Practical Farm Drainage; A Manual for Farmer and Student - Charles Gleason Elliott

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 edition. Excerpt: ...successively during twenty-four, forty-eight, or sixty hours, it is observed that heavy precipitation during short periods occurs in localities where the annual rainfall is large, though this is not always true. However, the amount of annual precipitation may be used as an approximate guide in determining the sizes of tiles that should be used for mains. The number of acres given in the table for which the sizes of tile opposite will afford an outlet should be varied to meet the rainfall conditions of different sections by the use of the following factors: Where the annual rainfall is 50 in. multiply acres in table bv.8...., . 55. ." u u y "60" " " .""6 "30" " " ""1.2 it tt tt tt a 2" tc te 11 "14 The office of lateral drains we have seen is to collect the excess of water from the soil and deliver it to the mains. As before shown, it is necessary to place these at different distances apart and according to various plans, depending upon both surface and soil, to get the desired result. The size of the tiles in the lateral system is governed in part by the grades upon which they are laid. To secure the best drainage, laterals should rarely be filled. Ample size will facilitate aeration of soil and render constant the conditions which favor activity of soil bacteria, those important agents in the development of soil fertility. Where soil is retentive, requiring drains as frequent as forty to sixty feet, three-inch tile may be used. For greater distances, and more open soils, no smaller than four-inch are admissible, while five-inch and six-inch may be necessary under conditions where the laterals are practically submains to supplement natural drainage. In describing...