488 PAPER, MANUFACTURE OF 



course of the stuff ; the spindle upon which each cylinder, c, mores, extending across 

 the engine, and being put in motion by a band-wheel or pinion at the point, B. 

 One cylinder is made to traverse at a much swifter rate thau the other, in order 

 that the rags may be the more effectually triturated. The cylinders, c, as shown in 

 the vertical section, are furnished with numerous cutters, running parallel to the axis, 

 and again beneath them similar cutters are mounted (D) somewhat obliquely, against 

 which, when in motion, the rags are drawn by the rapid rotation of the cylinders, 

 and thus reduced to the smallest filaments requisite, sometimes not exceeding the 

 sixteenth of an inch in length ; the distance between the fixed and moveable blades 

 being capable of any adjustment, simply by elevating or depressing the bearings 

 iipon which the necks of the shaft are supported. When in operation, it is of course 

 necessary to enclose the cylinders in a case, as shown, BE, otherwise a large proportion 

 of the rags would, inevitably, be thrown out of the engine. The rags are first worked 

 coarsely, with a stream of water running through the engine, which tends effectually 

 to wash them, as also to open their fibres ; and in order to carry off the dirty water, 

 what is termed a washing drum is frequently employed, consisting simply of a 

 framework covered with very fine wire-gauze, in the interior of which, connected 

 with the shaft or spindle, which is hollow, are two suction tubes, and by this means, 

 on the principle of a syphon, the dirty water constantly flows away through a larger 

 tube running down outside, which is connected with that in the centre, without carry- 

 ing away any of the fibre. 



After this, the mass is placed in another engine, where, if necessary, it is bleached 

 by an admixture of chloride of lime, which is retained in the engine until its action 

 becomes apparent. The pulp is then let down into large slate cisterns to steep, prior 

 to being reduced to a suitable consistency by the beating-engine, as already described. 

 The rolls or cylinders, however, of the beating-engine are always made to rotate 

 much faster than when employed in washing or bleaching, revolving probably from 

 120 to 150 times per minute, and thus, supposing the cylinders to contain 48 teeth 

 each, passing over eight others, as shown in the figures, effecting no fewer than 

 103,680 cuts in that short period. From this the great advantage of the modern 

 engine over the old-fashioned mortar machine, in turning out a quantity of paper-pulp, 

 will be at once apparent The introduction of colouring-matter in connection with 

 the paper-manufacture is accomplished simply by its intermixture with the pulp while 

 in process of beating in the engine. 



Although the practice of blueing paper is not, perhaps, so customary now as was 

 the case a few years back, the extent to which it is still carried may be a matter of 

 considerable astonishment. On its first introduction, when, as regards colour, the best 

 paper was anything but pleasing, so striking a novelty would no doubt be hailed as a 

 great improvement, and as such received into general use, but the superior delicacy 

 of a first-class paper now made without any colouring-matter whatever, and without 

 any superfluous marks on its surface, is so truly beautiful, both in texture and ap- 

 pearance, as to occasion some surprise that it is not more generally used. 1 



Common materials are frequently and very readily employed, through the assistance 

 of colouring-matter, which tends to conceal imperfections. Indeed, it would o 

 difficult to name an instance of apparent deception more forcible than that which is 

 accomplished by the use of ultramarine. Until recently the fine blueish tinge given 

 to many writing-papers was derived from the admixture of that formerly expen- 

 sive, but now, being prepared artificially, cheap, mineral blue ; 1 pound of ultra- 

 marine going farther than 4 of smalts, the former necessarily meets with moro 

 extended application, and where its use is rightly understood, and the materials 

 employed instead of being fine rags, comparative rubbish, excessively bleached, 

 its application proves profitable to the paper-maker in concealing for a time all 

 irregularities, and making the paper surpass in appearance the best kinds. The oxide 

 of cobalt, generally termed smalts, has still the advantage over the ultramarine of 

 imparting a colour which will endure for a much longer period. 



At first the introduction of ultramarine led to some difficulty in sizing the paper, 

 for so long as smalts continued to be used, any amount of alum might be employed, 

 and it was actually added to the size to preserve it from putrefaction. But since 

 artificial ultramarine is bleached by alum, it became of course necessary to add this 

 salt to the size in very small proportions, and, as a natural consequence, the gelatine 

 was no longer protected from the action of the air, which led to incipient de- 

 composition, and in such cases the putrefaction once commenced, proceeded even after 

 the size was dried on the paper, and gave to it a most offensive smell, which rendered 

 the paper unsaleable. This difficulty, however, has now been overcome, and providing 

 the size bo quite free from taint when applied to the paper, and quickly dried, putre- 



1 See Richard Herring's Pure Wove Writing Paper.' 



