RURAL ENGINEERING. 91 



lbs. and that for the partially dried bagasse, 2.53 lbs. This shows that 1 lb. 

 of the partially dried bagasse had a heat value of 55.2 per cent greater than 

 that of 1 lb. of wet bagasse. . . . 



" The average boiler efficiency for the tests with the dryer in use was 63.5 

 per cent, and that with undried bagasse, 50.7 per cent. The increased efficiency 

 with partially dried bagasse is probably due to less smoldering during combus- 

 tion and to higher furnace temperatures. Based on an equivalent evaporation 

 of 14 lbs. of water from and at 212° per pound of oil, the saving due to di-ying 

 was calculated to be 2.57 gal. of oil per ton of cane. . . . 



"The average temperature of gases entering the dryer was 474°, and that 

 leaving the dryer, 219°. The weight of bagasse handled per hour varied from 

 •686 to 3,150 lbs. The percentage of reduction in moisture seemed to be as 

 great with heavy as with light feeds. . . . The loss of heat from llie dryer 

 due to radiation was 8.3 per cent." 



Concrete silo construction, C. A. Ocock and F. M. White (Wisconsin Sta. 

 Bill. 214, pp. 3-31, figs. 18). — This bulletin gives directions in detail for the 

 construction of several types of concrete silos, especially the reinforced concrete 

 or monolithic silo. The authors state that the scarcity of lumber and its high 

 price in many localities is the factor which has emphasized the importance of 

 more permanent silos, and that reinforced concrete is equal if not superior to 

 all other materials used in the construction of silos. Tables are given showing 

 the relation of the size of the silo to the amount of silage to be used daily, and 

 the capacity of silos. 



Forms for solid-wall silos were found to cost from iflO to $70. In the con- 

 struction of a 6-in. wall reinforced concrete silo, 14 ft. inside diameter by 35 

 ft. high, on the University Farm in 1910, 50 bbls. cement, 28 yds. crushed stone, 

 and 16 yds. sand were used, the proportions used being 1 : 2J : 5. The rein- 

 forcement and galvanized iron for the door in the roof cost $25, the material 

 $129, doors $4.60, rent for staging $5, labor $159, making the total cost exclusive 

 of the forms $293. 



For reinforcement cables made by twisting together good grade No. 9 tele- 

 phone wire, thereby obtaining a rougher surface, are considered better than 

 smooth rods. Tables give the amount, size, and spacing of reinforcement, and 

 directions are given for placing it. In all cases the reinforcement should be 

 placed about 1^ to 2 in. from the outside of the wall. 



General directions are given for the construction of concrete-block silos, and 

 for a good homemade concrete-block machine, which is illustrated. Notes on 

 the stave silo, the Gurler silo, and the general care of silos are included. 



New uses of explosives in agriculture, F. H. Gunsolus (Jour. FranMin 

 hist., 172 (1911), No. 2, pi). 153-161, figs. 3; ads. in Jour. Soc. Chem. Indus., SO 

 (1911), No. 17, p. 1078). — This article refers to the well-known use of explo- 

 sives for clearing land, but devotes attention particularly to their use for the 

 preparation of soil for the planting of trees, the loosening of impervious sub- 

 soils, digging of ditches, and draining of ponds and swamps. Other purposes for 

 which explosives may be used with advantage are stated to be grading roads, 

 digging cellars, excavating trenches for foundations, pipe lines, tiling, etc., 

 digging holes for poles and fence posts, and sinking wells. 



Making electricity do the work on farm, C. A. Shamel (Orange Jiidd 

 Northwest Farmstead, 7 (1911), No. 16, pp. 32Jf, 325, figs. 5).— The installa- 

 tion and cost of maintenance are discussed of an electric power plant on an 

 Illinois farm. The plant furnishes electricity for operating farm machinery, 

 running washing machines and the churn, cookery, and other farm and house- 

 hold tasks. 



