ing 36 parts of ash, 27 of sand, and 15 of salt, and ashing over with 20 parts of lead and 10 of tin.

White Glazes. I. Mix intimately 100 parts by weight of white glass, 50 of white sand, 40 of dry, common salt, 120 of plumbic oxide, and 60 of tin ashes.

II. One hundred parts of plumbic oxide, 50 of tin ashes, 100 of white sand, 50 of glass, 10 of common salt, 10 of heavy spar, and 5 to 10 of dry soda. This is more fusible than No. I. Both mixtures furnish a whiter coating the freer the clay is from iron with which the articles are manufactured.

III. Melt together 24 to 25 parts of red lead, 15 to 16 of tin ashes, 36 to 38 of quartz sand, 12 to 14 of potters' clay free from iron, 7 of carbonate of lime, 3 of carbonate of magnesia, and 18 to 20 of calcined soda. The mass, when cold, is comminuted, ground, and sifted.

To Give Earthen-ware or Porcelain a Marbled or Granite Appearance. Dissolve gum tragacanth in water to the consistency of a thick syrup, which will require 3 to 4 days, and add about 10 times its bulk in water to reduce its specific gravity to 1.003. Now prepare a decoction of ounce of seeds of fleabane (Psyllium pulicaria) in 1 gallon of water and mix 1 part of this decoćtion with 5 of solution of gum tragacanth. On account of the high specific gravity of the coloring substances used in the process it becomes necessary to add 1 pound of very thin solution of clay in water to each pound of the mixture, as without this precaution the pigments would not float on the surface of the preparation. The pigmentscolors used under glaze are mostly employed-are triturated with water and kept in special pots until used, when they are mixed with beef gall. To prevent the beef gall from spoiling some carbolic acid is added. Now spatter by means of a brush the different colors mixed with beef gall upon the surface of the mixture of the gum tragacanth, decoction of fleabane seed, and solution of clay. Marbled veins will immediately be formed, which can be worked into imitation of any desired variety of marble by stirring the mass with a horse comb or similar instrument. The articles, which should be rather porous, are dipped into this solution, then

washed to remove the shiny preparation, heated in a muffle, glazed, and treated like common ware. Any variety of decoration can be prepared by painting parts on the surface of the articles with round lake or white lead mixed with gum Arabic, marbling the unpainted spots, and washing of the reserved places; or by impressing copper prints, covering them with round lake, and marbling. If glazed articles are to be marbled pigments rubbed with oil are used. The article must first be coated with dammar resin dissolved in oil of turpentine (13 ounces of resin dissolved in 1 pound of oil of turpentine). After the coating is perfectly dry the article is treated in the same manner as the unglazed. With skill in the manipulation very beautiful articles can be prepared by this process.

GLASS AND OTHER SIGNS.

The following directions for making glass signs are by W. Arrenbrecht:

I. To Etch Glass (Fine-grained). Paint the entire glass, except the parts to be etched, with asphaltum or, best, with ordinary iron lacquer which covers well, and allow it to dry, but not entirely hard, as otherwise the acid is apt to find its way under the iron lacquer. Place a rim of putty, prepared with wax and starch, around the design, care being had that it laps over upon the iron lacquer. Then pour hydrofluoric acid upon the surface, let it stand for 5 minutes, pour it back into the flask, and wash the entire surface with water. Then remove the asphaltum with oil of turpentine and wash again with white soap and water.

II. To Etch Glass (Coarse-grained). Proceed in the same manner as above, but throw emery into the acid immedi ately after it has been poured upon the surface; let it remain for 5 minutes, then pour it back into the flask and wash and cleanse as above.

III. Gilding Glass. Polish the glass thoroughly with whiting and then with a linen rag dipped in alcohol. Prepare a size by boiling 2 ounces of isinglass in sufficient water to cover it, and, when dissolved, add 1 quart of alcohol, and then dilute to 2 quarts with water, and

filter. Flood the surface to be gilded with the size, lay the gold leaf flat on it, and scatter elutriated chalk (whiting) previously warmed over the whole. Should the chalk form lumps in heating, rub it fine, but the dusting over with chalk must be delayed until the gold leaf is dry. When the gold leaf is entirely dry dust it off with a fine brush and then polish it with a piece of silk velvet. Repeat the gilding once more, and then back all the gold which is to remain with copal or dammar lacquer. When this is dry remove the superfluous gold by rubbing with the moistened finger.

