June 17, 1920] 



-^N/lTLtR^ 



481 



Mr. Chalmers has cjone. good service in showing-, 

 that the processes involved are so. many as to 

 justify .the issue of a book giving detailed descrip- 

 tions of the special machinery. 



After a brief introductory chapter dealing with 

 .sundry historical facts the author proceeds to 

 classify the machinery and apparatus under the 

 several processes of manufacture, beginning with 

 rag-choppers and dusters, as required for cleaning 

 material preparatory to chemical treatment. The 

 well-known types of cutters and dusters are 

 clearly illustrated. 



The section devoted to the boiling of fibrous 

 material is incomplete owing to the omission of 

 multiple-effect evaporators, the rotary incinerator 

 furnace, causticising pans, and the plant necessary 

 for the recovery and causticising of spent liquors. 

 This is to be regretted. 



The processes for washing, breaking, and 

 bleaching the boiled materials are next described, 

 being accompanied by drawings of machinery in 

 common use. Masson and Scott's bleaching- 

 tower system is shown as dependent for its effici- 

 ency on the continual circulation of bleached 

 stock. Experience has proved that intermittent 

 circulation gives good results with economy in 

 power. Plant used for pulping is well represented 

 by the Kollergang and various kneading 

 machines. 



The important and difficult subject of beating is 

 fairly handled, the temptation to describe "freak " 

 beating engines being avoided. The merits of 

 beaters with separate circulating devices are dis- 

 cussed, and the special functions of refiners clearly 

 described. The value of this section of the book 

 would have been greatly enhanced by the inclu- 

 sion of precise details as to power consumption, 

 capacity, output, and costs of maintenance. The 

 author appears to have confined his attention to 

 the description and illustrations of the machinery. 



Chaps, vii. to xi. are devoted to the production 

 of an endless sheet of paper, and give an ex- 

 cellent account of the Fourdrinier machine used 

 for this purpose. The illustrations are mainly 

 produced from the machine in operation at the 

 Daily Telegraph paper-mills, Dartford. 



The wear-and-tear of the machine wire is amply 

 shown by the statement that the load on a loo-in. 

 machine wire may be i^ tons, due to the vacuum 

 at the suction-boxes. No reference is made to the 

 much-advertised suction-roll which came into 

 prominence some years ago. 



The importance pf^. ^ stuff-catcher, or econtx- 

 miser, for saving. the fine fibres and loading in the 

 backwater is referred to, and Fiillner's s^ve-all 

 stands as the typical machiqe for the purpose.. 

 This appliance is now almost entirely superseded 

 NO. 2642, VOL. 105] 



by the ' vat-mould type of save-all with large, 

 hollow cjflinder and eh(?les"s felt.'- -^-' 



The many designs of pulp-strainers are fully 

 illustrated, from the original flat .type of early 

 days to the circular, oscillating forms of modern 

 times. The finishing processes of paper-making 

 are illustrated by tub-sizing machines, calenders, 

 and cutters. 



Chap. xiv. is devoted to a description of wood- 

 pulp and its manufacture, necessarily brief be- 

 cause very little wood-pulp is made in this country. 

 Only one or two mills are seriously occupied with 

 its manufacture. 



The two most interesting chapters in the book 

 are those dealing with "The Coating of Art 

 Paper " and " The Coating of Photographic 

 Paper." The author is probably correct, so far 

 as our memory serves us, in saying that the in- 

 formation given in this connection is in many 

 respects quite new, and much fuller than any 

 previously published. 



A full description of a plant for coating art 

 paper, manufactured by Messrs. Mather atid Piatt, 

 Ltd., is illustrated with excellent drawings and 

 diagrams. It is, of course, well known to 

 our readers that the paper when coated is formed 

 up into long loops, or festoons, which are carried 

 along on endless chains, being gradually 

 dried by warm air. A long room is used for 

 the purpose. In some cases the trackway has 

 to be made longer by bending, so that the festoons 

 can be carried to and fro in a short room. This 

 is effected by the use of "bends " in the trackway, 

 and a complete lay-out of an installation of this 

 kind made by Messrs. Masson, Scott, and Co. is 

 given in the text. 



We should not be surprised if many readers 

 interested in paper-making were to obtain a copy 

 of this book on account of the last sections, 

 devoted to the coating of photographic paper. The 

 author rightly emphasises the absolute importance 

 of the body paper, its cleanliness and freedom 

 from iron and metallic particles. The use of 

 baryta, or barium sulphate, is described, and also 

 the special machinery for imparting the sensitised 

 emulsion. 



Taking the book as a whole, we are glad to 

 recommend it to those associated with the paper 

 industry. The average engineer of experience 

 may not find much with which he is not already 

 familiar, but to a large class of readers a. book 

 of this type must be welcome. • It is copiously 

 illustrated by drawings and diagrams, most of 

 which have been supplied or lent by two Scottish 

 engineering, firms who understand the value of 

 being obliging and courteous. 



R. W, SlNDALL. 



