28 GEORGE W. FULLER 



has been largely minimized, and the efficiency has been increased. 

 In the field of water and sewage purification the information and 

 experience now available are sufficient in a majority of cases to 

 enable these problems to be advantageously handled by experienced 

 workers along these lines. There are some problems, however, 

 that still can be advantageously treated by the experimental method. 

 They refer especially to sewage problems in which trade wastes 

 are involved, and to water problems where the composition of the 

 water is quite unusual in some particulars on frequent occasions. 

 From the technical standpoint, however, the field of water and 

 sewage purification, broadly speaking, has passed beyond the experi- 

 mental stage, and the advances, both as to efficiency and economy, 

 are largely to be gained, not from experimental plants, but by the 

 careful and more systematic operation of works in practice. Such 

 studies will, of course, lead to improvements which can be taken 

 advantage of in the construction of new works, and will gradually 

 bring to a higher plane of excellence the art of water and sewage 

 purification on its present scientific basis. 



Educational aspect. It is frequently said that communities 

 progress in proportion to the advance in knowledge of the average 

 citizen, or to the mean knowledge of the community as a whole. 

 There is a good deal in this, and it brings forcibly to mind the neces- 

 sity of educating the public as to what improved sanitary conditions 

 really mean, and of letting them ascertain for themselves what can 

 be accomplished along these lines in the field of applied science. 

 Non- technical people have a natural aversion to the word " experi- 

 ment," notwithstanding the aid derived from devices which not 

 improperly may be termed experimental. While the term "experi- 

 ment station" from its use at Lawrence and a few other places 

 seems to have a firm footing in some localities, it is gradually giving 

 place to the term " testing station." This is a much preferable 

 expression in many ways, as it disarms the criticism of many who 

 seem to think that these investigations are conducted in a "hit or 

 miss" manner, much after the fashion of the early inventors. This 

 is not so, as experimental methods, as now ordinarily applied to 

 water- and sewage-works, are aimed at testing procedures found 

 successful elsewhere, but which may require adaptation to local 