IV. Silvering on Glass is done in the same manner as gilding, but somewhat more isinglass is used, as the silver leaf being softer than gold leaf requires a stronger agglutinant.

V. Gilding on Show Windows. The same solution of isinglass given under III. is used. Cover the surface to be gilded with the mixture and lay on the gold obliquely. When dry, polish the gold with a rag of silk velvet and repeat the operation.

VI. Correcting the Isinglass Mixture. If, after the second polishing, stains should make their appearance in the gold, the solution contains too much isinglass and must be diluted by adding distilled water and rectified alcohol. But if the gold cannot be polished the mixture contains too little isinglass. It is therefore advisable to first test the solution upon a piece of glass.

VII. Backing the Inscription on Show Windows. After rubbing off the superfluous gold with the finger apply to the entire inscription a coat of good oil paint mixed with some hemp oil and English carriage lacquer, which will preserve the inscription even upon panes covered with sweat, and its durability can be guaranteed for years.

VIII. Backing Glass Signs without Shades. After rubbing off carefully the superfluous gold with the finger apply 2 coats of Frankfort black rubbed up in oil to the entire back of the glass and inscription.

IX. Backing Glass Signs with Shades. Apply 2 coats of the same black, but leave the shades free. When the black is dry, paint the places left for the shades with red, green, blue, etc., oil paint.

X. With Mother-of-pearl Insertions. Gild in the manner given above. When the gold is dry, coat only the outlines of the inscription with copal or dammar lacquer. After carefully removing the superfluous gold apply 2 coats of the mentioned black oil paint, leaving free the inner part of the inscription, etc., for the mother-of-pearl. If the inscription is to be shaded proceed in the same manner as given under IX.

XI. Mother-of-pearl Insertions. Very thin lamina of mother-of-pearl of different colors are used. Select suitable pieces, and, if too large, break them in two. Then coat first the places left free in the inscription with dammar lacquer, and then one side of each of the pieces of mother-of-pearl; lay them on the inscription and press them gently down with the handle of the brush, continuing thus until the entire surface is covered. Do not place the pieces close together, but leave small inter-stices between them, which are afterward filled up with lacquer and pulverized oyster shells or other shells dusted in.

XII. Backing with Tinfoil is done in the same manner as with mother-ofpearl, except that the oil paint is not allowed to dry entirely, but to remain just sticky enough to fasten the tinfoil by a gentle pressure, care being had to place the glossy side of the tinfoil upon the glass.

Transparent Glass Sign (Child's American Patent). Coat a glass plate with paint so that the places to be transparent remain free. Back this glass plate with a second, and fill the space between them with pieces of colored glass of irregular sizes. By illuminating the sign from the back a wonderful effect is produced. Further, the filling of such a sign could be set in motion by a suitable apparatus, thus producing a kaleidoscopic effect.

Sign Painting. It may be laid down as a general rule for all Roman capitals, except I, J, M, and W, that the extreme breadth should equal the height; the breadth of I and J is equal to half the height, and that of M and W to 1 times the height. Gilt letters are written with Japan size, a substance which soon acquires such a state, between dryness and wetness, that leaf gold laid

several days in thin lime and replace it in the basket to drain, and wash off with clean water and dry. This steeping in lime-water is of the utmost importance, as the quality of the glue is mainly dependent upon it. Too much steeping yields a small quantity of glue, but of an excellent quality, while that obtained from glue stock steeped only for a short time is dark.

It is best to store fresh or undried glue stock during the winter in wooden or brick vats containing dilute limewater, well stirred when putting in the

waste.

The glue boiling, which is best done in the open air, is commenced in spring, as soon as the weather permits. This can be done with wet and with dry waste.

