chart. From the eye there branches a sort of geneo-
logical tree. The fork to the left runs down into two
colours, black and white, symbolizing the action of the
rods in the eye. The rods being that part of the
eye which recognizes the black and white in one's
surroundings.
Then the right-hand fork is sub-divided. One sub
division gives yellow and blue. The other gives red and
seagreen. This right-hand fork symbolizes the action of
the cones in the eye and the cones themselves fall into
two categories. The one, the older of the two, picks up
the yellow and blue; the other, the younger, i.e., the
latest in the process of evolution, picks up the red and
seagreen.
Because the red-seagreen group is the latest evolved, it
is naturally the weakest; the first to fall to disease or
some other physical defectand so colour blindness is
found more prevalent in the red-seagreen group.
Here, then, is the basic principle of colour recognition
based upon vision.
Now you will see that I have drawn a double-cone, the
apex of which rests in the eye and the base of which rests
upon the symbol of The Coal Industry* in the bottom
left-hand corner of my design. This double cone
represents The Ostwald Colour Solid.
The double cone of The Ostwald Theory is the one
which develops as you revolve an equilateral triangle
upon one of its sides, using that side as the axis. There
is a specific reason why Ostwald insists upon this
particular type of cone. His Colour Equation gives
c w b 1 where c colour, w white, and b
black; the whole, when translated into terms of per
centages, resulting in unity.
So with an equilateral triangle of this nature it is a
geometric truism "that the sum of the three lines drawn
from any point inside this triangle parallel to the sides
and taken to represent the respective amounts of c, w
and b in the colour at that point, must always be equal
to unity, i.e., to the length of a side" (J. Scott Taylor,
A Short Account of The Ostwald Colour System
This, then, is the beginning of the plan of the Colour
World. If you look at the Solid when it has been "made
up" and the created solid is a thing of startling beauty,
with its subtle gradations and its simplicityyou see
the whole idea laid before you as plainly as one sees a
cathedral arise from the plan and elevation of the archi
tect's drawings. In fact, the Colour Solid is the archi
tect's elevation drawing of the city of colour and
Ostwald is that architect.
At the apex of the solid is pure white which bears the
Indicating the link between the original Ostwald colours
and The Coal Tar Dye Industry.
220
index symbol (a). At the base of the solid is a black
which bears the index symbol (p), and between points
(a) and (p) stretches the grey vertical axis showing
step by step the easy transition from white to black.
This axis becomes the spine or spindle around which
the solid turns. This vertical axis stands erect through
a circle of pure hues, like a double-sided phallic symbol
in the days of its vitality. So you have the image of a
grey axis, encircled at the midway point by a ring of
hues. This ring or circle of hues contains twenty-four
hues, all equidistant the one from the other so that the
eye travels easily and quickly from hue to hue.
Diagram 1
Now as this circle of hues is divided into 24 parts and
each part a colour, it follows logically that as the eye
travels from each one of these hues towards the apex
of the cone where stands the white pinnacle, the
quantity of pure colour decreases as the quantity of pure
white increases. This transition from the hue to the
white is gradual and every step is determined arith
metically in terms of the Colour Equation c w b= 1
Because the colours which now appear upon the upper
cone show a white content, these newly formed
colours are known as the tints.
Going back again to the circle of hues, allow the eye to
travel from this circle towards the base where the black
is situated. Again it stands to reason that as one moves
away from the hue and draws nearer and nearer to the
black the quantity of hue decreases as the quantity of
black increases. The eye travels with ease over these
new colours which show a black content and these new
colours are termed the shades.
Going again to the circle of hues, there is yet another
point of contact to be explored. This is the one which
lies upon the grey axis itself and situated midway
between (a) and (p). All colours working from the
circle towards the central point decrease in hue content
as they increase in a grey contentand these in terms
of practical exposition we call the shaded tints.
To come now to the practical side of this workthe
side that interests the majority of folk in the colour
world there is this to be said at once. It is possible to
have ideal colours which are not possibleor which
are practically impossible to obtain in paint.
This may be instanced by reference to the black and
the white. The ideal black, the ideal white and the ideal
full colour would be those entirely free, the black
entirely free from white, the white entirely free from
black, and the full colour entirely free from black and
white. This is not possible in terms of paint except
perhaps in the instance of Gouache White of special
manufacture. So the following table of contents shows
