Prior thereto the inhabitants in that part of India obtained their supply from polluted ponds and other unwholesome sources. The Irrigation works of India are extensive and have done something to relieve the deplorable conditions of the millions untutored in hygienic science. All such Indian watercourses as the extensive Punjab Triple Canal system, the Bengal system, the Madras canals, the Ganges and the Indus systems supplied waters for ir rigation and formerly to some extent waters for navigation. In a land of such intense heat and extensive barren areas, most of such water courses supplied all the water obtainable for potable as well as for all other purposes. Slowly the people of the peninsula are begin ning to understand some of the causes of the cholera, typhoid and other fatal epidemics that have swept over India from the Buddhist period, commencing 520 tic. down to recent years. Who can estimate India's mortality directly attributable to its pathogenic-bacteria polluted water supplies? What costly sacri fices the race has made to its ignorance of and failure to observe the laws of health! Polluted waters are disease producers, as unfailing as the forces of gravity on falling bodies. India with its dense population and appalling pesti lential epidemics is an inimitable example of the dreadful results of the use of unwhole some waters for domestic and potable pur poses. Modern modification processes have been installed in its principal cities and ports. so the danper of infection in those towns is constantly less g. In 1914 Bombay consumed V gallons, and Calcutta 62 gallons daily per capita. In the waterworks of Calcutta alumino-ferric is used as a purifier, which is an impure sulphate of aluminum. That is gen erally used as a coagulant elsewhere in India. Mechanical filters at Betrnangub, India, re duced the bacteria in Palau River water from 4.350 to 13 per cubic centimeter. The train ing of souse of the river courses, such as the Rangoon. has resulted in the improvement of their waters for domestic uses. 1.radnally the people arc beginning to realize the importance of preserving their streams and watercourses, including reservoirs, tanks, etc., from pollution.
China and Japan in the past centuries were hardly less oblivious of hygienic and sanitary laws, though less frequently swept by epidemics attributable to waterborne diseases. The Chinese obtain their water supplies from wells, springs and their rivers. There appears to be some natural purification of their waters and less human pollution of them. They are ac customed to boil their drinking water and that disposes of many bacteria.
Japan is abundantly supplied with lakes, rivers and waterfalls and is fast advancing in sanitary science. It has already commenced to adopt some western methods for the purifica tion of its water supplies. George A. Johnson of the United State Geological Survey says: That lithe water purification works at Osaka, Japan, having a daily capacity of gallons, include open sedimentation basins and also sand filters.' One was completed in 1903. Bacteria in Yodo River water were reduced from 200 to 25 per cubic centimeter. There is also a slow sand filtration plant at Yokohama, whose water supply is taken from the Sagami gawa. Water purification is also effected to some extent in Tokio, where were consumed in 1914, daily 32 gallons by each of its 1,500,000 residents. It takes its water from the river
Tama into the city reservoir at Yodobashi, located high enough to afford nearly 100 feet pressure. There potash alum was used as a purifier. At Kyoto there is a large rapid sand filtration plant.
Melbourne in Australia derives its water supply from the Yan Yean system, consisting of Silver Creek, Wallaby Creek and the Plenty watershed yielding 33,000,000 gallons daily and from the Maroondah or Watts River system yielding 25,000,000 gallons daily, and from Survey Hills yielding 9,000,000 gallons daily. There are six service reservoirs with a combined capacity of 45,000,000 gallons. The daily supply in 1905 was 63 gallons per capita. In 1899 the waters in the service reservoirs and mains carried from 146 to 398 bacteria per cubic centimeter. B. toll were found in some reservoirs fed from drainage areas, where there was no sewage and other micro-organisms were also found. That shows how prevalent they may be when least expected. The presence of such bacteria is usually attributable to pol lution by sewage. The obtaining of pure and wholesome water is not the least of municipal problems nor of rural communities.
In New South Wales a dozen or more nar now gorges have been dammed and their waters impounded for domestic purposes. So in all inhakted parts of the world, the problem water supply is of first importance, and is be coming increasingly so as the population in creases in density.
Some American City Supplies.— In ad dition to the municipal supplies already men tioned, the illustrate the methods adopted in the United States for obtaining wholesome water supplies.
Boston, Macs, is in the Metropolitan kV:ore District, which obtains its fr, in lakes and rivers, whose waters in reservoirs. Cochituate Lake. Sudbury River and the south branch of the Nashua River are its principal sources. The first of these com prises a series of ponds three and one-half miles long, and their waters flow through an aque duct into Chestnut Hill reservoir, having a capacity of 23,000,000 gallons a day. On the Sudbury River four storage reservoirs, an aqueduct and a conduit were built. They carry 108,000,000 gallons a day, 15.9 miles to the Chestnut Hill reservoir. The waters of the south branch of the Nashua are impounded in the large ‘Vachusett reservoir, at Clinton, hav ing a capacity of 64,500,000,000 gallons in its 6.46 square miles of area. It is 12 miles from the Sudbury reservoir, into which its waters are conducted by the Wachusett aqueduct, and from one of the Sudbury reservoirs by the Western aqueduct built in 1904, to the westerly part of the metropolitan district. The 1V of the Wachusett aqueduct is 300 gallons. The site and shores of the Wachusett reservoir were stripped and that proved satis factory, for alga and other plant organisms do not thrive where rock constitutes the bottom and sides of such reservoirs. The water in the reservoirs is not polluted and is remarkably free of organisms, due to the stripping of the sites and the freedom of the catchment areas from pollution, except such as are within the towns of Marlborough and South Borough. Diatonsacca have been found in Lake Cochit uate and occasionally small numbers of harm less bacteria in the tap water.