At Ashton, England, ozonization is reported to disinfect and to reduce color, tastes^ and odors; similar reports have come from Germany but costs of operation were found to be higher than with chlorine. Ozonization was discontinued at the Belmont filters in Philadelphia in 1959 due to the degradation of raw water improvements water improvements under way will provide large basins for the Cg detention time needed for free residual Chlorination before other chemical treatment. See M0ao addition of fluorides to the water delivered into the distribution system has been a moot political and religious problem sfnce 1945 when fluorides were first introduced nto public water supplies. In 1958, the World
Where current revenues do not provide sufficient funds for urgently needed road improvements, borrowing is justified. It is generally held that highway debt should be repaid within the life of the improvements made. Highway surfaces wear out and must be replaced, but grading has permanent value and drainage structures last for a long time. When a surface is worn out, it still has value as a base for a new surface. One third or more of the cost of a new highway may be for improvements that will be of value for many years after the original surface is replaced.
Improvements in the beneficiation of ceramic w materials are probably no less important than ie development of new ceramic materials. For :ample, kaolins that have been subjected to caching and particle size selection are being used stead of the more expensive titanium dioxide in e coating of fine paper; and improved particle lection of flint has made possible the develop-ent of higher strength porcelains. There have :en improvements in the selection and grinding
nepheline syenite for fluxing glasses and ceramies. Potting clays have been improved by particle selection and purification.
At Ashton, England, ozonization is reported to disinfect and to reduce color, tastes^ and odors; similar reports have come from Germany but costs of operation were found to be higher than with chlorine. Ozonization was discontinued at the Belmont filters in Philadelphia in 1959 due to the degradation of raw water improvements water improvements under way will provide large basins for the Cg detention time needed for free residual Chlorination before other chemical treatment. See M0ao addition of fluorides to the water delivered into the distribution system has been a moot political and religious problem sfnce 1945 when fluorides were first introduced nto public water supplies. In 1958, the World