^«19] RURAL. ENGINEERING. 687 



tions like those In the Third Creek drainage area, drainage improvements 

 should provide for a run-off of 0.75 to 1 in. depth per 24 hours. 



Floods and water-logged land: The Land Drainage Act, 1918 (Jour. Bd. 

 Agr. [London^, 25 (1918), No. 8, pp. 961-968} .—This is a brief summary of the 

 changes made and the facilities afforded by the new Land Drainage Act in 

 England and Wales. This act is intended to facilitate the establishment of 

 drainage boards, to render possible a revision of drainage areas to suit modern 

 conditions, and to assist otherwise in the renewal and extension of arterial 

 drainage, including such matters as determining benefits and benefit assess- 

 ments. 



Moor drainage, W. Freckmann (Mitt. Ver. Ford. Moorkult. Deut. Reiche, S6 

 (1918), No. 23, pp. 379-382). — Six years' experiments with open ditches, pole 

 bundle drains, lath drains, plain tile drains, tile drains with plastered joints, 

 and tile drains laid on laths in a coarse-grained alluvial sand soil are reported. 

 Oats, beans, barley, beets, and rye were planted on soil with underdrainage, and 

 oats, wheat, beets, and potatoes on soil drained with open ditches. 



It was found that pipe drains laid on laths gave the most intensive drainage. 

 Plain pipe drains gave almost as good results, but are not considered as satis- 

 factory for moor soils owing to the fouling of the pipes. The pipe drains with 

 plastered joints, designed to prevent the fouling of the pipes by roots, etc., 

 gave only slightly less effective results than the pipe drains laid on laths. 

 The lath drain gave considerably less favorable results than the pipe drain on 

 laths. The pole bundle drains gave the least effective results. Open ditches 

 about 4 ft. deep and about 80 ft. apart gave approximately the same results as 

 pipe drains laid on laths and spaced about 40 ft. apart. 



With reference to crop yields a general improvement on all drained soils was 

 noted. The conditions governing this were, however, too variable to permit 

 judgment of types of drains on this basis. 



Hydraulic efficiency of a drainage ditch for five different channel condi- 

 tions, C. E. Ramser {Engin. News-Rec, 82 {1919), No. 11, pp. 522, 523, figs. 5). 



Experiments to determine the values of n in Kutter's formula, made on five 

 courses of the South Forked Deer River in Tennessee, are reported. 



The channels along these courses varied from a newly dredged channel in 

 excellent condition to a very crooked course of the old channel in very bad 

 condition. The lowest values of n were obtained In the new, straight, and 

 uniform channel. The effect of roughness and irregularities is shown in a 

 considerably increased value of n. " The values of n for the discharge of 715.1 

 sec.-ft. are 0.0367, 0.0619, and 0.146 for the dredged, old straight, and old 

 crooked channels, respectively, and the slope of the water surface required for 

 this discharge was over three times as much for the old straight as for the 

 dredged channel. . . . The difference in the relative capacities of the old 

 straight and the old crooked channels is not due entirely to the curves in the 

 latter, since the accumulation of trees, logs, and other drift was greater in the 

 crooked channel. However, the difference in the condition of the two channels 

 may be directly attributed to the presence of the curves, since there is a greater 

 tendency for drift and obstructions to accumulate in a curved than in a 

 straight course of channel." 



Canal seepage losses are affected by temperature, L. Crandall {Engin. 

 News-Rec, 82 {1919), No. 7, pp. 323, 324, flffs. 2). — Data from seepage investiga- 

 tions on canals of a western irrigation project comprising some 2,600 acres of 

 wet surface are reported. These show that the seepage losses increase with 

 149863°— 20 7 



