292 EXPERIMEXT STATION EECOED, 



Results of some experiments made to determine the effect of varying' the 

 percentage of water in concrete (Engin. and Contract., .'{2 (1914), A'o. 11, pp. 

 2Jf-'f-2'i6, figs. Jf). — The results of a series of experiments, using 6-iu. cubes 

 and reinforced beams 2 in. by 2 in. by 3 ft. of a 1: 2: 4 mixture and a water 

 content varying from 20 to 42.5 per cent of the weight of the cement, are 

 reported. The cubes were broken at the end of 7. 30, and GO days and the 

 beams at the end of 30 and 60 days. The beams were reinforced with two 

 J-in. round rods and designe<l to carry a load of 274 lbs. placed at the center 

 of the siian. 



In breaking the cubes the 27.5 per cent of water mixture appeared to be 

 the most desirable as regards strength. A drier mixture than this was notice- 

 ably weaker and a slight increase in the amount of water resulted in a decided 

 decrease in strength. In breaking the beams the 27.5 per cent of water mixture 

 also proved the strongest, b^th at the end of 30 and GO days. The relative 

 strength of the concrete beams vnrietl as regards the water percentage, and was 

 practically the same as in the cubes of the same consistency. 



Tensile tests of mortar briquettes containing 20 oz. of sand and 12 oz. of 

 cement showed that the mixture which gave the maximum strength was a 

 trifle drier, containing 25 per cent of water against 27.5 per cent for the beam 

 and cube tests, but the general relation of consistency to strength was the 

 same. 



RURAL ECONOMICS. 



The organization of a rural community, T. N. Carver (U. .?. Dcpt. Agr. 

 Yearbook 1914, pp. 89-13S, figs. 2). — The author presents a plan for the organ- 

 ization of a rural community, intended as a general guide for those interested. 

 He classifies the needs of rural communities which require organization as busi- 

 ness needs and social needs. Under each of these he h;is selected five major 

 needs, for each of which he suggests the appointment of a special committee. 



The committees on business interests are those on farm production, market- 

 ing, securing farm supplies, farm finance and accounts, and communication and 

 transportation. Those on social interests are on education, sanitation, recrea- 

 tion, beautification, and household economics. There is also a central com- 

 mittee consisting of the officers of organization and the chairmen of the various 

 committees. 



Concerning the organization of agricultural enterprises (Bol. Agr. T^c. y 

 Econ.. 6 {1914), Xo-s. 67, pp. 610-620; 68, 702-712; 69, 818-827; 70, 915-924; 71, 

 1001-1011; 72. 1097-1107).— These articles relate to the type of agriculture 

 found in Spain, and suggest reforms to make it more efficient. 



Information on rural economy and administrative organization of agri- 

 culture {Brussels: M. Weissenhnich, 1913. pp. 4S, pis. .5). — This report contains 

 a brief description of the various activities of the department of agriculture in 

 Belgium. It relates principally to methods used in improving the live stock, 

 controlling animal diseases, and can-ying on educational work in agriculture 

 and home economics and experimental work. 



[Winter agricultural work], A. Hofmeister {Mitt. Dent. Landtc. Gesell.. 29 

 (1914), Nos. .J7, pp. 637-639; 48, pp. 6-iS-650; 49, pp. 661, 662; 51, pp. 688-691).— 

 This article indicates methods that may be used to keep the men and women on 

 farms fully employed at profitable work during the winter season. 



The cost of production on Missouri farms, O. R. Johnson and W. E. Foabd 

 (Missouri Sta. Bui. 125 (1915), pp. 287-316. figs, o).— The authors outline their 

 method of investigation and indicate the cost per acre of the principal crops 



