. Engineering for land drainage. A manual for laying out and constructing drains for the improvement of agricultural lands. Drainage. OPEN DRAINS. 15S While circular curves may be used to describe ap- proximately the curvature that should be given, the true form should not be geometrical, but rather what may be termed natural, or such as is used in laying out artificial streams and roads in parks, in which geo- metrical lines are ignored. The difference between the two is shown in Fig. 29, which is a 12-degree curve. Fig. 29.—^Proper Curve for Open Ditches. (radius 478 feet) varied so as to su

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. Engineering for land drainage. A manual for laying out and constructing drains for the improvement of agricultural lands. Drainage. OPEN DRAINS. 15S While circular curves may be used to describe ap- proximately the curvature that should be given, the true form should not be geometrical, but rather what may be termed natural, or such as is used in laying out artificial streams and roads in parks, in which geo- metrical lines are ignored. The difference between the two is shown in Fig. 29, which is a 12-degree curve. Fig. 29.—^Proper Curve for Open Ditches. (radius 478 feet) varied so as to su
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Image ID: PFXN3X
. Engineering for land drainage. A manual for laying out and constructing drains for the improvement of agricultural lands. Drainage. OPEN DRAINS. 15S While circular curves may be used to describe ap- proximately the curvature that should be given, the true form should not be geometrical, but rather what may be termed natural, or such as is used in laying out artificial streams and roads in parks, in which geo- metrical lines are ignored. The difference between the two is shown in Fig. 29, which is a 12-degree curve. Fig. 29.—^Proper Curve for Open Ditches. (radius 478 feet) varied so as to subject the bank against which the stream strikes when first deflected to the least possible erosion. The reason for this is well illus- trated by Fig. 30, in which the stream is represented as being divided into filaments, each having a velocity imparted to it by the flow, and striking the opposite bank as an individual force. According to the well- known law of force, the angles of incidence and reflec- tion are equal when a force meets a resisting plane. Hence in the case under consideration, the reflected. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Elliott, Charles Gleason, 1850-1926. New York, J. Wiley