Nicholson, Peter: The student's instructor in drawing and working the five orders of architecture (London, 1823)

30

PLATE XXVIII.
TO DESCRIBE THE IONIC VOLUTE.

Divide the height P Q into seven equal parts,
upon the third division describe a circle about C as
a centre, whose diameter will be equal to one of the
parts ; draw the square V W X U, and in that square
draw another, whose angles shall touch the sides of
the former square in the middle. In order to make
the construction of the centres appear plain, the
centre part is shewn above of a larger size, and the
same letters of reference put to each; divide Cl
and C2 each into three equal parts at 9> 5; 10,
and 6; divide C 10 into two equal parts at x, if the
volute is intended to be on the right hand, as in this
example; but if on the left, divide C 9 into two
equal parts, and proceed in each case as follows:
from x draw the perpendicular line, cutting the side
S F of the square at D ; from D make D E and D F
equal to G 1 or G 2 ; join E H and F H, draw 5,4...
9, 8 ... 10, 11, and 6, 7, parallel to the perpendicular
side of the square, cutting E H, and F H, at 4, 8 .
3.7.11; then 1...2...3...4...5...6...7...8...
9... 10 ... 11 ... and 12, are the centres. Begin at 1,
and with the radius 1 A, describe the quadrant AB,
of the volute; on 2, with the radius 2 B, describe
the quadrant B C; on 3, describe the quadrant C D ;
proceed in this manner with all the quadrants, till
you touch the eye at U, and it will complete one
side of the fillet.