experiment has been of incalculable benefit to sanitary science, and the results have been not only of local and immediate value, but they have acquired a world-wide reputation and form a permanent contribution to scientific literature. If one doubts the practical worth of a laboratory in the management of a water-works system, no more convincing argument could be presented than the fact that a private water company in Wilkesbarre, Pa., has recently gone to the expense of establishing a laboratory for chemical, microscopical and bacteriological analyses of the Water sold to the community, and this in spite of the fact that the water supply is taken from a watershed not seriously open to the danger of contamination. The work is in charge of Prof. Wm. H. Dean.
It is an interesting fact that in many instances the laboratories have been found to have a wider field of usefulness than that for which they were originally intended. For example, the laboratory in Cincinnati did not cease its existence when the filtration experiments were completed; it was continued as a laboratory for testing the materials of engineering construction. It is now in charge of Mr. J. W. Ellms, Chemist, under the direction of Mr. Gustav Bouscaren, Chief Engineer. The building has seven rooms and contains not only the apparatus necessary for water analysis and general chemical work, but a complete outfit for testing cement. The work now includes the chemical analysis of paints and oils, asphalts, rock, sand and cement, physical tests of cement, besides experimental investigations of the properties of cement mortars and asphalts.
At Pittsburg, also, the laboratory has been made permanent. The Department of Public Works has erected a two-story brick building, known as the Herron Hill Laboratory. The first floor and basement are used by the Bureau of Water Supply for water analysis, tests of supplies purchased and experimental work upon the filtration of water; the second floor is used by the Bureau of Engineering as a cement laboratory. In the water laboratory the floor and operating-shelves are covered with white tiles and the walls are painted with white enamel, so that the room may be washed from ceiling to floor. Steam from a neighboring boiler house is used for heating the water-baths and for distilling water. The incubators used for bacteriological work are placed in the basement, where the temperature can be kept more constant than on the floors above. The ammonia stills, sterilizers, autoclav and other apparatus are of the most modern type. A safe in the basement serves to protect the records in case of fire. One biologist, one chemist and one attendant are employed in the water laboratory, and a chemist is employed in the department of cement testing. Mr. Wm. R. Copeland is the biologist in charge.
In the Mt. Prospect Laboratory, of Brooklyn, the miscellaneous work is constantly increasing. The coal used at the various pumping stations
