Dorigny, Nicolas [Hrsg.]; Raffaello <Sanzio> [Hrsg.]; Ralph, Benjamin [Mitarb.]; Duchange, Gaspard [Ill.]: The School Of Raphael, Or, The Student's Guide To Expression In Historical Painting: Ilustrated By Examples Engraved By Duchange, And Others, Under The Inspection Of Sir Nicholas Dorigny, From His Own Drawings, After The most celebrated Heads in the Cartoons at the King's Palace. To Which Are Now Added, The Outlines Of Each Head, And Also Several Plates Of The Most Celebrated Antique Statutes, Skeletons, And Anatomical Figures, Engraved by an Eminent Artist. With Instructions For Young Students In The Art Of Designing. And The Passions, As Characterised By Raphael In The Cartoons. Described And Explained By Benjamin Ralph (London, [ca. 1804])

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18 EXPLANATION OF THE GEOMETRICAL FIGURES

FIGURE H.

To divide a given Circle into four equal Parts.
Draw a line through the centre C, and proceed as in Fig. I.

FIGURE III.

From a given point C, in a right Line, to erect a Perpendicular.

Set one point of the compasses in C, and, opening them at pleasure, set off the
distances A B, and proceed as in Fig. I.

FIGURE IV.

Upon a Point, situate at or near the end of a Line, to .erect a Perpendicular.

From the point B, on the line A B, extend the compasses, at pleasure, to the
centre C, from which describe a circle, and from the intersection in the line A B at
D, draw a line through C, which will cut the circumference at E, from which draw
a line to the point B.

FIGURE V.

Shews the manner of drawing parallel lines, which needs no explanation, and
may be drawn to any distance required.

FIGURE VI.

To form a Square from a given Line.
Erect a perpendicular (by the rule given in Fig. IV.) upon which and the base
line, set oif with the compasses the line proposed, and keeping the same distance*
draw the circular lines C D B, and A D B, from whose intersections at D draw the
lines D C and D A

FIGURE VII.

From two given Lines to form a Parallelogram, or long Square.

Draw the line C D at pleasure, upon which set off the longest given line A, erect
a perpendicular at E, upon which set off the given line B, mark off the line A
from F, and the line B from A, and draw the lines A G and G F.

FIGURE VIII.

From a given Line to form, an equilateral Triangle.
Take the length of the given line A B with the compasses, and from the points
A and B draw circular lines, from whose intersection draw A D and C B.