1917] RURAL ENGINEERING. 187 



and the encroachments of civilization. The benefits to be derived from a gen- 

 eral project desiijned to prevent the inundation of the bottom lands of the valley 

 as a whole would not, at the present time, be commensurate with the cost of 

 such work, but the annual damage sustained at Freeport and vicinity is suffi- 

 cient to warrant the outlay necessary to protect that city against a flood flow 

 of 21.000 cu. ft. per second, or nearly 25 per cent greater than that of March 

 28, 1916. This protection can best be accomplished by providing channel area 

 sufJicient to carry a flood of 21,000 cu. ft. per second with a slope of approxi- 

 mately 0.5 ft. per mile . . . and wdiere necessary constructing levees to 

 protect the low sections against overflow. The required cross section can be 

 most economically obtained by constructing an auxiliary channel." 



Tests indicate drain tile beddings increase strength (Enfiin. Rec, 15 

 (1917), No. 12, pp. 459, 460). — This is an abstract of a paper presented by 

 W. .1. Schlick before the American Concrete Pipe Association, in which tests 

 made at the Iowa Engineering Experiment Station are reported. These con- 

 sisted of bedding 24-in. drain and sewer tile in shallow trenches and then load- 

 ing them through a standard upper sand bedding. It was found that an in- 

 crease in strength of 25 per cent may be obtained by careful earth bedding and 

 as much as 90 per cent by certain forms of concrete bedding, especially in 

 solid soils. 



Report of hydrometric surveys (stream measurements), 1915, F. H. Pkters, 

 P. I\I. Sauder, et al. (Dept. Int. Canada, Irrig. Branch Rpt. Hi/droniet. Surveys, 

 1915, pp. y+590, pis. 13, figs. 10). — This report presents the results of measure- 

 ments of flow made on streams, irrigation ditches, and canals in Alberta and 

 Saskatchewan during 1915. 



Water supply, W. P. Mason (New York: John Wiley <£ Sons, 1916, 4- €d; 

 rev., pp. X+52S, pi. 1, figs. 129; rev. in Engin. News, 76 (1916), No. 25, p. llSl; 

 Amer. Jour. Pub. Health, 7 (1917), No. 2, p. 197). — This book contains chapters 

 on drinking water and disease; artificial purification of water; natural purifi- 

 cation of water; rain, ice, and snow; river and stream water; stored water; 

 ground water ; deep-seated water ; quantity of per capita daily supply ; and 

 action of water upon metals. Appendixes are included on analyses of sea 

 waters, rights and duties regarding the pollution of streams, and typhoid fever 

 contracted from drinking polluted water decided to be " an accident." 



In the chapter on drinking water, considerable space is devoted to the dis- 

 tribution of typhoid fever and factors operating in its transmission. Newly 

 developed methods of water purification, particularly processes aiming at disin- 

 fection, are considered, as are also certain recently discovered factors in- 

 fluencing natural purification in streams and stored waters. The use of chlorin, 

 ozone, ultra-violet light, and copper sulphate receive a good deal of attention, 

 and considerable space is also devoted to a discussion of various phases of the 

 pollution of drinking water supplies and the care of watersheds. 



Makawao waterworks for rural supply, J. B. Cox (Engin. News, 77 (1917), 

 No. 8, pp. SlO-312, figs. 2). — This is a description of a county water supply for 

 a rural district in Hawaii, which is maintained under tropical conditions. 



A simple method of water analysis, J. C. Theesh (London: J. & A. Church- 

 ill, 1915, 8. ed., pp. 69). — This book describes methods and equipment necessary 

 for simple chemical analysis of water and describes the chlorin method of 

 water purification, especially for residential or camp supplies. 



Direct microscopical counting of bacteria in water, B. E. Nelson (Jour. 

 Amer. Chem. Soc, S9 (1917), No. 3. pp. 515-523, fig. i).— Experiments are re- 

 ported, from which it is concluded that " direct microscopical counts of bac- 

 105033°— No. 2—17 7 



