FOURTH ANNUAL YEAR BOOK — PART VI. 447 



Factor, with blank spaces for filling in particular names and adding 

 -special riauses as individual pieces of work may demand, and he ought 

 io furnish a copy of such printed forms with each set of plans he pre- 

 l)ares. At present there is too often only a general verbal agreement 

 l)etween the land owner and the ditcher. There is no way to enforce 

 -;ood work in all particulars, and too often disputes and dissatisfaction 

 regarding the agreement and the work arise v/hich could readily have 

 been prevented had there been written specifications and agreement. 

 The specifications and form of agreement given on pages 121 to 125 of 

 that valuable little book by C. G. Elliott, entitled "Egineering for Land 

 Drainage," may be recommended as furnishing valuable suggestions 

 along this line. 



Another very important part of engineering for tile drains which is 

 now too much neglected is close supervision by the engineer of the entire 

 work of construction. The best plans and specifications will be of little 

 avail if not faithfully carried out in actual construction. The land 

 owner is not entirely by himself, able properly to supervise the work. 

 for he is not posted as to the points requiring ctose watcii. The engineer 

 should set grade stakes for the entire work, and he should visit the work 

 one or more times during construction to see that it is properly done 

 in every way. With his level, after the tiles are laid, he should test 

 The tile at frequent intervals before the ditch is filled to see that the 

 work conforms to the grade stakes. In case unforeseen diflEiculties. such 

 as strata of quicksand, are encountered, the engineer should be informed, 

 and should test the work with especial care in such places. The en- 

 gineer should see that satisfactory protection is provided at all outlets, 

 and that good, smooth and tight junctions and easy curves are con- 

 r^tructed. 



As a final word of advice in regard to tile drains I v/ould say. make 

 them of ample size and put them down to a good depth, not less than 

 four feet if possible, and certainly not less than three feet even in The 

 very lowest ground. In, case the drain must take surface water as well 

 as under drainage, half the size can be saved by constructing over !'. 

 to remove the excess of surface water in heavy storms, a broad, shallov.- 

 depression, which can be cultivated or kept in grass. _ 



We come next to the subject of drainage ditches. These should bo 

 constructed only for quite large tracts of land, for ditches are a nuisance 

 to cultivation and often do much damage by wash where there is a good 

 fall, so that for all small tracts it is very much preferable to construct 

 tile drains. Hence drainage ditches are usually constructed not by indi- 

 vidual land owners, but by drainage districts, and this fact considerably 

 affects the engineering side of the work. The two wet seasons of 1902 

 and 1903, occurring just at a time when Iowa land had become very 

 valuable, have directed a great deal of attention to the construction 

 of drainage ditches in Iowa. In some counties the projects are to be 

 numbered by the dozen, and it has been impossible during the past year 

 to find drainage engineers enough to make the surveys required by law. 

 In some cases the ditches are of great magnitude and length. The sub- 

 ject is certainly one of great importance. 



