EXPERIMENTAL METHODS IN WATER- AND SEWAGE-WORKS 25 



many years been in use. But they did not secure comparable paral- 

 lel data from the engineering, chemical, and bacterial standpoints 

 with anything like the completeness obtained at Lawrence, whereby 

 the laws governing successful practice could be broadly stated for 

 a wide range of conditions. 



Not only has the Massachusetts State Board of Health availed 

 itself of a testing department, but with other departments it has 

 placed itself in a position to utilize such data advantageously. This 

 has been done by an analytical department procuring data at fre- 

 quent intervals as to the character of various water supplies, rivers, 

 effluents, etc., and, more especially, by a well-trained engineering 

 corps which applies the various data to the needs of each problem 

 coming to the attention of the board. 



That the Massachusetts State Board of Health handles well 

 the work coming within its jurisdiction is conceded by all in a posi- 

 tion to know of it intimately. It is true that the board is criticised 

 for not devoting itself more enthusiastically to studies of methods 

 finding favor elsewhere, but this criticism has little to support it. 

 The board properly confines itself to the solution of problems within 

 the state, and of course does not consider it necessary to do more 

 than keep generally familiar with other methods, no matter how 

 suitable they may be for work elsewhere. 



EXPERIMENTAL METHODS ELSEWHERE IN AMERICA. 



In water purification the Massachusetts problems are, generally 

 speaking, much easier and simpler than those of the Central West 

 and South, where enormous quantities of silt and clay complicate 

 the necessary works for treating the water, and add materially to 

 the cost as regards both construction and operation. In a manner 

 similar to the procedure at Lawrence, these problems were worked 

 out at Louisville, Pittsburg, Cincinnati, and New Orleans. At 

 numerous other places the experimental method has been used 

 in adapting more strictly the design of works to local conditions, 

 especially in the preliminary treatment of turbid waters (Phila- 

 delphia and Harrisburg), the removal of color from surface waters 

 (Providence), of iron from ground waters (West Superior), the 

 softening of hard waters (Columbus), and the removal of tastes 



