of the line to the other, without touching the paper, and then the line should be drawn at one stroke. Should it not be correct, repeat the trial until it is right; after which, and not before, efface whatever is wrong.

In the same manner, curved lines may be first sketched out by drawing broken lines, and after

not thus,

but thus.

wards rounding off the angles and effacing the straight lines. These distinctions may appear trifling, and too minute, but nothing is more certain than that a careful and intelligent observance of them, will ensure a rapid and easy manner of sketching.

GENERAL REMARKS.

It is not intended, nor would it be possible, to give here more than a few practical hints concerning the general principles of the art of drawing. The learner, after familiarizing himself with them, and with the short directions as to the mechanical part, should copy some good drawings, under the direction of an instructor. He should then take some simple object, such as a book, a cup, an inkstand, &c., and placing it before him, endeavor to describe its position and proportions by means of its outline. This is done by comparing the lines which make up its outline with each

other, regarding both their comparative length and the angles which they make with each other. If the direction and relative length of each line are right, the drawing must be correct.

An easy help in finding

the direction of a line nearly

vertical, is to hold at arm's
length, between the
eye and
object, (a pyramid, for ex-
ample,) a ruler which serves
as a plumb line. The edge
of the ruler being vertical,
when brought in range with
the point A, will show how
much the line AC varies
from a perpendicular.

Now by drawing, or imagining to be drawn, a vertical line upon the paper, and then drawing a line making with it an angle equal to BAC, we shall have the direction of AC, or its inclination to a plumb-line AB.

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auxiliary level line upon the paper, and then laying down the angle CAB, we shall have the direction of AB, or its inclination to a horizontal line. This method is applicable

to the lines of distant objects, as well as to those which

are near.

Having acquired by practice the power of sketching a single object in outline, the learner should place two or more objects before him, and endeavor, by means of drawing their outlines, to represent, in addition to their forms, their relative position with respect to each other. He should then proceed to shade them, and to draw the shadows which they cast upon each other, and upon the table or other surface on which they may be placed. The colors of the lights, shades, and shadows may then be added, and the . representation will be complete.

SECTION II.

TOPOGRAPHICAL DRAWING.

1. What is Topographical Drawing?

Topographical Drawing is the art of representing upon a plane surface, the character and features of any piece of ground. Such drawings are always plans, and are distinguished from geographical maps by a greater degree of minuteness in their details. A system of signs has been universally agreed upon, and adopted; most of which, however, have a sufficient resemblance to the objects for which they stand, to enable them to be easily recognised.

The signs in the annexed plates have been adopted by the Engineer Department, and are used in all the plans and maps made by the U. S. Engineers.

These we shall proceed to explain, giving at the same time such hints as to the manner of drawing them, as may appear to be necessary.

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