CHAPTER XVI OTHER BUILDINGS (_continued_), AND SITUATION OF BUILDINGS Sorting-room--Packing room--Store rooms--Storage of rubber-- Need for special accommodation--Floor of store room--Local conditions--Temperature and humidity--Incidence of moulds-- Effect upon smoked sheets--Tool-sheds and stores--Situation of buildings--Position with respect to points of the compass-- Choosing a factory site--Centralisation--Decentralisation 211 PART IV _THE FINISHED RUBBER_ CHAPTER XVII DEFECTS IN CREPE RUBBERS General style of finish--Dirty edges--Iron-stains--Rust-stains --Oil-marks--Trays--Dirt--Holes--Greenish and tacky streaks-- Not due to oil _per se_--Tackiness and copper--Cotton and other fibre--Bark and grit--Sand--Oxidation streaks--Yellow streaks--Bisulphite streaks--Spot disease--Cause of--Influence of rate of drying--Percentage of moisture--Humidity of atmosphere--Prevention of disease--Infection by contact-- Outbreak of dormant spores--Rules to be observed--Surface moulds or mildew--Tackiness in general--Full discussion of-- Experimental reproduction--Lack of uniformity in colour-- Defects in block rubber 223 CHAPTER XVIII DEFECTS IN SHEET RUBBER Defective coagulation--Coloured surface blotches--General darkening of surface--Soft coagulum--Spongy underface--Tearing --"Pitting" of surface--Thick ends or edges--Mis-shapen sheets --Thick patches--Torn sheets--"Dog-ears"--Creases--Greasiness of surface before smoking--Surface blemishes--Uneven appearance--Variation due to oxidation--Colour when dry-- Surface gloss--Dull surface--Moist glaze and greasiness-- Virgin spots--Surface moulds or mildew--Black streaks or spots --White or grey streaks--Rust--Theories on formation of-- Prevention of--Two methods--Other views on causation--Bubbles --Causes of formation--In the field--In the factory--Blisters --"Spot" disease in sheet rubber--Support marks--Stickiness-- Surface pattern--Sheet clippings--Other infrequent defects-- Dirt--Ash--Bark--Splinters 249 PART V _GENERAL_ CHAPTER XIX CHOICE OF COAGULANT Acetic acid in general use--Is a coagulant necessary?--Acetic acid--Formic acid--Citric acid--Tartaric acid--Oxalic acid-- Sulphuric acid--Hydrochloric and nitric acids--Hydrofluoric acid--Alum--Pyroligneous acid--Smoked water--Chinese vinegar-- Sulphurous acid--Sugars--Various salts--Proprietary compounds --Carbonic acid gas--Alcohol--Vegetable extracts 278 CHAPTER XX SPECIAL METHODS OF PREPARATION