CAOUTCHOUC 697 



pieces were found cohering together into a mass, this being cut showed a mottled 

 grain, but being replaced and subjected to the revolving teeth of the rollers, it 

 became very hot ; and was found to be uniformly smooth in texture when cooled and 

 cut open. 



The first charge was about 2 ounces of rubber, and required the power of a 

 man to work it. The next machine soon formed a soft solid, with speed and power, 

 from all kinds of scraps of India-rubber, cuttings of bottles, lumps, shoes, &c. : a charge 

 of 1 Ib. gave a smooth uniform cylindrical lump of about 7 inches in length and 1 

 inch in diameter. This process, including the use of heated iron rollers, was long 

 kept secret ; it is now known as the masticating process, and the machines are called 

 ' Masticators.' In the works at Manchester the charges are 180 Ibs. to 200 Ibs. 

 of India-rubber each, and they produce, by steam-power, single blocks 6 feet long, 

 12 or 13 inches wide, and 7 inches thick. The Mammoth machine of Mr. Chauffee, 

 in the United States, weighs about 30 tons, and appears to have been invented about 

 1837. It is a valuable machine, differing in construction from Hancock's masticators, 

 but it answers well in many respects ; it may be considered as the foundation of the 

 American trade. 



In 1820 the blocks were cut into the form of square pieces and sold by the 

 stationers to rub out pencil-marks, and then thin sheets were introduced for a variety 

 of purposes. A cubical block cut by a keen sharp blade kept constantly wet, gave a 

 sheet of India-rubber; the block raised by screws and the knife guided, enabled 

 sheets of any thickness to be cut, sometimes so even and thin, as to be semi-transparent ; 

 when warm, the small sheets could be joined edge to edge, and thus large ones pro- 

 duced. From the blocks, rollers of solid rubber could bo made, cylinders were covered 

 for machinery, billiard tables had evenly cut pieces adjusted, tubes and vessels for 

 chemical use were employed, and constantly increasing trials were made of the masticated 

 rubber. 



These remarks upon the early and successful manufacturers will better enable the 

 outline of improvements to be followed. It can readily be imagined that when capital 

 and interest combined to meet the changing requirements of the public, the trade 

 applications became more numerous ; many of these were secured by patents, but very 

 many were worked as secret processes. 



The department of operative industry which embraces caoutchouc manufactures 

 has, within a few years, acquired an importance equal to that of some of the older 

 arts, and promises, ere long, to rival even the textile fabrics in the variety of 

 its designs and applications. The manufacture of caoutchouc has, at present, these 

 principal branches: 1. The condensation of the crude lumps or shreds of caout- 

 chouc, as imported from South America, India, &c., into compact homogeneous 

 blocks, and the cutting of these blocks into cakes or sheets for the stationer, surgeon, 

 shoemaker, &c. 2. The filature of either the India-rubber bottles, or the artificial 

 sheet caoutchouc, into tapes and threads of any requisite length and fineness, which, 

 being clothed with silk, cotton, linen, or woollen yarns, form the basis of elastic 

 tissues of every kind. 3. The conversion of the refuse cuttings and coarser qualities 

 of caoutchouc into a viscid varnish, which, being applied between two surfaces of 

 cloth, constitutes the well-known double fabrics, impervious to water and air ; and by 

 special applications to one surface, constitute the single-texture fabrics. 4. The 

 vulcanisation of India-rubber. 5. The mechanical applications resulting from the 

 changed India-rubber. 6. The solarisation of caoutchouc. 



The caoutchouc, as imported in skinny shreds, fibrous balls, twisted concretions, 

 cheese-like cakes, and irregular masses, is, always more or less, impure, but some- 

 times it is fraudulently interstratified with earthy matter. It is first cleansed by being 

 cut into small pieces, and then washed in warm water. It is next dried on iron trays, 

 heated with steam, while being carefully stirred about to separate any remaining dirt, 

 and is then passed through a pair of iron rolls, under a stream of water, whereby 

 it gets a second washing, and becomes at the same time equalised by the separate 

 pieces being blended together. The shreds and cuttings thus laminated, if still foul 

 or heterogeneous, are thrown back into a kind of hopper over the rolls, set one-sixteenth 

 of an inch apart, and passed several times through between them. 



In the establishment of William Warne and Co. at Tottenham, rinsing and lamina- 

 tion are superseded by a process of washing practised in Mr. Nickels's second opera- 

 tion, commonly called the grinding, or, as it should more properly be styled, the kneading. 

 The mill employed for agglutinating or incorporating the separate fragments and shreds 

 of caoutchouc into a homogeneous elastic ball, is a cylindrical box or drum of cast iron, 8 

 or 9 inches in diameter, set on its side, and traversed in the line of its horizontal axis 

 also 8 or 9 inches long) by a shaft of wrought iron, furnished with 3 rows of pro- 

 jecting bars, or kneading arms, placed at angles of 120 deg. to each other. These act 

 by rotation against 5 chisel-shaped teeth, which stand obliquely up from the front 



