52 ANNUAL OF SCIENTIFIC DISCOVERY. 



There are at present five principal varieties of papier macJie 

 known in the trade, viz. : 1. Sheets of paper pasted together upon 

 models. 2. Thick sheets or boards produced by pressing ordinary 

 paper pulp between dies. 3. Fibrous slab, which is made of the 

 coarse varieties of fibre only, mixed with some earthy matter, and 

 certain chemical agents introduced for the purpose of rendering the 

 mass incombustible ; a cementing size is added, and the whole well 

 kneaded together with the aid of steam. The kneaded mass is passed 

 repeatedly through iron rollers, which squeeze it out to a perfectly 

 uniform thickness ; it is then dried at a proper temperature. 4. Car- 

 ton pierre, which is made of pulp or paper mixed with whiting and 

 glue, pressed into plaster piece-moulds> backed with paper, and, when 

 sufficiently set, hardened by drying in a hot room. 5. Martin's Cera- 

 mic papier mache, a new composition, patented in 1858, which con- 

 sists of paper pulp, rosin, glue, drying oil, and sugar of lead, mixed 

 in certain fixed proportions and kneaded together. This composition 

 is extremely plastic, and may be worked, pressed, or moulded into 

 any required form. It may be preserved in this plastic condition 

 for several months by keeping the air away, and occasionally knead- 

 ing the mass. 



The first-mentioned variety of papier maclie alone engages our at- 

 tention here. A special kind of paper, of a porous texture, is manu- 

 factured for this purpose. An iron mould of somewhat smaller size 

 than the object required is greased with Russian tallow, a sheet of 

 the paper is laid on to the greased surface of the mould, and covered 

 over with a coat of paste made of the best biscuit-flour and glue, 

 which is spread evenly all over the sheet with the hands; another 

 sheet is then laid on, and rubbed down evenly, so that the two sLeets 

 are closely pasted together at all points. After this the mould is taken 

 to the drying chamber, where it is exposed to a temperature of about 

 one hundred and twenty degrees ; when quite dry, which it takes sev- 

 eral hours to accomplish, it is carried back to the pasting-room, and 

 another sheet laid on w r ith another coat of paste, after which it is 

 returned to the drying chamber ; and the same operation is repeated 

 over and over again, until sufficient thickness is attained, which, for 

 superior articles, such as are manufactured at these works, requires 

 from thirty to forty sheets of paper, and of course as many coats of 

 paste between. The shell is then removed from the mould, and planed 

 to shape with a carpenter's plane, after which it is dipped in linseed 

 oil and spirits of tar to harden it ; this changes the color from gray 

 to a dingy yellowish-brown tint. The article is then stoved, and seven 

 or eight coats of varnish are laid on (with a stoving after each), which 

 are cleared off each time, any inequalities of surface being finally 

 removed with pumice-stone. The number of drying processes the 

 articles have to go through consume so much time, that it takes three 

 or four weeks to fit them for ornamentation, which is applied in 

 bronze-powder, gold or color, and for many articles also in mother- 

 of-pearl. The ornamentation of these articles is sometimes effected 

 in the highest style of the painter's art. 



The gold-leaf is laid on with a solution of isinglass in water, the 

 design then pencilled on with asphaltum, the superfluous gold re- 

 moved with a dossil of cotton dipped in water, which leaves intact 



