384 EXPERIMENT STATION EECOKD. 



subjects as movable dams, hydraulic machinery, the hydraulics of contracting 

 and expanding pipes, valves and valve motions, water-hammer, ejectors, 

 siphons, the removal of air from siphons, air lifts, air compression, hydraulic 

 rams, resistance of motion of solid bodies in water, impact of water, turbines, 

 and centrifugal pumps. The work closes with a brief treatise on concrete, 

 iron, and other materials used in hydraulic construction. 



The area of waterways, J. Vicars (Rpt. Austral. Assoc. Adv. Sci., 13 {1911), 

 pp. 622-629). — The author endeavors to demonstrate the inadequacy of the 

 existing formulas for run-off used in determining the area of waterways for 

 carrying off storm water. In addition he presents his own formula, which he 

 beUeves embodies the primary essentials governing flood discharge and may be 

 applied to any locality. 



Loss of head due to bends in water pipes, W. E. Fuller (Canad. Engin., 

 26 (1914). A'o. 11. pp- -^'/i--J-'/.?, figs. Jf). — In this article the loss of head due to 

 90° bends is considered as that portion of the total loss in excess of the loss 

 which would occur in an equal length of straight pipe. Data from various 

 experiments indicate that the loss is more nearly the same for different sizes 

 of pipe with bends of the same actual radius in feet than for the bends of 

 the same radius in terms of pipe diameters. 



Average values of the loss of head for different velocities due to bends of 

 the same radius show that the loss is proportional to tr^-^'\ from which the 

 formula hb=kv'^-'^^ is deducted in which hb is the loss of head, Z; is a coefficient 

 varying with the radius of bend, and v equals the velocity. 



The computations in which the actual lengths of the tangents to the curve 

 were assumed as the straight pipe brought out the following points : The excess 

 loss of head in bends is greater for large pipes than for small ones, and for 

 large pipes a 6-foot radius bend gives the least resistance unless very long 

 radii are used. " For small pipes . . . with long radii the loss of head will be 

 less than it would be in straight pipe of a length equal to the tangents of the 

 curve." For losses due to 45° bends it is suggested that three-fourths of that 

 due to 90° bends of the same radius be used ; for 22.5° one-half, and for a Y- 

 branch three-fourths of that due to a T. 



Drainage and irrigation : Drainage ditch and levee tables for level section 

 with explanation of method* of computation, E. S. Blaine (Engin. and 

 Contract., Jfl (1914), No. 10, pp. 302-306, fig. 1).—K table is given of volumes of 

 excavation in cubic yards per 100 linear feet of ditch in level sections, having 

 side slopes of 1 on 1 and bottom widths of from 4 to 123 ft. The volumes are 

 calculated to correspond to tenths of feet in depth. The method of computation 

 was by use of second differences, calculating them by addition within the 

 limits of the table. A demonstration shows that the second difference not 

 only remains constant for prisms having the same slope, but also that the second 

 differences for other slopes are a multiple of this quantity if the slopes are 

 the same on both sides of the section. If not the same, then it is a multiple 

 of the average of the two slopes. 



Drainage and irrigation : Linings for small storage reservoirs, C. R. 

 Sessions (Engin. and Contract., 41 (1914), ^^o. 10. pp. 304-306).— The author 

 discusses clay, plastered cobble, concrete, and asphaltum and oil linings for 

 small storage reservoirs, but is of the opinion that of these the clay puddle 

 lining is probably the cheapest and best. 



Machine for testing drain tile, D. A. Abeam s (Engin. News, 71 (1914), No. 

 12, p. 614, fiff- i)- — A tile testing machine which is used in the laboratory of 

 applied mechanics of the University of Illinois is illustrated and its construction 

 and operation briefly described. 



