Improvements in the Mosaic Reproduction of Decorative Painting.
Year: 1893

page_text: Date of Application, 5th May, 1893
Complete Specification Left, 3rd Feb., 1894-Accepted, 10th Mar., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by ANTOINE JUMEAN, of 2, Rue Vandamme, Paris,
in the Republic of France, Artist in Mosaics.]
Improvements in the Mosaic Reproduction of Decorative Painting.
I, HENRY HARINGTON LEIGH, Assoc. M. Inst. C.E., Fel. Ch. Inst. P.A.,
F.I. Inst., practising as Phillips & Leigh at 22 Southampton Buildings, Chancery
Lane, W.C., Engineer and Patent Agent, do hereby declare the nature of this
invention to be as follows:-
The present invention relates to improvements in the mosaic reproduction of
decorative painting.
In carrying it into effect a tracing or replica of the picture or an outline of the
scene to be reproduced is prepared, and the several areas of the same tint are each
outlined round and marked with a mark common to them all but distinctive with
respect to other areas. A tracing of the above outlines and marks is next taken,
and from it they are traced down on or otherwise transferred to or reproduced
upon a slab of plaster or other suitable material. The outlines and marks are
lightly cut into the slab, but this cutting may be omitted if the colourist chooses,
the object of it being only to prevent masses of different tints affecting each other.
Each area outlined as above described must be quite separate from its neighbours
and, if desired, any one may be hollowed. The slab must then be greased. The
colours employed are powdered colours mixed up with white cement in proper
proportion to give the required tint; and these should be prepared beforehand and
be ready in suitable receptacles marked with the respective area marks. Each
area is then filled in with its appropriate tint to a depth from 2 to 3 millimetres.
When the colours are set, the surface is roughened and cement is poured over
it till the desired thickness is attained. The mosaic is then taken off the slab
and any convexities or ridges which may have been formed on its under side
by the engraved lines or the hollows in the slab are removed and the mosaic is
polished.
The invention does not limit me in respect of the materials which are to be used
in the preparation of the mosaic, for these may be varied.
Dated this 5th day of Mar 1893
HENRY H. LEIGH.
COMPLETE SPECIFICATION.
Improvements in the Mosaic Reproduction of Decorative Painting.
I, HENRY HARINGTON LEIGH, Assoc. M. Inst. C.E., Fel. Ch. Inst. P.A.,
F.I. Inst., practising as Phillips and Leigh at 22 Southampton Buildings,
Chancery Lane, London, W.C., Engineer and Patent Agent, 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 :-
The process of mosaic reproduction which, with the resultant mosaic, are the
subject matters of the present invention and application for Letters Patent,
reproduces decorative painting in any of its forms exactly, such as, for instance,
decorative panels, arabesques, landscapes, flowers, fruits, birds, portraits figure
paintings, etc.

page_text: .
:
It consists of slabs formed of two layers, one of the latter being plaster and the
other one composed of portions of mixed cement and colour, the latter layer being
the actual mosaic.
The accompanying sheet of drawings (which is to be taken as part of this
Specification and read therewith) represent the mosaic as well as the plaster
moulding slab used in the production of it, and the original of the mosaic. The
latter is a decorative fancy cross printed by chromo lithography.
Figure 1 represents the chromolithograph original.
Figure 2 is an elevation of the plaster moulding slab which is used in the
production of the mosaic.
Figure 3 is a vertical section along the line x-x of Figure 2.
Figure 3 is a similar section of a modified form of slab.
Figure 4 is a similar section of the slab and the mosaic.
Figure 5 is an elevation of the finished mosaic before it has been polished.
The process of manufacturing mosaics by the present invention is as follows.
1st step. Upon a chromolithograph L, or other equivalent representation of the
before mentioned cross, the artist begins by separating, by lines drawn with a pen,
the various tints and shades, red, blue, white, yellow and grey, one from the other.
The depth of the lines varies with the depth of the colours.
2nd step. All the shades of the chromolithograph L, having thus been separated
by the pen lines, all the areas of the same shade are marked with the same
mark, no matter what, letter, figure, or arbitrary sign. Suppose that each
colour appears in, say, ten shades. A clear or light shade of grey receives a G;
a darker shade of the same colour, G ; and a nearly black grey where
the frame is in shadow, G
The clear yellow of the central ring of
the cross is marked J; the darker shade of yellow around the arms of the
cross, J.
The same with the red shades R. . . and R.
Clear white is marked W.
blue shades B
and B
; the
3rd step. All the lines and signs made as above described on the chromolithograph,
are transferred to a sheet of transfer paper. This latter will be a duplicate of
Figure 1. It is placed. face downwards upon a slab M of plaster or some other
material which can be engraved, and all the lines and marks are traced down into
the plaster with a suitable style...
4th step. Having after the 3rd step, all the lines and marks drawn upon the
plaster slab, each one is engraved or incised to from a quarter to a third of a
millimetre wide and to the same depth. These dimensions are not absolute and
may be varied in either direction as may be required. The engraving or incising
may even be omitted, if the artist is clever enough to stop the flow of his colours
without these small trenches, in which case a line only, without engraving, will
suffice; but, even then, it is of the first importance that the lines shall shew up
clearly upon the plaster slab for the latter is destined to serve as the basis of the
mosaic. To further this purpose, the slab may receive a coat of gum lac and the
principal lines be blacked up with Indian ink, after which a second coat of gum
lac may be applied.
5th step. Each area separated from its neighbour as already explained by an
engraved line, will be really independent or isolated. If it is considered advisable
for the purpose of assisting an inexperienced artist, the areas may be, previous to
the application of the gum lac, hollowed a little, great care however being taken
not to touch the sides of the engraved lines or to, in any way, alter their contour.
This is indicated in Figure 3^.
a is the flat surface of the moulding slab. M.
c, c are the engraved lines or trenches which separate the areas from each other.
b, bare the hollowed surfaces of the areas already described both as to purpose
and mode of formation.
6th step. The moulding slab M obtained in the way described above may as a
preliminary, have its surface lightly greased, to facilitate parting. The colours
(that is to say, colours in powder, mixed with white cement in powder and in the

