PAPIER-MACHE MANUFACTURE. 203 



to produce the required thickness, the mass is introduced into an oven, 

 or clrying-chamber ; when a core is used, the article with the core still 

 attached is placed in the oven. In twelve hours the drying is completed, 

 and the mass becomes as hard as wood, and of a uniformity of texture 

 seldom found in wood ; it is then cut and turned as required, hollow 

 articles being turned externally while still adhering to this core. In 

 certain cases it is necessary, in order to remove the core, to cut the 

 papier-mache into two symmetrical halves, which are afterwards glued 

 together, again baked, and then turned. The next operation is to rub 

 the articles smooth with pumice and sand-paper, after which they are 

 saturated with a mixture of oil of tar and linseed oil, stoved, lacquered, 

 and ornamented with designs, and are then ready to be gilded or inlaid 

 with mother-of-pearl. 



There are two ways of employing the mother-of-pearl : The first is to 

 soften the shell in water, and while in this state to saw out, by hand, the 

 roiigh form which the ornament is to have, and of a somewhat larger size 

 than it is to appear when subsequently finished. The pieces thus cut are 

 rubbed perfectly even and smooth, and are then imbedded in their proper 

 places on the article, in a thick coat of the tar-varnish, of the consistence 

 of honey, which is employed for the ground upon which the finer varnish 

 is subsequently laid. The article is next placed in the lacquering-stove, 

 and when fully dried is again coated with another coating of the ground 

 varnish, the mother-of-pearl ornaments being also covered, and again 

 stoved. The mother-of-pearl can now be distinguished only by the in- 

 equality of surface which it produces. These inequalities are ground off, 

 by which the mother-of-pearl is fully exposed, its surface being even with 

 that of the rest of the article. The whole is then ready for painting and 

 gilding, and receiving the last coat of fine varnish. 



The second method of inlaying is that patented by Messrs Jennens and 

 Bettridge of Birmingham, and consists in reserving the ornament or 

 design by sketching it with some kind of varnish, not acted upon by acid, 

 upon a piece of the shell ground and polished upon revolving-wheels, as 

 in the other case, and then etching away the surrounding unprotected 

 2 ortions by means of an acid. This process possesses several advantages, 

 one of which is that it is much cheaper than where the design is cut out 

 by hand. 



The process of painting presents nothing peculiar ; but the method of 

 gilding is very ingenious. The part to be gilded is covered with gold-leaf 

 just before the coating of varnish has fully dried, and while it is still 

 adhesive enough to allow of the gold-leaf adhering to it ; upon this gilded 

 surface the ornament, which is to appear in gold, is designed by means of a 

 copal varnish, or of a solution of bitumen, somewhat like Brunswick black, 

 which resists water, but is soluble in oil-of-turpentine. The varnish is 

 then allowed to dry to such a degree as to withstand a slight rubbing, but 

 still to be readily acted upon by a solvent. The superfluous gold is re- 

 moved with a damp cloth, whilst that protected by the varnish remains 



