EXPERIMENTAL FILTER STATIONS.
FILTRATION of the water supply bids fair to become universal wherever any suspicion is entertained as to the purity of the source. To this end experimental stations are generally made use of, and these often involve an elaborate preliminary experimentation, conducted before instituting the system of filtration that has been adopted. Those who do not understand the reason for takihg this course are apt to grumble over the delay and expense attending upon it. Anticipating these objections in the case of Philadelphia’s experiments in filtration, Dr. Abbott, director of the University laboratory of hygiene, took up the matter in a recent lecture delivered by him on the subject of “Polluted Water Supply.” He showed that, until the principles of filtration are thoroughly established, it is well known that filtration involved a considerable number of technical details, according to the character of the water that was to be treated—that is to say, a filter that will satisfactorily purify the water of one stream will not necessarily give results that would be economical and practical with the water of another stream. The water of any particular stream or body to be purified by the various processes now known to science presents its own individual problem,and before any plant for the purification of water of any such stream by the process of filtration is decided upon.it is now universally regarded as absolutely necessary and essential to determine in a preliminary way just those conditions which would give to the community the best results with the smallest outlay of money. It is to answer this question that the experimental plant now in operation at the East Park reservoir was instituted. After his lecture Dr. Abbott said that he did not believe that any competent sanitary engineer would have undertaken the problem of filtering the water of the city of Philadelphia wilhont the assistance of jnst soch experimental plants as the city has provided.