An Improved Method and Means for Teaching Perspective Drawing.
Year: 1890

page_text: Date of Application, 14th Apr., 1890
Complete Specification Left, 3rd Jan., 1891-Accepted, 7th Feb., 1891
PROVISIONAL SPECIFICATION.
An Improved Method and Means for Teaching Perspective Drawing.
JAMES RIDDEL, Art Master, Heriot-Watt College, Edinburgh, residing at Jane-
ville, Colinton, Midlothian, do hereby declare the nature of this invention to be as
follows:-
A model to illustrate the principles of perspective, and at the same time to show
how those principles are applied when making a perspective drawing.
First. The picture plane is so arranged at A, Figure I, that it is in its normal
position in relation to the spectator (eye) and objects D, &c.—that is to say, at right
angles to the line of direction C, and between the spectator and the objects to be
drawn. Upon the picture plane in this position, looking from the eye, may be
traced the appearance of objects beyond-and from this the laws of perspective may
be illustrated, for instance, it can be shown to what points the outlines of objects,
as D, appear to converge, ris. to V & V2. It can be shown also that a line drawn
from the eye, as E, parallel to the outlines, as F, of objects beyond will also
determine the converging point V.
Second. The picture plane may be revolved into a horizontal position, as B.
Fig. I. on the horizon line (V1, CV, V2) as an axis. I will now be in the same
plane as the eye, and the lines, as C. E. drawn from the eye. This being the
position of the picture plane when making a perspective drawing, it is now possible
to show how all the principles or laws of perspective, illustrated when the picture
plane was in its first or normal position, can be applied when working out per-
spective drawings.
The picture plane may be of any convenient material, either altogether trans-
parent or transparent only in the centre G, and mounted in any suitable frame.
The lines drawn from the eye as C. E. &c. may be of thread, wire, or such like
material.
In a modified form, shown in Fig. II. the model may be altogether made of
cardboard or stiff paper, with threads for the lines from the eye. But instead of
the picture plane A. revolving on the horizon line as its axis, it will revolve on its
intersection with the ground plane. The upright D representing the spectator
also revolves about its intersection with the ground plane. The upright D. and
the picture plane A may revolve, from their normal position, either backwards or
forwards, and in either case will show the eye, the picture plane, &c. in what may
be called the working position.
Such a folding model as this, may be arranged to form a page of a book.
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JAS. RIDDEL.
COMPLETE SPECIFICATION.
An Improved Method and Means for Teaching Perspective Drawing.
JAMES RIDDEL, Art Master, Heriot-Watt College, Edinburgh, residing at Jane-
ville, Colinton, Midlothian, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
Being a model to illustrate the principles of perspective drawing, and to
demonstrate the application of those principles to perspective drawing. The
drawings hereinafter referred to, are those filed with the Provisional Specification.
First. The picture plane is so arranged (A Fig. I.) that it is in its normal
position in relation to the spectator (eye,) and objects (D) &c.—that is to say at

page_text: right angles to the line of direction (C), and between the spectator and the objects
to be drawn. Upon the picture plane in this position, looking from the eye, may
be traced the appearance of objects beyond, and from this all the laws of perspective
may be illustrated.
Second. The picture plane may be revolved into a horizontal position (as B
Fig. 1.) in this case on the horizon line (V' C V. V) as an axis-and it would then
be in the same plane as the eye, and the lines drawn from the eye, (as C. E.). This
being the position which the picture plane occupies in an ordinary perspective
drawing, it is now possible to show how all the principles or laws of perspective,
illustrated when the picture plane was in its first or normal position, can be applied
when working out a perspective diagram.
The picture plane may be of any convenient material, either altogether trans-
parent, or transparent only in the centre G, and mounted on any suitable frame,
and so mounted that it may be removed at pleasure, to allow a variety of diagrams
to be shown on the same frame.
The lines from the eye may be of thread, wire, or such like suitable material.
In a modified form the model may be so constructed as to form a page of a book,
as Fig. II. But the picture plane instead of revolving on the horizon line as an
axis, will revolve about its intersection with the ground plane C. The upright, D,
representing the spectator will also revolve about its intersection with the ground
plane. The upright D, and the picture plane A, may revolve either backwards or
forwards, and in either case will show the eye, the picture plane &c. in what may
be called the working position.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is-
The rotating picture plane, in a model illustrating perspective drawing-and so
rotating that it may be in-First-what is described above as its normal position,
and in-Second-what may be called the working position-being an improved
method and means for teaching perspective drawing.
Dated this First day of January Eighteen hundred and ninety-one.