370 MOTHER-OF-PEARL 



depth, eight feet in length, and two feet wide, including the cost of wool, and the pay- 

 ment for labour, is little short of 8001. When, however, it is known that these threads 

 are subsequently cut into the length required to form the rug, and that these lengths 

 are but the three-sixteenths of an inch in depth, it will be evident that the number of 

 these beautiful carpets which can thus be obtained renders the manufacture fairly re- 

 munerative. The boxes into which the rugs are placed are fixed on wheels, and they 

 have moveable bottoms, the object of which will be presently understood. From the 

 upper part of the immense building devoted to carpet manufacture, in which this 

 mosaic rug-work is carried on, we descend with our rug to the basement story. Hero 

 wo find, in the first place, steam chests, in which india-rubber is dissolved in cam- 

 phine. It may not be out of place to observe that camphine is actually spirits of tur- 

 pentine, carefully rectified, and deprived of much of its smell, by being' distilled from 

 either potash or soda. Eecently-prepared camphine has but little of the terebinthi- 

 nous odour, but if it is kept long, and especially if it is exposed to the air, it again 

 acquires, with the absorption of oxygen, its original smell. This is of course avoided 

 in the manufacture of such an article as an hearth-rug as much as possible. The 

 camphine is used as fresh as possible, and in it the india-rubber is dissolved, until we 

 have a fluid about the consistence of, and in appearance like, carpenter's glue. 



In an adjoining room were numerous boxes, each one containing the rug-work in 

 some of the stages of manufacture. It must now be remembered that each box re- 

 presents a completed rug the upper ends of the thread being shaved off, to present 

 as smooth a surface as possible. In every stage of the process now all damp must 

 be avoided, as wool, like all other porous bodies, has a tendency to absorb and retain 

 moisture from the atmosphere. The boxes, therefore, are placed in heated chambers, 

 and they remain there until all moisture is dispelled ; when this is effected, a layer of 

 india-rubber solution is laid over the surface, care being taken in the application 

 that every thread receives the proper quantity of the caoutchouc ; this is dried in the 

 warm chamber, and a second and a third coat is given to the fibres. While the last 

 coat is being kept in the warm chamber, free from all dust, sufficiently long to dis- 

 sipate some of the camphine, the surface on which the rug is to be placed receives 

 similar treatment. In some cases ordinary carpet canvas only is employed ; in 

 others, a rug made by weaving in the ordinary manner is employed, so that either 

 side of the rug can be turned up in the room in which it is placed. However this 

 may be, both surfaces are properly covered with soft caoutchouc, and the ' backing ' is 

 carefully placed on the ends of worsted forming the rug in the box. By a scraping 

 motion, the object of which is to remove all air-bubbles, the union is perfectly 

 effected ; it is then placed aside for some little time, to secure by rest that absolute 

 union of parts between the two india-rubber surfaces which is necessary. The 

 separation of the two parts is after this attended with the utmost difficulty ; the worsted 

 may be broken by a forcible pull, but it cannot be removed from the india-rubber. The 

 next operation is that of cutting off the rug; for this purpose a very admirable, but a 

 somewhat formidable machine is required. It is in principle, a circular knife, of 

 twelve-feet diameter, mounted horizontally, which is driven by steam-power, at the 

 rate of 170 revolutions in a minute. 



The rug in its box is brought to the required distance above the edge of the box 

 by screwing up the bottom. The box is then placed on a rail, and connected with a 

 tolerably fine endless screw. The machine being in motion, the box is carried by the 

 screw under the knife, and by the rapid circular motion, the knife having a razor-liko 

 edge, a very clean cut is effected. As soon as the rug is cut off to the extent of u 

 few inches, it is fastened by hooks to strings which wind over cylinders, and thus 

 raise the rug as regularly as it is cut. This goes on until the entire rug is cut off to 

 the thickness of three-sixteenths of an inch. The other portion in the box is now 

 ready to receive another coating, and the application of another surface, to form a 

 second rug, and so on, until about one thousand rugs are cut from the block prepared 

 as we have described. 



MOSS AGATE, or MOCHA STONE. A variety of chalcedony enclosing 

 dendritic or moss-liko markings of an opaque brownish-yellow colour, which are pro- 

 duced by oxide of manganese or iron. It was the dendrachates of the ancients. 



MOTHER-OF-PEARXi (Nacre de Perles, Fr. ; Perlenmuttcr, Ger.) is the 

 hard, silvery, brilliant internal layer of several kinds of shells, particularly oysters, 

 which is often variegated with changing purple and azure colours. The large oysters 

 of the Indian seas alone secrete this coat of sufficient thickness to render their shells 

 available to the purposes of manufactures. The genus of shell-fish called PentadincB 

 furnishes the finest pearls, as well as mother-of-pearl ; it is found in greatest per- 

 fection round the coasts of Ceylon, near Ormus in the Persian Gulf, at Cape Comorin, 

 and among some of the Australian seas. The brilliant hues of mother-of-pearl do 

 not depend upon the nature of the substance, but upon its structure. The microscopic 



