CHARLES GRIFFIN & COMPANY'S STANDARD TECHNOLOGICAL HANDBOOKS. OILS, FATS, WAXES, and Allied Materials, and the Manufacture therefrom of CANDLES, SOAPS, and OTHER PRODUCTS. By. C. R. ALDER WRIGHT, D.Sc., F.R.S., Lecturer on Chemistry, St. Mary's Hospital School; Examiner in " Soap" to the City and Guilds of London Institute. With numerous Illustrations. DYEING (A Manual of). For the Use of Practical Dyers, Manufacturers, and Students. By Dr. KNECHT, of the Manchester Technical School, CHR. RAWSON, F.C.S., of Bradford, and Dr. R. LOEWENTHAL. In Large Svo, with numerous Illustrations. STEAM AND STEAM ENGINES (A Text-Book on). By A. JAMIESON, M. Inst.C. E., F.R.S. E., &c., Professor of Engineering, Glasgow and West of Scotland Technical College. With over 200 Illustrations, Six Folding Plates, and Examination Papers. SEVENTH EDITION, Ss. 6d. "The BEST BOOK yet published for the use of students."-Engineer. STEAM BOILERS: their Defects, Management, and Construction. By R. D. MUNRO, Engineer of the Scottish Boiler Insurance Company. Very fully illustrated. SECOND EDITION, Enlarged. 4s. 6d. "Trustworthy, clear, and practical."- Engineer. "A valuable companion for workmen and engineers engaged about Steam Boilers,. ought to be carefully studied, and ALWAYS AT HAND."-Colliery Guardian. PHOTOGRAPHY (A Text-Book of): its History, Processes, Apparatus, and Materials. Comprising Working Details of all the more important Methods. By A. BROTHERS, F.R.A.S. With 24 Plates illustrating many of the Processes described. 18s. "Certainly the FINEST ILLUSTRATED HANDBOOK to the subject which has ever been published."-Amateur Photographer. the PRACTICAL HINTS of GREAT VALUE.”—Brit. "A most comprehensive volume. Journ. of Photography. LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND. COLOURS, OILS, AND VARNISHES: A PRACTICAL MANUAL. BY GEORGE H. HURST, F.C.S., MEMBER OF THE SOCIETY OF CHEMICAL INDUSTRY; LECTURER ON THE TECHNOLOGY OF PAINTERS' COLOURS, OILS, AND VARNISHES, CHARLES GRIFFIN & COMPANY, LIMITED, EXETER STREET, STRAND. 1892. [All Rights Reserved]. PREFACE. IN offering the following pages to Practical Workers and others interested in the wide subject of "Painters' Colours, Oils, and Varnishes," my aim throughout has been to combine theory and practice, and to show the scientific principles that underlie the methods in constant use. Naturally-and one may say unavoidably-there has grown up in the course of years, in connection with Colour-making, as with every other industry, a good deal of what is known as "Rule of thumb" procedure. The amount of this that prevails, however, has been greatly overrated, and we are not far distant from the day when "Rule of thumb" will be generally supplemented among us by an intelligent appreciation of the scientific principles involved. To give the rationale of every technical process is, nevertheless, by no means an easy task, and all that I can hope to have effected is the placing before the reader such a description of the various processes and their underlying principles, as shall be really helpful in practical work. The information given as to the properties and preparation of Pigments, is either based on. my own experience, or drawn from the most trustworthy sources. For a revision of the chapter on Varnishes, and many excellent suggestions, I am indebted to a personal friend, practically engaged in their b |