PAPIER-MACHE 501 



A kind of papier-mache has been introduced, called fibrous slab ; for the preparation 

 of this interesting material the coarse varieties of fibre only are required. These are 

 heated and subjected to much agitation, to secure the reduction of the fibre to the proper 

 size. This being effected, the pulp is removed and subjected to the action of the desic- 

 cating apparatus, or centrifugal drying machine. By the means of this apparatus the 

 water is driven, by the action of the centrifrugal force, from the fibre, and the pulp 

 can thus bo obtained in a few minutes of an equal and proper degree of dryness, and 

 this without the application of any heat. The mass thus obtained may be regarded 

 ns a very coarse mixture. 



This fibrous pulp is next combined with some earthy matter to ensure its solidity, and 

 certain chemical preparations are introduced, for the double purpose of preserving it 

 from the attacks of insects and to ensure its incombustibility. The whole being 

 mixed with a cementing size, is well kneaded together, steam being applied during 

 the process. While the kneading process is going forward, an iron table running 

 on wheels is properly adjusted and covered with a sail-cloth ; this table being arranged 

 to that it passes under an immense iron roller. The fibrous mixture is removed from 

 the kneading troughs, and is laid in a tolerably tiniform mass upon the sail-cloth, so 

 as to cover about one-half of the table ; over this again is placed a length of sail-cloth 

 equal to that of the entire slab, as before. This being done, the table and roller aro 

 set in action, and the mass passes between them. It is thus squeezed out to a per- 

 fectly uniform thickness, and is spread over the whole table. The fibrous slab is 

 passed through the rollers some three or four times, and it is then drawn off upon a 

 frame fixed upon wheels prepared to receive it, by means of which it can be removed 

 to the drying ground. The drying process of course varies much with the tempera- 

 ture and dryness of the air. It does not appear necessary that these slabs should dry 

 too quickly, and there are many reasons why the process should not be prolonged. 



We tried an experiment upon the non-inflammability of this material, by having i 

 fire of wood made upon a slab and maintained there some time. When the ashes, 

 still in a state of vivid combustion, were swept away, the slab was found to be merely 

 charred by the intense heat. Beyond this, a piece of fibrous slab was thrown into 

 the middle of the fire and the flames were urged upon it : under the influence of this 

 intense action it did not appear possible to kindle it into Aflame; it smouldered very 

 slowly, the organic matter charring, but nothing more. 



The Fibrous Slab Company produced a material which, in many of its applications, 

 promised to prove of the greatest utility, while much additional value was given 

 to it from the circumstance of its resisting the attacks of insects, and being non- 

 inflammable. We believe, however, that this manufacture has been discontinued. 



Papier- Mdche may be said, therefore, to consist of three varieties : 1. Sheets of 

 paper pasted together, exposed to great pressure, and then polished ; 2. Sheets of 

 considerable thickness, made from ordinary paper-pulp ; and 3. Such as we have de- 

 scribed in the manufacture of the fibrous slab. E. J. H. 



A new composition was patented, in 1858, by Mr. John Cowdery Martin, which 

 he designated a ' Plastic compound for the manufacture of articles in imitation of 

 wood carvings, &c.' The patentee thus describes his process, and the resulting 

 material : 



' The object I have had in view is the production of a plastic compound applicable 

 to the manufacture of moulded articles, which, when hardened, resembles wood in the 

 closeness of its texture and fibrous character throughout, and is particularly applicable 

 to the manufacture of articles intended to imitate wood-c'arvingw. The new manu- 

 facture may also be called ceramic papier-mache, from the wax-like character of the 

 compound when in a soft state, or before hardening. The compound consists of 

 twenty-eight parts (dry) by weight of paper-pulp, or of any fibrous substances of 

 which paper may be made, reduced to pulp by means of an ordinary beating engine, 

 or other means used for the manufacture of pulp ; twenty parts of resin, or rosin, or 

 pitch, or other resinous substance. I prefer resin or rosin ; ten parts of soda or potash 

 to render the resin soluble ; twenty-four parts of glue, twelve parts of drying oil, and 

 one part of acetate or sugar of lead, or other substance capable of hardening or drying 

 oil. The pulp after leaving the beating engine is to be drained and slightly pressed 

 under a screw or other press, to free it partly from water. The resin and alkali are 

 then to be boiled or heated together and well mixed. The glue is to be broken up in 

 pieces and melted in a separate vessel with as much water as will cover it, and then 

 to be added to the resin and alkali, which mixture is then to be added to the pulp and 

 thoroughly incorporated with it. The acetate of lead well mixed in the oil is then to 

 be added, and the whole mass or compound is then to be thoroughly mixed. The 

 quantity of resin and alkali, in proportion to the glue used, might vary, or glue might 

 even be dispensed with when the acetate of lead would be proportionally increased. 

 After mixing the compound, it is to remain exposed to the air for three or four days 



