Author : Joseph Alexander Jeffery
Release : 2013-09
Genre :
Kind :
Book Rating : 585/5 ( reviews)

GET EBOOK

Text-Book of Land Drainage - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Text-Book of Land Drainage write by Joseph Alexander Jeffery. This book was released on 2013-09. Text-Book of Land Drainage available in PDF, EPUB and Kindle. 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. 1916 edition. Excerpt: ...drain, as described in paragraph 146, excepting that the laterals discharge at their lower terminal into the main or sub-main, and not at an outlet. It is most convenient to drive the grade stakes at intervals of 50 feet, for reasons given in paragraph 147, and for the further reason that a greater distance than 50 feet increases the difficulty in using the boning line. 154. The angle of approach for laterals.--It is common, in systems like that illustrated in Fig. 25, to locate the laterals so that their upper angle to the main shall be less than 90 degrees. If, however, it should be deemed advisable to run the lateral at right angles to the main, as shown in Fig. 26, then they should be turned slightly as they approach the main so as to enter at an angle of less than 90 degrees, the reason being that if the water from the lateral is discharged into the main at an angle of 90 degrees, it is likely to interfere with the movements of the water and also with the ready movement of the silt which may be carried by the waters of the main. Another factor, however, that must enter into the angle of approach is the position and shape of the area requiring drainage. (See Figs. 28 and 29.) The angle of approach must be determined by the needs of the land and economy i in labor. The angle of discharge should be governed by the suggestions above. 155. The location of the upper end of mains and laterals.--It is not necessary to carry the end of either main or lateral to the very edge of the area to be drained. The water in the soil will move toward the end as readily as it will toward any other point in the drain. The line of equal influence of the drain at this point is the arc of a circle whose center is the end of the drain. 156. Measurements.--Due...