1917] RUEAL ENGINEERING. 783 



the internal organs, even wJien quantities exceeding those employed in working 

 with the disease in geese are used. It is found, however, in the central 

 nervous system. 



" The transmission of the infection to fowls is possible by means of sub- 

 cutaneous injection of emulsions of the cerebral substance of infected ducks. 

 On the contrary it is not possible to transmit it to the domesticated duck 

 however large a dose of virus is employed, either by ingestion, intravenous 

 inoculation, instillation on to the conjunctiva, or even by intracerebral in- 

 oculation." 



RURAL ENGINEERING. 



Hydraulic flow reviev^ed, A. A. Barnes {New York: Span d Chamherlnin, 

 1916. pp. XI+158, pl'^. 12, figs. 1.5). — This is a book of reference to standard 

 experiments on the flow of water in pipes, channels, notches, weirs, and circular 

 orifices, together with new formulas relating thereto derived from the author's 

 experiments. 



Part 1 deals with the experimental determination of the coefficients in the 

 logarithmic formula for the flow of water in various kinds of pipes and chan- 

 nels. Part 2 deals with the measurement of water by means of triangular 

 notches, weirs, and circular orifices, and with the abolition of the varying 

 coefficient. 



From his experiments the author draws the conclusion that flowing water 

 always obeys one fundamental law. "As distinct from the various types of 

 formulas which at present exist for representing isolated sets of results these 

 new equations form one family, the individual members are all descended 

 from the fundamental formula : v=K m" H^. Further, this equation is directly 

 related to the formula for all classes of pipes and channels in which the in- 

 troduction of the length in the direction of flow merely causes the formula to 



be written : v=K m"' j/3, in which i=^." 



Li 



A bibliography and working tables and diagrams are included. 



A striking feature of this book is that no recognition is given certain 

 recent American works bearing on the subject, especially those from the U. S. 

 Reclamation Service and the U. S. Department of Agriculture. 



Hydro-electric power. — -I, Hydraulic development and equipment, L. Lyn- 

 don {Nexc York: McGraw-Hill Book Co., 1916, vol. 1, pp. VII+499, pi. 1, figs. 

 234). — It is the author's purpose in this book " to produce a work for the guid- 

 ance of engineers in the practical design of hydroelectric plants, which would 

 have the characteristics of accuracy, clearness, and completeness. Scientific 

 discussions of various hypotheses and theories have been omitted except in 

 cases where their incorporation in the text has been essential to the under- 

 standing of the subjects treated. ... A number of new and original for- 

 mulas appear for the first time here. Among these may be mentioned the 

 exact formulas for solid dams and for the magnitude and location of the 

 resultants of forces acting on dams." 



The successive chapters are as follows : General conditions, flow in streams, 

 weirs and orifices, power variation and storage, artificial waterways, pipe lines 

 and penstocks, dams, movable crests for dams, headworks, water wheels, and 

 speed regulation of vi'ater wheels and abnormal penstock pressures. Mathe- 

 matical tables for practical use are appended. 



Convenient form of hook gage, R. B. Sleight {Engin. Neics, 77 {1911), No. 

 4, pp. 15.5, 156, figs. 2).- — This article describes and illustrates a convenient hook 

 gage developed by the Office of Public Roads and Rural Engineering of the 

 TJ. S. Department of Agriculture and used by its Irrigation Investigations 

 Division. 



