UO PERSPECTIVE DRAWING MADE EASY, 
horizontal surface : these same letters in fig. 
3 point out the same objects in elevation ; 
and fig. 2 is a perspective view of them. 
3. In order to draw the perspective view, 
make first the ground plan and elevation, 
as in figs. 1 and 3, then draw a line « i in 
fig. 1, to represent the transparent plane, 
which stands perpendicular to the surface 
on which the objects A B, &c. stand ; and 
after this, fix upon the point e, in the same 
fig, for the position of the eye. But before 
making a full view, it may be as well to 
illustrate the method, by finding the per- 
spective of the line d e, in fig. 1, which 
stands perpendicular to the transparent 
plane. The point f, which marks the posi- 
tion of d e, in the elevation, is on a level with 
the eye. From the ends of the line d c, 
draw the lines d c and e c to c, the point of 
sight; and the part /d! of the transparent 
plane or picture -sheet contained between 
the lines d c and e c, will be the perspective 
in the ground plan of the line d e, because 
the lines d c and e c represent the rays of 
light reflected to the eye from the ends of 
the line d e. From what is now said, it will be 
evident that/’/i shows the perspective in the 
ground plan of the part e of the line d e, 
and that k d is the perspective in the same 
plan of g d, the other part of d e. If a line 
is drawn through c, parallel to d e, till it 
meets the picture-sheet in i, r d will show, 
in fig. 1 , the perspective of the line d e, 
if it is indefinitely extended in the direction 
d e. For by inspecting the ground plan, 
it will be seen that the more distant from 
the picture sheet any point e is taken, the 
line drawn to the eye from that point 
becomes more nearly parallel to c i, and in 
consequence of this, 2 / becomes smaller the 
more distant the point is taken. Although 
we cannot name a distance from the picture- 
sheet for the position of the point c that will 
make i and/ exactly coincide, yet we can 
place e so distant, that the space betwixt i 
and y* will be smallar than any quantity that 
we can form a notion of, and for this reason 
V d must be considered the perspective in the 
ground plan of the line d c, when it is 
indefinitely extended from the point d in the 
picture-sheet, or from the point/in the eleva- 
tion on a level with c, the point of sight in 
the same view. 
4. We now know how to represent on an 
edge view of the transparent plane or picture- 
sheet, the perspective of any line or part of 
a line running pei*pendicular to the trans- 
parent plane on the same level with the eye ; 
but in order to make a picture, the perspec- 
tives of the lines in the objects to be repre- 
sented must be shown, not on an edge, but 
on an elevation of the picture-sheet. Let 
figs 2 be this elevation, and in this fig. drawn 
the line a h, which is just a continuation of 
ab hv fig. 3, the line representing the sur- 
face on which the objects stand ; then draw 
a line perpendicular to a h, in the perspective 
view, from the point c, in fig. 1, and a 
horizontal line c m from c, which marks the 
position of the eye in the elevation, and the 
point c, in fig.2, where these lines meet, is 
the position of the eye in the perspective 
view. The points c and i in the ground 
plan coincide in the perspective view, as 
the line d c stands perpendicular to the 
picture sheet in the side as well as in the 
up and down direction. And as this line 
<?<?has its commencement at the picture- 
sheet on a level with the eye, if lines are 
let fall from the points dh and /, in the 
ground plan, perpendicular to the line a b, 
in the perspective view, these perpendicu- 
lar lines will cut the horizontal line cm, 
in fig. 2., in the points and/, and these 
points will be the perspectives of the points 
marked d,g, and c, respectively, in the 
ground plan. If the points d and /, in 
fig. 2, are joined, the line df, will be the 
perspective of the line d e ; the part d e 
of this perspective line, is the perspective 
of d g, part of d e, and a line joining the 
points d and c, in fig. 2, is the perspective 
of the line deio. the ground plan, when 
it is indefinitely extended in the direction c? e. 
5. Let the line fig. 1, have its com- 
mencement in the elevation at d, one of 
the corners of the cube A; its perspective 
view is found as follows : — From the point 
d,m fig. 1, draw a line do, perpendicular 
to the line a b, in the perspective view ; 
and from d, fig. 3, draw a line d n, parallel to 
a b in fig. 2, and the point n, where the 
line dn cuts the line 0 , is the commence- 
ment of the perspective of the line d e ; 
join n c, and this line will be the perspec- 
tive of the line de, when it is indefinitely 
extended. A line joining the points 0 and 
eis the perspective of the line de, if it is 
indefinitely extended when it has its posi- 
tion in the elevation at the corner of the 
cube under d. The point 0 , where the 
perspective line 0 c commences, is found 
in the very same way as the point n was 
found. As nc is the perspective of de, 
when it is indefinitely extended from d, 
in fig. 3, one of the top corners of the 
cube A ; and as 0 c is the perspective 
of d e, when it is indefinitely extended 
from the corner under d of the cube A- 
in fig. 3, the triangle wco is the perspec- 
tive of a parallel surface, standing perpen- 
dicular to the surface on which the objects 
A, B, &c. stand, and running at right 
angles to the picture-sheet to an indefinite 
distance from it. The side of the cube A, 
that is, towards the centre of the picture. 
