A NEW OR IMPROVED APPARATUS TO BE EMPLOYED IN THE CLASSIFICATION OF COLORS
Year: 1883

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills of the firm of Harris
and Mills of 23 Southampton Buildings in the County of Middlesex Patent
Agent for an Invention of A NEW OR IMPROVED APPARATUS TO BE EMPLOYED
IN THE CLASSIFICATION OF COLORS A communication to him from abroad
by Joanny Pittiot of Rue do la Madeleine Lyons in the Republic of France.
COMPLETE SPECIFICATION filed by the said Benjamin Joseph Barnard
Mills at the Office of the Commissioners of Patents on the 13th January
1883.
BENJAMIN JOSEPH BARNARD MILLS of the firm of Harris and Mills of 23
Southampton Buildings in the County of Middlesex, Patent Agent A NEW OR
IMPROVED APPARATUS TO BE EMPLOYED IN THE CLASSIFICATION OF COLORS.
Communicated to me from abroad by Joanny Pittiot of Rue de la Madeleine,
Lyons in the Republic of France.
This apparatus has for its object, by means of some well determined primitive
colors to present to the eye, in such manner as to enable to be separately
observed all the intermediate shades obtained by the mixture in various proportions
of two or a greater number of colors; and at the same time to indicate the exact
proportions of this mixture.
The colors taken for bases will be determined by chemical or physical processes
enabling them to be identically reproduced and the formula which will indicate the
proportion of these colors in any given tint, will perfectly determine this tint which
can be obtained at any time, without preparation, by means of the present
apparatus.
This apparatus is composed of a number of cylinders furnished with pivots
capable of being placed in turn upon a support A. B. Figure 1. where they can
receive a rapid rotary motion by hand or by any convenient motive power: for
this purpose each cylinder C carries a pulley D resting upon a disc or wheel E
the rotary motion of which is transmitted to the cylinder by simple friction.
The primitive colors are printed upon the surface of these cylinders by longi-
tudinal bands of variable widths according to a known law.
The rapid rotation of one of these cylinders by compounding these colors,
presents to the eye a tint progressively varying from one end to the other of the
cylinder of which each transverse section can be separately observed by an open
eye piece F in a screen sliding on a divided rule; the graduation of tho rule will
indicate the position of the tint observed.

page_text: This tint can therefore be exactly represented by the designation of the cylinder
which contains it, and by its position on this cylinder, and it can be mathematically
reproduced wherever there exists a similar wheel or apparatus.
100-
100
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Take for example a cylinder the unrolled surface of which, represented at
Figure 2, contains two colors M and N separated diagonally; and suppose the
length of the cylinder divided into 100 equal parts, any given section a. b. situated
at a distance a from zero of the graduation will contain 100 of the color N, and
of the color M, and its tint will be perfectly designated by the formula
N + (100 x) M which will give not only the means of reproducing this tint,
but also the exact proportions of the primitive colors of which it is formed.
If to the preceding cylinder is added as ropresented at Figure 3 a regular band
of a third color P the width of which is a known fraction for example of the
total surface, the formula which will represent the tint of the section a. b. for
example will be x N + (100 - x) M + 100 P which will also give the proportions
of the three primitive colors employed.
1
There can also be added new regular bands of different colors to obtain the
combinations of 4 or 5 colors.
If instead of separating the colors by a diagonal line as represented at Figure 2,
they are separated by a succession of horizontal lines as represented at Figure 4
formning as many steps as it is desired to interpose of intermediate tints between
the two extreme colors, and if there is given to the eye piece F, Figure 1. the width
of one of these steps, uniform tints can be observed in lieu of graduated tints as in
the first case, which will facilitato greatly the comparison with the samples of tints
to be classified.
The number of cylinders necessary, to reproduce all the combinations 2 and 2,
3 and 3, n and n of the n colors which shall have been chosen for base would be
very great but useless in practice.
Each artist or operative will employ a reduced number of cylinders corresponding
to his ordinary requirements, and will have always, as required, the power of
rapidly creating others for special requirements, by employing a general law
previously established for the arrangement of the colors.
Having thus described the nature of the said Invention and the mode in which
the same is carried into effect I would have it understood that what I claim is
First. The arrangement of an apparatus in which the rapid rotation of a cylinder
or of any other revolving surface, covered with simple colors, serving as types,
and placed in a determined order permits of observing all the shades obtained
by the union of several of these colors, and of comparing them with samples of
tints of which it is required to ascertain the composition, and to reproduce, at
any time, by means of cylinders constructed according to the same law, the exact
shade which has been noted by means of a formula.
Second. The application of this apparatus to the decorative arts, printing, dyeing
and others not only for classifying and designating simply all the shades known,
but also to discover new ones the composition of which is immediately indicated
by the apparatus.
In Witness whereof I the said Benjamin Joseph Barnard Mills have here-
unto set my hand and seal this Thirteenth day of January in the year of
Our Lord one thousand eight hundred and nighty threa