DOI Page / Citation link:
https://doi.org/10.11588/diglit.18733#0051
[ 41 ]
habit os judging, and comparing objects with each
other ; and partly because the effect of light and shadow
decides the matter. This figure may illustrate the
supposition of Hopes in the Desart of Arabia, and
seems to confirm the idea, page 15. See more in
Lecture IV.
No. VI. Is intended to she-w, that when the plane
wherein any object is situated is parallel to the picture,
the representation of the object will be parallel to the
original, and exactly follow it: as appears by a I c d
which corresponds to A B C D.
PLATE IV.
No. I. Is a section explanatory of the principles
reasoned on in page 27. It represents the eye of a
spectator at three different situations, I 1. I 2. I 3.
The lines drawn from the various points of the objects
to the eye, shew (by the spaces they occupy on the
upright line immediately before the eye) in -what pro-
portion the eye diseerns the parts of such objects. As
sor insiance, to I 1, the Hope AB appears not much
larger than the small space B C : C D is totally unseen
by it; as is great part of D E, and E, F : G, H, it sees
distinctly ; but H K is a mere line, and therefore its
extent is not perceivable. To I 2 many of the parts
hardly discernable by I r, are very distinct, and it has
a view of H K from end to end : but the top of the
house is not seen by it; except as a line. I 3 has yet
greater advantages, which appear on inslection. This
sigure shews what is pojfible in perspective ; not only
horizontal, or vertical planes, may be delineated ; but
25 F Hopes
habit os judging, and comparing objects with each
other ; and partly because the effect of light and shadow
decides the matter. This figure may illustrate the
supposition of Hopes in the Desart of Arabia, and
seems to confirm the idea, page 15. See more in
Lecture IV.
No. VI. Is intended to she-w, that when the plane
wherein any object is situated is parallel to the picture,
the representation of the object will be parallel to the
original, and exactly follow it: as appears by a I c d
which corresponds to A B C D.
PLATE IV.
No. I. Is a section explanatory of the principles
reasoned on in page 27. It represents the eye of a
spectator at three different situations, I 1. I 2. I 3.
The lines drawn from the various points of the objects
to the eye, shew (by the spaces they occupy on the
upright line immediately before the eye) in -what pro-
portion the eye diseerns the parts of such objects. As
sor insiance, to I 1, the Hope AB appears not much
larger than the small space B C : C D is totally unseen
by it; as is great part of D E, and E, F : G, H, it sees
distinctly ; but H K is a mere line, and therefore its
extent is not perceivable. To I 2 many of the parts
hardly discernable by I r, are very distinct, and it has
a view of H K from end to end : but the top of the
house is not seen by it; except as a line. I 3 has yet
greater advantages, which appear on inslection. This
sigure shews what is pojfible in perspective ; not only
horizontal, or vertical planes, may be delineated ; but
25 F Hopes