The Artist's Repository, Or, Encyclopedia of the Fine Arts (Band 2): Perspective, Architecture (London, 1808)

114

ON PERSPECTIVE. [LECT. ttl.

PLATE XLII.

No. I. In this example we have a wall (G), and*
at right angles with it, another wall, with a door-
way in it. H L is the horizontal Jine; the fun is
fuppofed in the plane of the picture j the inclination
of its rays, to be R H.

Firft, from the bottom of the projecting wall,
rule a horizontal line to the bottom of the wall G;
where erect a perpendicular, which, cut by a line
from a parallel to R H, gives u for the fhadow of a,
which unite to t. Or, rule from R, (u> which
equally gives the fhadow of the top taat u: c
and d are exactly fimilar.

The fhed D is fhewn more diftin&ly in the fol-
lowing Number; the fyftematic lines are the fame.

No. II. The wall B (to which the fide of the
fried to s is parallel) vaniflies in L.

The wall A vanifhes in H, the roof of the^fhed
in G; T reprefents the inclination of the rays of
light.

Firft, draw Azoy where erect zvs: then draw R
through (Inking the top of the fhed in u; there
remains now only that part of the fhadow which falls
on the roof. Rule G through u; interfe£t it by a line
from ay parallel to the rays of light, as at r, which
unite to s. Or this part of the fhadow may be found,
by ruling Q, h, cutting A h in h> then rule hsr.

PLATE