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make a reduction, say of one fourth, fifth, or

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The composition finished, a network of lines parallel to the vertical and horizontal sides of the sheet is traced on the sketch, making the spaces between them into squares, measuring, for example, one centimetre on each side. This network of squares is generally termed sections, and each vertical or horizontal division is numbered 1, 2, 3, &c.

By thus tracing on the canvas a network of similar squares in the chosen proportion, with the same indication of the divisions by numbers, we obtain a practical means of enlarging the sketch as may be desired.

General Remark. In examining fig. II., we notice that, whatever the distance of the figures from the base-line, the horizontal line cuts all of them in proportional parts; in other words, if the figure E E' is cut by HH' at a point N in such a way that E' N is the two-fifths of the total length, all the other standing figures of the picture should have two-fifths above the horizon, and three-fifths below it.

This observation discovers a rule which can readily be used in pictures where there is any great assemblage of persons-in battle scenes for instance.

Application (fig. VI.)—To determine the size of a person at a point Z', which is comprised between H' II' and A B, the limit for figures placed on the horizontal plan of the picture.

I draw the vertical line Z' I. The measurement of AH in connection with H T shows us that the horizontal line cuts the figures of the picture at three-fifths of their proportional vertical height. Therefore Z I represents two-fifths of the figures sought. Taking the half of this length (Z' I), we carry it three times along the vertical line below HH', and thus find the feet of the figure resting on the ground.

The size of the head is determined by the known method.

If the horizontal line passed above the figures, the reasoning and solution of the questions would be the same (fig. VII.)

The rules found hitherto are only applicable to figures resting on the same horizontal plan as the painter; and it will at once be seen that a modification of these rules must be introduced, whenever there is a change of plan; that is to say, whenever certain figures are found to be more or less above or below the level of the ground, properly speaking, of the picture.

Of Figures placed on a Ground more or less Elevated.

In the composition of a picture, it frequently happens that certain figures occupy such or such a place at a window, on the steps of a ladder, of a tribune, etc. How are we to determine

their size?

This question, so complex at first sight, is easily resolved on the following principle :

Whatever may be the height of a figure above the ground of the picture, or its attitude, its size measured on the vertical line passing through the axis of its body is the same when taken at the foot of the vertical line as it is at any other point of it.

Thus a figure placed at a window is of the same size as one placed at a corresponding window above or below on the same vertical line.

It is the same of a statue on a column, in a niche, on a pedestal, or on any elevation of the ground.

This rule, which seems paradoxical at the outset, is strictly true, but on an express condition: which is, that the spectator shall place himself at such a distance that he will be able to embrace at a single glance the two extremities of the building, the column, etc. Without this, if he were too near, he would perceive the object situated at the foot of the vertical line, under a first visual angle,

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and then, without suspecting it, raising his eyes to the figure situated at the summit, he would not take into account that the direction of the eye had changed, and therefore would alone attribute the difference of dimension apparently existing between the two objects, to a greater or less elevation above the ground.

One may experience this from nature by observing the windows of a house. If the observation be well made, it will be easy to account for this fundamental principle.

Example (fig. VIII.): Find at point X the size of a figure elevated 0·50 metre above the ground.

1st. I find the size of the figure when on the ground by means of the scale of proportion; let it be X X'.

2nd. Starting from X on the vertical line X X', a length of 0.50 metre is measured to scale, let this be X R.

3rd. On the same vertical line, starting from the point R, I put down the length R R', which is equal to X X'.

If a part of the figure should have to be hidden, say a half, third, or fourth, by the ground of the picture, the rule given at page 11 will be applied.

PART THE SECOND.

CHAPTER I.

Distance.-The Station (or Point of View).-The Principal
Vanishing Point.

DISTANCE (fig. I.) is the space which separates the spectator from the picture, and is represented by the visual ray O V, which is brought down perpendicularly, in the imagination, from the point on the canvas opposite the eye of the spec

tator.

The STATION is the point 0; that is to say, the eye of the spectator.

The PRINCIPAL VANISHING POINT is the point of meeting of the visual ray, O V, with the horizontal line.

This point can be fixed at any part of the horizontal line, according as the point chosen gives a better aspect to the figures or to the lines of the background of the composition.*

It should not in any case be placed outside the picture, which would oblige the spectator to stand

* By "lines of the background" is meant the perspective lines of a room, a street, or a landscape, as distinct from the perspective lines of the figures or accessory objects of a composition.

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