EXPERIMENTAL METHODS IN WATER- AND SEWAGE- WORKS 21 



teaching staff have achieved results which will be more fully appre- 

 ciated as the years go by. 



While the experimental method so successfully applied in the 

 student laboratory may in its way call for just as conscientious and 

 diligent effort as when applied to projects involving immense sums 

 of money, yet the responsibility associated with the latter is far 

 greater. It is necessary, in carrying out successfully these large 

 practical problems, not only to draw correct conclusions from full 

 representative premises of a complicated nature, but also to adjust 

 the project to a reasonable business basis, to make it fairly well 

 understood by non-technical officials and citizens, and to defend 

 it from the obstructionists who, for political or selfish reasons, cross 

 the pathway of nearly every large public enterprise. In meeting 

 these requirements there has been called forth a series of efforts 

 which are of great significance to the public from the sanitary and 

 financial standpoints, and which form notable achievements in the 

 field of applied science. 



BENEFITS OF IMPROVED SANITARY WORKS. 



Improved water- and sewage-works of course do not explain 

 by any means the entire improvement which for the past quarter 

 of a century has been so characteristic of the sanitary conditions 

 of a majority of the civilized communities of the world. But, illus- 

 trative of the scope of such improvements under the guidance of 

 wise sanitary authorities, it is of interest to point out the markedly 

 decreased death-rates in Massachusetts from water-borne diseases, 

 of which typhoid fever is the typical, but not the only one. 



DEATH RATES PER 100,000 POPULATION FROM TYPHOID FEVER IN THE STATE OF MASSACHUSETTS 

 BY FIVE-YEAR PERIODS FROM 1881 TO DATE. 



What is true of Massachusetts is in a general way true of many 

 sections of both America and Europe where the population has 

 become quite dense, and demands for water- and sewage-works of 

 satisfactory character have pressed forward for attention in recent 



