790 EXPEKIMENT STATION RECORD. 



gives suggestions for the installation of a residential plant consisting of three 

 chambers, a grit chamber, a settling compartment, and a discharge chamber. 

 Final disposal by discharging into an underground pipe absorption system is 

 i-ecommeuded where possible, but when the soil is wet, heavy, or of a clay 

 nature, it is suggested that the contents of the discharge chamber be siphoned 

 into an underground filter of broken stone and gravel and from there to a 

 second filter of sand. From this it is necessary to pump the filtered water at 

 stated intervals. 



"Water, its properties and practical uses. — XXI, [Installation of house 

 and subsoil drains and cellar drainers], F. W. Tower {Dom. Engin., 65 {191S), 

 A'o. 12, pp. 868-371, figs. 3). — This article deals with the design and installation 

 of house sewer plumbing and diagrammatically illustrates and describes subsoil 

 drains and cellar drainers. A velocity of 275 ft. per minute is considered de- 

 sirable in house drains in order to clear all dndns of solids and refuse. 



Septic tanks and sewage disposal {Dom. Engin., 65 {1913), No. 11, pp. S3(h 

 334, fiV^- ^^)' — The subject of sewage disjK'sai is reviewed and the operation of 

 septic tanks and disposal systems briefly described. 



School hyg-iene, F. B. Dresslar {New York, 1913, pp. XI +369, figs. 51).— 

 The topics discussed in this book cover nearly the whole field of school sanita- 

 tion and the health of school children, among the more prominent being those 

 dealing with the location, construction, and equipment of school buildings, com- 

 mon physical defects and need of medical inspection of school children, and 

 recent pedagogical theories regarding play, home work, etc. While many of 

 the statements refer chiefly to city schools, many others apply equally to rural 

 schools, and the water supply and sanitary equipment of the latter are espe- 

 cially discussed. 



Experiments in school room ventilation with reduced air supply throug-h 

 individual ducts, F. Bass {Heating and Ventilating Mag., 10 {1913), No. 8, 

 pp. 16-2Jf, figs. 11; Amer. Jour. Puh. Health, 3 {1913), No. 11, pp. 1135-1137).— 

 The results of an experiment on the recirculation of air and the use of ozone 

 in school ventilation indicate that in an average school reci'.-culation and re- 

 newal of the air for three weeks is an esthetic and hygienic possibility and 

 will effect heating economy. 



Some preliminary studies in air washing- and its results, G. C. and M. C. 

 Whipple {Amer. Jour. Puh. Health, 3 {1913), No. 11, pp. 1138-1153) .—'E^i^eTi- 

 ments in air washing showed that about two-thirds of the suspended particles, 

 including dust, bacteria, and molds, were removed by this process. It is be- 

 lieved that air washing is one of the vital elements of ventilation in localities 

 where a clean supply of air is difficult to obtain, and that the recirculation 

 of such air is deserving of serious consideration from the standpoint of heating 

 economy, especially in cold climates. 



Concrete garbage burners {Irrig. Age, 29 {1913), No. 2, p. 52, figs. 2). — Two 

 small concrete garbage burners for use on the farm are illustrated and briefly 

 described. 



RURAL ECONOMICS. 



The census methods of the future. — Agricultural statistics, E. D. Durand 

 {Quart. Puhs. Amer. Statis. Assoc, n. ser., IS {1913), No. 104, PP- 568-573).— 

 The author concludes that it seems desirable in the future to employ the rural 

 mail carrier to collect federal agricultural statistics; to obtain annually by 

 actual enumeration the numbers of dom.estic animals and the acreage and produc- 

 tion of the principal crops; to distribute part at least of those inquiries which 

 i»eed to be asked only at decennial intetvals among the individual years of the 



