1916] RURAL ENGINEERING. 81 



pp. 196-206). — This material has been previously noted from another source 

 (E. S. R., 31, p. 485). 



On the anatoray of a fowl tapeworm, Amoebotaenia sphenoid.es, F. J. 

 Meggitt {Parasitology, 7 (1914), No. 3, pp. 262-277, pis. 2).— In addition to the 

 anatomy the author briefly considers the life history of this parasite. 



RTJRAL ENGINEERING. 



A new irrigation weir, V. M. Cone {U. S. Dept. Agr., Jour. Agr. Research, 



5 {1916), No. 24, pp. 1127-1143, figs. 16). — Experiments conducted under a co- 

 operative agreement between the Office of Experiment Stations and the Colo- 

 rado Experiment Station are reported. The purpose was to develop a weir 

 " that would be self -cleaning, require a minimum amount of labor and material 

 for construction, measure discharges with an accuracy commensurate with 

 field conditions and irrigation demands, and be easily operated by the ordinary 

 man." 



Altogether 277 experiments were made with a new type of weir using both 

 rectangular and 90°-triangular notches. Thirty-four different arrangements of 

 weir box were used for the rectangular notches, the length of weir crest 

 varying from 1 to 4 ft., and the width of weir box at both the crest and 20 ft. 

 from 1.5 to 6 times the length of crest. Floor lengths of 32.67 and 20 ft. were 

 used. From the results a weir was developed, the general formula for the 

 discharge of which is 0-==(3.S3— 0.7L) Lh (1.52-fO.OlL) in which C)-=the dis- 

 charge, L=the length of crest, and Zi^the head on the weir. The computed 

 dischurgos for the new weirs are given in tabular form. 



The tests brought out the following advantages : " The new irrigation weir 

 is self-cleaning. ... No lowering of the canal grade or building up of the 

 banks is required for the construction of the weir box. The weir box has only 

 one-fourth the depth and a less width than is required for a full-contraction 

 weir. Less excavation and less materials are needed in the construction, and 

 the cost of the weir is therefore greatly decreased. It may be installed by the 

 farmer witliout expert assistance and with the tools ordinarily at hand. Its 

 operation does not require special training. Its accuracy is consistent with 

 practical demands and will remain constant. It can not be easily tampered 

 with or accidentally injured so as to alter its discharge. There are no work- 

 ing parts which require attention for proper operation. There is practically 

 no upkeep expense if the weir is well constructed of durable materials. When 

 the discharge tables are used, no computations are required." 



Specifications for the construction and use of the new weir are as follows: 

 " The weir notch is rectangular in form, with sharp crest and sides. The 

 floor of the weir box must be level with the crest. . . . The grade of the 

 canal downstream from the weir must be low enough to give free fall and 

 complete aeration to the nappe. The floor of the weir box must be level 

 throughout, and there must be no sudden or decided differences in elevation 

 between the floor and the grade of the channel of approach. The. weir box 

 must be placed in the center of the ditch, so the axial line of the box corre- 

 sponds with the axial line of the canal, in order that the water may enter the 

 weir box in straight lines. The width of the weir box must be twice the length 

 of the weir crest at the plane of the weir, and two and a half times the length 

 of the weir crest at a distance of 20 ft. upstream from the plane of the 

 weir. . . . 



" It is necessary that a still box be placed outside the weir box and con- 

 nected through the side of the weir box with one or more 1-in. pipes located 



6 ft. from the plane of the weir. The pipe should be placed near the floor 



