Coal-tar colours -- Acid and basic colours -- Theories of dyeing -- Fixation of colours on leather -- Mordants and mordant colours -- Curriers’ inks -- Glazes and finishes -- “Assistants” in dyeing -- Bronzing -- Fading of colours -- Practical methods of leather dyeing -- Use of dyewoods -- Iron “strikers” -- Tannin blacks -- Staining -- Theory of colour-mixtures -- Finishing dyed leathers -- Testing of dyes -- Injurious effects of metals in dyeing PAGE 394 CHAPTER XXVI. _EVAPORATION, HEATING AND DRYING._ Theory of evaporation -- Boiling point and vapour-pressure -- Consumption of heat in evaporation -- Heat-units -- Mechanical energy of heat -- Evaporation by “multiple effect” -- Vapour-pressure of atmospheric moisture -- Wet and dry bulb thermometers -- Heat and air required in leather-drying -- Loss of heat by buildings -- Quantity of heat given by steam and hot-water pipes -- Screw-fans for drying -- Centrifugal fans -- “Turret” dryer -- Downward ventilation -- Arrangement of steam-pipes -- Hot water pipes PAGE 420 CHAPTER XXVII. _CONSTRUCTION AND MAINTENANCE OF TANNERIES._ Selection of site -- Arrangement of buildings -- Fire insurance -- Automatic sprinklers -- Possibility of extension -- Production and distribution of power -- Electric motors -- Shafts, pulleys and belting -- Balancing of machinery -- Fire-risk from bark mills -- Chain-conveyors -- Lubricating oils -- Construction of pits -- Underground pipes and overhead troughs -- Pumps and pumping appliances PAGE 444 CHAPTER XXVIII. _WASTE PRODUCTS AND THEIR DISPOSAL._ Hair -- Fleshings and glue-stuff -- Fat -- Bate-shavings -- Horns -- Spent tan -- Tan-furnaces -- Sewage and other waste liquids -- Chemical purification of sewage -- Settling tanks -- Filter-presses -- Bacterial purification of sewage -- Tannery waste-liquors PAGE 460 APPENDIX A. _METHOD OF THE INTERNATIONAL ASSOCIATION OF LEATHER-TRADES CHEMISTS FOR THE ANALYSIS OF TANNING MATERIALS: Corrected to 1901._ Sampling from bulk -- Preparation for analysis -- Preparation of infusion -- Determination of tanning matters and non-tannins -- Colour-measurement -- Analysis of used liquors PAGE 475 APPENDIX B. _THE DECIMAL SYSTEM._ Metrical weights and measures -- Centigrade thermometer PAGE 481 APPENDIX C. _METHOD OF ANALYSIS OF TANNING MATERIALS OF THE AMERICAN ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS: Corrected to 1901._ Preparation of sample -- Quantity of material -- Moisture -- Total solids -- Soluble solids -- Non-tannins -- Tannins -- Testing of hide-powder -- Testing non-tannin filtrate PAGE 482 APPENDIX D. _LISTS OF COAL-TAR DYES SUITABLE FOR DYEING AND STAINING LEATHER, furnished by Mr. M. C. LAMB._