i;i i; \i. i.( ONOMI< 3. 



ment of this system and the locations of roads in such h way as to avoid the hills 

 and thus reduce grades. 



The necessity of drainage in order to secure ;i Bolid roadbed and to remove water 

 from the Burface of the roads is broughl out, and ii is recommended thai road 

 officials cooperate with drainage officials in providing for drainage. Tables are 

 riven Bhowing the areas which can be drained with differenl Bizes of tiles and open 

 ditches. Specifications for drains and prices for gradi en, and various 



machines for road construction and maintenance are described. The King road 

 drag, which consists of split logs or planks fastened together, i- especially recom- 

 mended for maintaining the surface of roads in proper condition. 



Directions for the construction and maintenance of dirt, gravel, and macadam 

 roads, and specifications for the construction of reinforced concrete culverts are 

 given. The results of traction tots on earth and -ravel roads and comparative 

 traction tests with wide and narrow -tired wagons are included. 



Road improvement in South Carolina, P. T. Bbodie I Clemson Agr. Col. Ext. 

 Work, 1(1905), No. 1, pp. 18-44, pis. 11). — This is a general discussion of the subjeel 

 of good roads, with some reference to South Carolina condition-. 



The average cosl of wagon hauling on the roads in the United State- i- estimated 

 at l*.*) cts. per ton mile, while the cost of hauling on good roads is estimated at 10 cts. 

 per ton mile. For improving South Carolina conditions it is recommended that 

 grades be reduced both by cutting and filling and by going around hills rather than 

 over them where this is necessary ; and by surfacing roads with a mixture of clay 

 and Band. A general discussion of construction of stone roads is also included. 



Petrol, paraffin, or alcohol for agricultural motors, 1 >. Albone (Marie Lam 

 Express, 93 I 1905), No. 3868, Farm Mach. and Tmpl., p. Ill I. — This gives the results 

 of experiments with an agricultural motor, using petrol, paraffin, and alcohol. A 

 single motor has been made which will use any one of these. The comparative 

 results were as follows: "With 2 gal. ofpetrol3 rood- of land were plowed: with 2 

 gal. of paraffin 2 roods. 35 poles were plowed: with 2 gal. of alcohol 2 rood-. 25 poles 

 were plowed." 



Modern refrigerating machinery; its construction, methods of working, 

 and industrial applications, 11. Lorenz, trans, by T. 11. Pope (New York: J. Wiley 

 A Sons; London: Chapman & Hall, Ltd., 1905, pp. X 396, figs. .-;/>.— This is 

 intended as a guide for engineers and owners oi refrigerating plants, and contains 

 chapters on the principles of the theory of heat, methods of cold production and 

 energy required, the construction of compressors, apparatus for giving oul and taking 

 nj » heat, the erection of absorption machines, the cooling of li pi ids and keeping them 

 cold, cooling air. manufacture of ice, production and application of cold at very 

 low temperatures, and determination of the yield of cooling machine-. There are 

 chapters on American practice in refrigeration, insulation, and auditorium and other 

 cooling, by II. M. Haven and F. \V. Dean. 



RURAL ECONOMICS. 



Contributions to the economics of agriculture, F. Abbbboe (Mitt. Landw. Inst. 

 Breslau, S (1905), No. S, pp. TV 311 157).— This monograph treats of the general 

 principles which underlie the organization of 'the farm in such a manner a- will 

 enable the farmer to Becure, one year with another, the best possible results. 



The factors of production land. Labor, and capital- are discussed from the stand- 

 point of the proper degree of intensity of culture. The various branches of agricul- 

 tural production, such as grain production, fodder production, and the various lines 

 of live-stock production, are discussed from the standpoints of their relation- to each 

 other and of the external conditions, such as the character of the soil and the local 

 market prices of the products, which determine the relative importance to be given 

 to each of these lines of production. 



