And there is no group of municipal problems which demands and is now commanding, more scientific thought and more intelligent business management than the collection and disposal of a city’s wastes. With every nation applying the last ounce of economy and with the increase of population and its consequent congestion, these problems grow in importance and complexity. Higher living standards, a better understanding of the causes of disease, and a keener appreciation of preventive work have forced municipalities to frown upon primitive methods involving individual effort, especially where congestion exists. As a substitute therefore, more effective means have been and are being adopted to eliminate by community activity, the nuisances caused by ashes, rubbish, garbage and dirty streets. We are also appreciating the need for more efficient management than is now prevalent and for the development of revenue-producing by-products. An official or layman interested in the solution of these six important municipal housecleaning problems will find in this book information which we believe will answer all his questions. Our judgment has been influenced entirely by the hundreds of questions which have come to the State Bureau of Municipal Information from city officials in their effort either to establish efficient systems or to reorganize existing ones. City officials, federal, state and municipal reports, engineering, medical and other publications, as well as the proceedings of various municipal, civic and scientific organizations have contributed their quota to this work. THE AUTHORS. BIBLIOGRAPHY _STREET CLEANING_: Milwaukee, Wis. Bureau of Municipal Research. Efficiency and Economy in Municipal Work by Modern Type of Equipment. Philadelphia. Highways and Street Cleaning, Bureau of Highways—A Problem in Municipal Housekeeping. Fox, R. T. Report on Examination of Personnel, Methods of Work and Equipment of the Department of Street Cleaning, New York City. Parlin, R. W. Flushing—Its Place in the Street Cleaning Field. _SEWAGE DISPOSAL_: Daniels, F. E. Operation of Sewage Disposal Plants. Kershaw, G. B. de B. Guide to the Reports, Evidence, and Appendices of the Royal Commission on Sewage Disposal. Kershaw, G. B. de B. Sewage Purification and Disposal. Metcalf, L., and Eddy, H. P. American Sewerage Practice. Disposal of Sewage. Eddy, H. P. Extent to which Sewage can be Purified by Practical Methods of Artificial Treatment now in Use. Faber, D. C. Operation and Care of Sewage Disposal Plants. Fuller, W. B. Sewage Disposal by the Activated Sludge Process. Bristol, L. D. Municipal Sewage and its Care. American Public Health Association. Standard Methods for the Examination of Water and Sewage.