General View of Filters at Hamburg.
[Frontispiece.]
THE FILTRATION
OF
PUBLIC WATER-SUPPLIES.
BY
ALLEN HAZEN,
MEMBER OF THE AMERICAN SOCIETY OF CIVIL ENGINEERS, THE BOSTON SOCIETY OF CIVILENGINEERS, THE AMERICAN WATER-WORKS ASSOCIATION, THE NEW ENGLANDWATER-WORKS ASSOCIATION, THE AMERICAN CHEMICAL SOCIETY,THE AMERICAN PUBLIC HEALTH ASSOCIATION, ETC.
THIRD EDITION, REVISED AND ENLARGED.
SECOND THOUSAND.
NEW YORK:
JOHN WILEY & SONS.
London: CHAPMAN & HALL, Limited.
1905.
Copyright, 1900,
BY
ALLEN HAZEN.
ROBERT DRUMMOND, ELECTROTYPER AND PRINTER, NEW YORK.
[Pg iii]
PREFACE TO FIRST EDITION.
The subject of water-filtration is commencing to receive a great dealof attention in the United States. The more densely populated Europeancountries were forced to adopt filtration many years ago, to preventthe evils arising from the unavoidable contaminations of the riversand lakes which were the only available sources for their publicwater-supplies; and it has been found to answer its purpose so wellthat at the present time cities in Europe nearly if not quite equal inpopulation to all the cities of the United States are supplied withfiltered water.
Many years ago, when the whole subject of water-supply was stillcomparatively new in this country, filtration was considered as a meansfor rendering the waters of our rivers suitable for the purpose ofdomestic water-supply. St. Louis investigated this subject in 1866,and the engineer of the St. Louis Water Board, the late Mr. J. P.Kirkwood, made an investigation and report upon European methods offiltration which was published in 1869, and was such a model of fulland accurate statement combined with clearly-drawn conclusions that, upto the present time, it has remained the only treatise upon the subjectin English, notwithstanding the great advances which have been made,particularly in the last ten years, with the aid of knowledge of thebacteria and the germs of certain diseases in water.
Unfortunately the interest in the subject was not maintained inAmerica, but was allowed to lag for many years; it was cheaper to usethe water in its raw state than it was to purify it; the people becameindifferent to the danger of such use, and[Pg iv]the disastrous epidemicsof cholera and typhoid fever, as well as of minor diseases, which sooften resulted from the use of polluted water, were attributed to othercauses. With increasing study and diffusion of knowledge the relationsof water and disease are becoming better known, and the present stateof things will not be allowed to continue; indeed at present there isinquiry at every hand as to the methods of improving waters.
The one unfortunate feature is the question of cost. Not that the costof filtration is excessive or beyond the means of Americ