SIXTH ANNUAL YEAR BOOK — PART I. 31 



age to an extent which has not been understood until recently, yet it is 

 also true that after the fall of Rome the principles of sewerage were lost 

 sight of for hundreds of years. In fact the development of sewerage 

 according to modern principles is mainly the work of the last one hun- 

 dred, years. Prior to that time work in this line was not done according 

 to scientific principles, but in general followed no systematic plan, drains 

 hardly worth the name of sewers being constructed here and there as 

 necessity compelled. The development of sewage disposal has been or 

 still more recent date. Until within the last twenty-five years the one 

 thing done with sewage was to carry it to the nearest possible outlet, 

 and there empty it without regard to the health or convenience of other 

 communities. 



"Within the last twenty-five years, however, the necessity for disposing 

 of sewage by more scientific means has been forced upon an unwilling 

 public, and a great amount of attention has been given to the subject. 

 Some of the most important developments have occurred within the last 

 ten years and the work of research and improvement is still going on. 



In Iowa the first sewage disposal plant was built in 1898, only seven 

 years ago, but since that time quite a number of plants have been put 

 in operation and during the present year alone five sewage purification 

 plants have been under construction. What is being acomplished in Iowa 

 along this line may be judged from an inspection of the two bottles 

 which I have here, one of which contains sewage effluent from the first 

 sewage disposal plant built in Iowa, viz., at the Iowa State College, Ames, 

 Iowa, while the other contains pure well water from the water supply 

 of the same college. In case any of this audience are further interested 

 in what is being done by Iowa towns in the way of sewage disposal, I 

 have here for distribution copies of Bulletin No. 7 of the Engineering 

 Experiment Station of the Iowa College which describes all the 

 plants built in the state prior to 1904. Annually the Engineering Experi- 

 ment Station inspects all the plants in the state, making chemical and bac- 

 terial tests of the efficiency and obtaining data of the working of the 

 plants. 



Within the last two or three years an increasing number of inquiries 

 have been coming to the Engineering Experiment Station as to what 

 can be done with sewage on the farm, and to enable us to obtain, if 

 possible, the proper answer for these queries, we have been experimenting 

 with sewage disposal plants for private houses, such as can be built for 

 a small sum of money, within the reach of the ordinary well-to-do 

 farmer. It is slow work carrying out such experiments properly, since 

 any particular method of disposing of sewage should be tested for at least 

 one entire season before it can be certain that it is a success, and as a 

 result we have not been willing to publish the results of our work, nor 



