EURAL EKGINEEEING. 387 



the in-emises and that all infested coops or crates be thoroughly treated with a 

 suitable insecticide. Somewhat encouraging results were obtained in treating 

 affected fowls with atoxyl and quiniu. 



RURAL ENGINEERING. 



Practical irrigation; its value and cost, A. J. Bowie, Jr., {New York, JDOS, 

 1,1). y 111+232, figs. 53). — This book deals with certain phases of the subject 

 of water supply for irrigation rather than with the use of water in irrigation, 

 and the greater part of it is devoted to wells, pumps and pumping machinery, 

 and storage reservoirs. 



About one-third of the space is given to artificial reservoirs made entirely 

 in embankments. Such reservoirs are not in general use, but in the author's 

 opinion there is a large field for their use in storing water where natural reser- 

 voir sites are not available. Formulas, curves and tables for computing water 

 holding capacity, cubic contents of embankments, and cost are given. 



In addition to the subjects treated at length, mentioned above, there are 

 brief discussions of methods of irrigation, evaporation, flow of water in ditches, 

 methods of charging for w'ater, and irrigation near Bakersfield, Cal. In gen- 

 eral, the book consists of miscellaneous observations on the subjects discussed. 

 The treatment of all subjects is mathematical, the book containing many 

 hydraulic formulas and tables. 



Reports upon the administration of the irrig'ation services in Egypt and 

 in the Sudan for the year 1906 (Cairo: Govt., 1907, pp. 58, pis. J, dgins. 2, 

 charts 2). — This report consists of a general report by Sir William Garstin, 

 adviser to the ministry of public works, and detailed administrative reports 

 by A. L. Webb, under secretary of state for Irrigation in Egypt, and C. E. 

 Dupuis, inspector-general of irrigation in the Sudan. 



The report shows large increases in the area devoted to cotton and the state- 

 ment is made that this increase will continue so long as the present prices of 

 cotton are maintained. This increase is made possible by the change from the 

 basin system to perennial irrigation depending upon the Assuan dam. It is 

 now estimated that the conversion works in Middle Egypt will, when completed, 

 provide perennial irrigation for about 420,000 acres, formerly included in basins, 

 at a total cost of about $21,000,000, or approximately $.50 per acre. On the 

 basis of work so far done this will increase the rental value of the lands about 

 $21 per acre and the selling value about $275 per acre. The author states that 

 while these figures may seem large they are in no w'ay exaggerated. 



It has been found that the floods discharged by the Assuan dam have eroded 

 the channel below the dam, the pits in some cases going below the foundation 

 of the dam and rendering it unsafe. This damage has been repaired by blast- 

 ing out the rotten rock, filling the holes with masonry, and constructing an 

 apron below the dam which modifies the discharge of the water from the sluice 

 in such a way that no erosion takes place. It is considered that since these 

 reiiairs there is no danger to the dam from this source. 



The work done in the Sudan consisted entirely of surveys preliminary to the 

 making of plans for the improvement of the headwaters of the Nile. The object 

 to be attained is the prevention of losses into the marshes during low water 

 without destroying their usefulness as an escape for flood water. The sur- 

 veys have not proceeded far enough to allow the formulation of any definite 

 plans for accomplishing this. 



Experiments in irrigation, Gerlach and KRiJGER (Arb. Dent. Landio. Gcscll., 

 1008, No. 1.1,1, pp. 52, pis. 8, figs. 2). — This is an account of experiments carried 

 on at the Kaiser Wilhelm Institute at Bromberg during the dry year of 1906 

 61717— No. 4— OS 7 



