Overview: stone cleaning, for better or worse? - an overview, Ingval Maxwell. Part 1 The broad issues: a brief history of grime - accumulation and removal of soot deposits on buildings since the 17th century, Peter Brimblecombe; towards an aesthetic theory of building soiling, Chris Andrew; stone cleaning - a professional view, James Simpson; sources of building soiling and a review of the stone cleaning industry 1991, Trudie Mansfield. Part 2 Case studies and experimental investigation: to clean or not to clean buildings within Edinburgh, Alastair Milligan; Scott Monument - a brief study report, Hurd Rolland Partnership, John Dixon; the cleaning of the Palace of Westminster, Chris Tucker; a conservator's approach to architectural stonework, Jane Porter; the composition and weathering of sandstone with relation to cleaning, Brian Bluck; abrasive cleaning of sandstone buildings and monuments and experimental investigation, Maureen Young and Dennis Urquhart; research on cleaning methods applied to historical stone monuments, Martin Werner and Claudia Neuwald; experience with cleaning and consolidating stone facades in Hungary, Mihaly Zador. Part 3 The cleaning of carbonate stone: stone cleaning by the inversion of gypsum back into calcium carbonate, Theodor Skoulikidis and Paraskevi Papakonstantinou; removal of sulphated-crust from marble using sulphate reducing bacteria, K. lal Gauri et al; geochemical considerations in the cleaning of carbonate stone, Richard Livingstone. Part 4 Urban conservation issues: acid rain - the cleaning and conservation of stonework in Bath, David McLaughlin; conservation and planning considerations in stone cleaning, Chris Andrew and Emma Crawford; stone cleaning in urban conservation, Dennis Rodwell; building cleaning - process or procedure, an industry view, Craig Liddle. Part 5 Chemical and microbiological studies: chemical cleaning of sandstone - comparative laboratory studies, John MacDonald et al; effects of particulate air pollutants on materials - investigation of surface crust formation, Brian Whalley et al; the impact of stone cleaning on micro-organisms and microbially influenced corrosion, Markus Wilimzig et al; microbial interactions with building stones, with special reference to various cleaning, conservation and restoration techniques, Wolfgang Krunbein et al; microbiological damage to building stone - analysis and intervention, Robert Palmer Jr. Part 6 Stone decay, weathering and future prospects.