THE IRKIGATION AGE. 



75 



PLACING THE STRAINER. 



The success of the well may depend upon the 

 proper location of the strainer in the gravel stratum. 

 If the stratum consists of pure gravel the top of the 

 strainer may be placed about one foot below the top 

 of the gravel stratum, but in cases where 20 per cent 

 to 50 per cent of sand is intermixed with the gravel 

 the top of the strainer should be placed not less than 

 four feet below the top of the gravel stratum. This is 



n 



Fie, 12. A section of the wall of the 

 slotted strainer used in Station 

 well; slightly reduced in size. 



Fig. 12&. A homemade six-inch 

 slotted strainer, made and used 

 by J. S. Porcher, El Paso, Tex. 



necessary for the reason that since the slots of the 

 strainer are */ inch wide all the sand surrounding the 

 strainer will enter the well and be pumped out with 

 the water, and the gravel, which is held back by the 

 strainer, will settle to tkae the place of the sand re- 

 moved. If the top of the strainer were placed at the 

 top, or near the top, of the gravel stratum it will be 

 readily seen that when the gravel settles after the sand 

 has been removed, the top of the gravel stratum will be 

 considerably below the top of the strainer and, there- 

 fore, a portion of the strainer would be surrounded by 

 pure sand. This would mean that the sand around 

 this portion of the strainer would constantly be coming 

 into the well, and eventually enough sand would be 

 removed so that caving would finally extend to the 

 surface. 



IOWA'S GREAT DRAINAGE CONVENTION. 



Large Attendance by Prominent Landowners Professor Steven- 

 son's Report of His Investigations. 



At the opening of the Iowa drainage convention at 

 Ames President Charles F. Curtiss stated that the object 

 of this convention was to unite upon some plan of 

 action that shall result in effective good for the dis- 

 tricts; that the seasons of 1902 and 1903 show must 

 have relief from the flooded conditions to render the 

 land productive. The Department of Soils of the Iowa 

 State College, Professor Curtiss stated, has been study- 

 ing the drainage conditions of the State for several 

 months. 



Prof. W. H. Stevenson, in charge of the Soils 

 Department of the College work, made a very interest- 

 ing and significant report of his thorough investiga- 

 tion of the present drainage conditions in Iowa. .Fol- 

 lowing are some of his principal points: A letter of 

 inquiry was sent out all over Iowa. The following 

 are some of the questions it contained: How many 

 acres in your farm ? How many acres partially unpro- 

 ductive the past season on account of surplus water? 

 How many acres wholly unproductive? How many 

 rods of tile have you on your farm ? What sizes ? Have 

 you an adequate outlet? Would a drainage ditch be- 

 ef value to you and your neighborhood ? What per cent 

 of the land in your township do you think is now un- 

 productive because of a lack of drainage? 



About 1,800 replies were received from a half 

 dozen to forty from each county. Professor Stevenson 

 gave and explained a summary of the reports from a 

 few counties and districts, and the average for the State 

 as follows: 



The average size of farm reported for the whole 

 State is 249.1 acres. 



The per cent of ground partially lost for lack of 

 drainage on the farms reported, average for the State, 

 16.4. 



Per cent of land wholly lost for lack of drainage, 

 average for the State 6.7. 



Per cent of farms with no outlet, average for the 

 State, 40.1. 



Per cent of farms requiring a district drainage 

 ditch, average for the State, 25.9. 



Per cent of land in the township non-productive for 

 lack of drainage, average for the State, 12.4. 



With the above data as a basis, Professor Stevenson 

 has done some figuring in profit and loss, and here is 

 what he makes out: Number of acres non-productive 

 for lack of drainage in the whole State, 4,321,792. 

 Annual loss for lack of drainage in the whole State, 

 $21,608,960. 



The above annual loss equals 5 per cent interest 

 in the whole State, $432,479,200. Cost of proper drain- 

 age in the whole State, $108,044,800. The present 

 annual loss from lack of drainage would pay 5 per cent 

 interest on the above cost of drainage, and also pay 

 5 per cent interest on the following additional amounts 

 representing increase of wealth that would result from 

 proper drainage, in the whole State, $324,134,400. 



Annual loss to the State for lack of drainage, $21,- 

 608,960. Value of wheat in State, $12,860,000. 

 Value of the oat crop in State, $26,114,000. The loss 

 from lack of drainage is nearly double the wheat crop 

 of this State and is more than four-fifths of the oat crop. 



The annual returns from an acre are about $10.00, 

 but in order to be very safe and conservative in figuring 