Boiling with wet waste is done by covering glue stock in a vat with water and allowing it to soak for 12 hours, then drained, and all signs of lime washed off. It is then piled in heaps and exposed to the air for 12 to 24 hours to evaporate the acrid constituents. It is now boiled, the work being commenced as early in the morning as possible.

be sufficiently steeped in lime, washed, and dried.

The actual boiling is done in a copper or iron boiler (Fig. 13), which, if 250 pounds of glue are to be manufactured, should be large enough to hold at least 275 gallons of water. It should be somewhat shallower than its width, and should have a double bottom bent inwards in order to offer greater resistance to the fire. It should be further provided with a discharge pipe and cock, through which the fluid glue is drawn off. Upon the bottom of the boiler is a perforated bottom of sheet iron or copper, to prevent the waste from lying immediately upon the bottom, and burning.

It is an easy matter to procure all the warm water which may be required by utilizing the waste heat for heating water in a reservoir erected in the direction in which the gases of combustion escape. It is placed higher than the boiler so that the warm water can be readily drawn from it into the latter (see Fig. 13).

When everything is in proper shape,

the top of this a sufficient quantity of waste to fill the boiler. If this holds 275 gallons, about 125 gallons of clean water are added, if wet material is used, and about 225 gallons to dry stock. The mass is now boiled until a sample taken from the boiler cools to a jelly. This, for wet material, requires generally 1 hour; for dry stock, 2 hours. The glue will be ready for cutting when a sample, poured into a cup, can be conveniently taken out when cold. The fluid is then drawn off into the cooling vat (clarifying vat). This is also provided with a discharge pipe and cock and placed high enough to allow of a bucket being conveniently put under it. When the glue has become clear it is drawn off and poured into boxes (moulds).

A fresh quantity of waste is added to the material remaining in the boiler, and boiled. This is called the second boiling, and is treated in the same manner as the first.

The residue remaining in the boiler after the second boiling is boiled until the fluid forms glue. This is called the third boiling. The product is treated in the same manner as the foregoing.

The residue from the third boiling is used for preparing the so-called gluewater. This is made by pouring in enough water to cover the residue in the boiler from 2 to 3 inches deep, and boiling about 2 hours, until all glutinous substances have been dissolved. This fluid is too weak to form glue. It is added to the next boiling of glue stock, to accelerate the process.

Clarifying the Glue. This is done either with alum or white of egg. Pulverize 2 to 4 pounds of alum for every 200 pounds of glue, and dissolve it in 50 pounds of boiling glue taken from the boiler. Add this solution to the mass in the boiler, and let the whole boil for 10 minutes longer, when the clarified glue is drawn off into the cooling vat. The glue may also be clarified by dissolving for every 100 pounds of glue pound of purified borax finely powdered and 3 ounces of purified potash in boiling glue, and pouring this into the fluid in the boiler. To Color the Glue Yellow. For every 100 pounds of glue to be colored dissolve 1 to 2 pounds of finely-powdered

crystallized soda in boiling glue, and stir this into the boiler until a uniform yellow color is obtained.

To Whiten the Glue. For every 100 pounds of glue add 2 pounds of sugar of lead completely dissolved in a hot solution of glue. Mix it thoroughly with the glue in the boiler, and then add 2 pounds of pulverized white vitriol (sulphate of zinc) also dissolved in boiling glue.

Pouring into the Boxes (Moulds). This is done as soon as the glue has

Fig. 14.

been boiled, sufficiently cooled, and clarified. The boxes (Figs. 14, 15) are

Fig. 15.

made of pine, and are generally 4 feet long, 84 inches wide, and 6 inches high. They should be very smooth inside and water-tight. Before the glue is poured into them they should be kept filled for 1 day with fresh milk of lime. This is called freshening the boxes. In the spring the boxes should be given a coat of pure linseed oil, which will facilitate the removal of the congealed glue.

The operation of pouring the glue into the moulds is a very simple one: A funnel (Fig. 16) with a flat bottom reaching over the edges of the mould sits so firmly upon them as to need no support from the workman. In the funnel is a small sieve (Fig. 17) of horsehair, which keeps back any impurities in the glue. When the first