Inventions are now being developed by which mosaics can be cheaply worked, which, of course, while the work does not compare in merit to that of Italy and Russia, is at the same time suitable for many purposes of domestic ornamentation.
The contrivance shown in Figs. 255 to 258 is the invention of Mr. Robert Eltzner, of New York City, and is for the manu facture of mosaic plates for pavements, wall ornamentation, furniture, and other decorative purposes from natural and arti ficial material, such as marble, slate, porcelain, majolica, glass, jet, wood, and the like, so that any desired design can be pro duced without the employment of especially skilled hands, and thus very ornamental articles be furnished at reasonable prices for application in the arts.
The invention consists of a mosaic tablet or plate, the indi vidual blocks of which are arranged face downward, according to a pattern or design on transparent paper that has been placed between two glass plates, so that light can fall through from below. The blocks of mosaic which form the plate are finally backed by means of a cement, leaving open joints, and stiffened with and exterior strip or band, as will appear more fully hereafter.
Fig. 255 represents a perspective view of the table on which the mosaic plate is formed. Fig. 256 is a detail vertical trans verse section of the same. Fig. 257 is a detail side view of a portion of the table, both figures being drawn on an enlarged scale, and Fig. 258 is a plan view of a mosaic plate formed on a table.
In carrying out the invention, a table A, of the size of the mosaic plate to be formed, is supported on a suitable stand B. The table A is made of an exterior iron frame and of two glass plates a and b, between which is placed the drawing of the design which is to be produced in mosaic. The design is made on transparent or translucent tracing-paper, which is placed between the two glass plates with the face side down ward, and secured by gum to the lower glass plate b. The thickness of the covering glass plate a increases with the size, weight, and thickness of the mosaic tablet to be produced. Upon the top glass plate a, a rectangular frame of upright glass strips c is placed, the corners of which are held together by stout paper strips pasted thereto. Below the glass strips c is placed a layer of paper, which covers the glass plate a outside of the glass strips c, so as to protect the surface of the former. Outside of the vertical glass strips c are arranged flat rubber strips d, also intermediate r ,bber strips dl, a" between the glass plates a b and frame Al, the rubber strips di, el', and the clamps e, which are applied near the corners of the frame Al, holding the glass plates firmly in position upon the iron frame of the table. The vertical glass strips c vary in height according to the thickness of the mosaic plates to be formed, and serve as the exterior walls for the cement backing which is given to the mosaic plate. A strip or band f, of galvanized wire-gauze, is placed in position along the inner surface of the glass strips, as shown in dotted lines in Fig. 256. The band f should not ex tend lower down than the depth of the joint between the blocks of the plates, for which purpose, so as to obtain the correct position of the band f, a flanged zinc strip fl is placed upon the glass plate a, below the rubber strips d, the zinc strips ex tending below the glass strips c c to the inside, its flange pro jecting upward along their inner surface for supporting the band f, as shown in Fig. 256. The individual blocks of mosaic, whatever be the material employed, are now placed in position upon the covering glass plate a, according to the design repre sented on the tracing-paper between the plates b a. As the
light passes through the glass plates from below, it renders the configuration and colors of the design clearly visible, so that the exact position and color of the blocks required are clearly recognized. One row after the other, from the left to the right, is successively placed in position, the faces of the blocks being gummed, so that they adhere to the glass plate. If it be de sired to bring out some portions of the design in relief, the remaining portions have to be covered with square glass plates of the size of the block, so that the blocks placed thereon are set somewhat below the blocks without glass plates. When all the blocks are placed in position according to the design, the covering plate a, with the blocks remaining thereon, face down wards, is removed from the frame for being backed and finished, while the table itself is ready for forming the next mosaic plate. For finishing the mosaic plate, the open joints between the blocks are now partly filled up with a layer of fine sand to the depth of the joints. As soon as this is done, a backing gl of a proper cement, plaster-of-paris, or other suitable material, is spread into the joints and over the back of the blocks until they are covered to the thickness of one-eighth to one-quarter of an inch. A layer gl of wire-gauze is placed upon the cement and imbedded therein, after which it is covered with a thick layer of cement, plaster-of-paris, or other material, to which, according to the thickness of the plate, sand or small lumps of stone are added. As soon as the cement backing has suffi ciently set, the clamping-screws are unscrewed, the paper strips at the corners of the glass strips c cut through, and the latter removed. The mosaic plate is then lifted off from the glass plate a, and placed face upward on a suitable setting-plate for final drying. The joints are then cleared of the adhering sand by means of a brush, and the mosaic plate is finished.
If desired, the blocks may be connected in a still more re liable manner by means of short metallic strips, which are cast in by the cement between the blocks, or by other means, as wished. In this connection it may be mentioned that the proper size of the working-table to be used is preferably equal to four square feet, so that four mosaic plates each one square foot in size may be made at the same time, the separation of the plates being readily obtained by means of a dividing-cross of glass strips. If larger mosaic plates are desired, larger working tables' may be used. The frame of the table is preferably con nected to the supporting stand by means of a hinged joint and semicircular guide-rails, so as to be set into into inclined posi tion, by which the passage of the light through the design is facilitated. If extra large and heavy mosaic plates It are to be made, the lower glass plate b is made of several pieces, between which iron stiffening-rails are interposed.
The advantages of this improved method of manufacturing mosaic plates are that any desired design may be quickly pro duced without the employment of skilled hands, and that a number of persons can be employed at the same time to pro duce different plates. The plates can be made by daylight or artificial light, provided the colors on the design can be prop erly distinguished. As the joints between the blocks are open, a secure foothold is furnished when used for pavements. The plates do not require to be made of any great thickness, as the inclosing band and interposed layer of wire gauze in the back ing impart to them considerable strength and thickness.