Fig. 235.
[ CXXIX]
An Arcade in Angular Perspective
First draw the perspective square ABCD at the angle required, by new method. Produce sides AD and BC to V. Draw diagonal BD and produce to point G, from whence we draw the other diagonals to cfh. Make spaces 1, 2, 3, &c., on base line equal to B 1 to obtain sides of squares. Raise vertical BM the height required. Produce DA to O on base line, and from O raise vertical OP equal to BM. This line enables us to dispense with the long vanishing point to the left; its working has been explained at Fig. 131. From P draw PRV to vanishing point V, which will intersect vertical AR at R. Join MR, and this line, if produced, would meet the horizon at the other vanishing point.
In like manner make O2 equal to B2·. From 2 draw line to V, and at 2, its intersection with AR, draw line 2 2, which will also meet the horizon at the other vanishing point. By means of the quarter-circle A we can obtain the points through which to draw the semicircular arches in the same way as in the previous figure.
Fig. 236.