My thanks are due to many who have been good enough to assist me in this work, and especially to Lieutenant-Colonel Whitwell and Captain J. C. Vaughan of the Indian Medical Service; to Mr. A. E. Silk, Sanitary Engineer to the Government of Bengal; and to Captain D. Meagher, the Officer in charge of the Government Farm at Allahabad. G. W. D. _November 1901._ PREFACE TO SECOND EDITION. The First Edition of this work was favourably received and, being entirely disposed of within five months of its issue, indicates that a want was met. The Manual has been patronised by the Government of India, the Secretary of State for the Colonies, the Local Governments of Bengal, Madras, Burma, Punjab, the United Provinces of Agra and Oude, Assam, the Central Provinces, the North-West Frontier Provinces, Baluchistan, and other Administrations, as well as by several Native States, and by the Nepal Durbar. A Second Edition with a good deal of additional matter added, has therefore been prepared, but this has been called for before the Author was ready for it, and estimated results have in consequence been given in several instances instead of recorded facts. The science of sanitation is, however, progressing so rapidly, that a good deal of useful information is available, and advantage has been taken of criticisms to amplify several points. Additional information has been given on the Biological System of Disposal of Sewage, on Markets, and Drain Flushing among other subjects, and Appendices C to F have been added. I take this opportunity of again thanking many who have assisted me, and for the generous tone of the criticisms in the public press. MUZAFFARPUR, │ G. W. DISNEY. _15th November 1902_. │ CONTENTS.