page_text: desired proportions to give the different tints or shades corresponding with the
area marks) must be prepared beforehand and placed in pans arranged in a nest or
divided tray in such a way that the artist shall have only to temper his coloured
cement without fumbling about. Each box is marked with the area mark
corresponding with the shade which it contains.
Let it be supposed that the artist begins with the yellow areas. Ho turns to
the colour pan which holds the shade corresponding with that marked J on the
chromo, tempers as much as he judges to be necessary, in a suitable vessel, and fills
all those areas on the moulding slabs M which are marked with a J. In the case
illustrated, there is only one J area, the annular one in the middle of the cross.
This deposit of yellow cement is built up to a height of from 2 to 3 millimetres ;
suitable modelling tools being used for the purpose. The artist then passes to the
mark J... for which he proceeds in the same way as with the mark J. All the
other marks B, R, W, G, etc., are dealt with in the same way, great care being
taken not to overstep the boundaries of the respective areas, a blunder which will
be all the more easily avoided if the artist has taken the precaution to hollow the
areas in the way described with reference to the 5th step.
7th step. When all the areas have been filled with coloured cement, the artist
must wait for it to set sufficiently. The back of it is pricked so as to roughen it,
and a layer of ordinary cement is poured upon it. Thanks to the roughnesses, the
backing and filling cement-II, Figure 4-adheres to the mosaic-1, Figure 4,-
and gives the desired thickness to the latter. C-Figure 4-is a frame fitted upon
the plaster slab M to prevent the cement and plaster running over.
8th step. When it is judged that the cement and plasters have set, the mosaic in
question is taken off the moulding slab, the parting being effected quite easily by
reason of the layer of grease between the said slab and the mosaic. The artist has
then, in cement mosaic, a replica or reproduction of the chromolithograph as exact
as mosaic art can yield.
9th step. In the replica obtained in the manner described above, if use has been
made of the graver in the way described in the 4th step, and of the hollows
described in the 5th step-the engraved lines as well as the areas being sunk in the
moulding slab-the said lines and hollows will shew in relief on the mosaic. They
are removed by pumice stone or by any other known suitable means, and the
surface of the mosaic polished up in any of the ways well known for polishing
marbles or cements, or it may be varnished, hot or cold, as may be desired.
The above described process is thus seen to produce a beautiful replica of the
cross of the chromolithograph and the cost of it is only about a thirtieth or even a
sixtieth of that of a mosaic in marble or stone by any other system.
It is evident that it is possible to obtain, by the process described above, mosaics
of figure pictures or those of any subjects, animals, flowers, landscapes etc. By
carefully distinguishing the shades of the colours, or in other words, by multiplying
the areas, the artist will succeed in producing mosaics exactly resembling his originals
chromolithographed or otherwise.
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
A mosaic consisting of two layers, viz., a layer consisting of blocks of coloured
cement and a layer of ordinary plaster adapted to serve as a base or backing for
the former.
Dated this 3rd day of February 1894.
HENRY H. LEIGH,
Chartered Patent Agent.