The farmers of Illinois have, in many sections, been avoiding the main question in the drainage of our rich prairies, and that is the improvement of the natural water courses so that they will carry off the drainage water of sections for which they afford outlets. Every feasible plan and device has been used to circumvent the forces of nature and relieve valuable farm lands from surplus water. In the flat sections of our State nothing will serve this purpose but the deepening of our large sloughs by constructing capacious open ditches. Our land can not be properly drained without them. They must be of ample depth and width, and well made in every respect. No problem connected with the drainage interests of our State should, at present, receive more careful attention than this. Nature, has, in most cases, marked out the line for work, and says, "let man enlarge and complete for his undivided use according to his strength and skill." When such work is done, the demand for tile to supplement the drainage thus made possible will be unprecedented. The drainage of our roads will be facilitated, and the greatest difficulty thus far encountered in the drainage of our flat prairies will be overcome. Much has been attempted in this direction in some portions of the State, but many open ditches are too shallow, too small, and too carelessly made to serve the desired purpose. In pointing out some of the mistakes made in drainage, I am well aware that there are differences of opinion as to what may be properly considered a mistake. The aim of drainage is to fit the wet land of the entire farm for the successful cultivation of all the field crops at the least expense consistent with thoroughness. Now, if experiments must be tried by tiling here and there, and afterward take the tile up and remold the whole work, there is a loss which, were it not for the large profit resulting from the use of tile, would be disastrous. Should a Board of Public Works build several bridges of insufficient capacity in order to find out the necessary dimensions and strength of one which will serve their purpose, we should at once regard them incompetent and wasteful. I know of tile which have been taken up at three different times, larger tile being used each time. This farmer discards the use of lateral drains and rests his success upon single lines of large tile. He will probably be disappointed in this and, perhaps, finally hit upon the correct method. Would it not have been the part of wisdom to have obtained some reliable information upon that matter at first from books, from inquiring of others of longer experience, from a competent engineer, or from all of these sources? Anything which needlessly adds to the expense, or detracts from the efficiency of the work, should be regarded as a mistake. As a summary of what has been said regarding mistakes and how to avoid them, I append here a few DRAINAGE MAXIMS.