1019] RURAL, ENGINEERING. 587 



in^s and brief specifications for individual and centralized hog houses prepared 

 with reference to Indiana conditions. 



Silos and silage in Arkansas, H. E. Dvorachek {Arkansa-'i Sta. Bui. 164 

 (1919), pp. 3-16). — This bulletin discusses the various types of silos in common 

 use, and gives general information on their construction with special reference 

 to Arkansas conditions. 



Stall construction, H. H. Musselman {Michigan Sta. Quart. Bui, 2 {1919), 

 No. 1, pp. 35, 36, fig. 1). — The details of construction of a cow stall built of 

 concrete, steel, and wood are illustrated and briefly described. 



Greenhouse heating, A. G. King {Dom. Engin., 88 {1919), No. 8, pp. 340-342, 

 figs. 5). — Information is given on estimating for and installing heating appa- 

 ratus for greenhouses, including diagrammatic illustrations. 



Cost of and revenue from electric heating on the Minidoka project, B. 

 Dibble {Reclam. Rec. [U. S.], 10 {1919), No. 2, pp. 78-8i).— This is an analysis 

 cf the cost of domestic electric heating for all the towns and isolated residences 

 on the Minidoka irrigation project using power supplied by the project generat- 

 ing station. 



" The indications are that electricity at $2 per month per kilowatt will com- 

 pete with coal at $8 per ton. It has been found on the Minidoka project that 

 the average season for the heating load is from five to six months. In other 

 words, the total consumption of electricity for heating is equivalent to five or 

 six months' continuous use of the maximum demand. Therefore a retail reve- 

 nue can be expected from this business of from $10 to $12 per kilowatt per 

 season." 



" It can be said that electric heating is sometimes justified as a ' by-product ' 

 load, but that rarely, if ever, will it be economically feasible to develop elec- 

 tricity from water power for the prime purpose of using it generally to heat 

 buildings where fuel can be obtained at reasonable prices." 



Analysis of electric cooking situation, S. M. Kennedy {Elect. ^Vorld, 72 

 {1918), No. 8, pp. 351, 352). — An analysis of the electric cooking load of a cen- 

 tral station in southern California supplying over 3,000 electric ranges, of which 

 95 per cent are in private houses, showed that (1) the electric cooking load 

 is a desirable load, (2) the electric range is satisfactory to its consumers, and 

 (3) electric cooking service is along the lines of conservation of both food 

 and fuel. The average annual bill for electric cooking on this system is said to 

 be about $4.5, and for combination cooking and water heating the average is $75. 



The relative merits of cast-iron, wrought-iron, and steel pipe for house 

 drainage purposes, W. P. Gerhard {Jour. Franklin Inst., 187 {1919), No. 1, pp. 

 90-109, figs. 8). — Fracture, threading, corrosion, acid, manganese, and micro- 

 scopic tests of cast-iron, wrought-iron, and steel pipe were conducted from 

 which it was found that " extra heavy cast-iron soil pipe is a satisfactory ma- 

 terial from the corrosion point of view. It is unsatisfactory as regards the 

 calked joints. These become affected by changes in temperature, and do not 

 remain tight under all conditions of service. The screw joint of welded pipe 

 is superior to the calked joint, provided the threads are so cut and the recessed 

 drainage fittings so tapped that the pipe can be screwed well into the shoulder 

 of the fitting. Portions of the thread remaining exposed to view should be 

 protected against external corrosion. The evidence furnished by the investiga- 

 tion leaves no doubt as to genuine wrought-iron pipe being a far more durable 

 material for house drainage pui-poses than steel pipe." 



Rural methods of waste disposal, H. D. Evans {Bui. State Dept. Health 

 Maine, n. ser., 2 {1919), No. 1, pp. 2^, fig.s. 12).— This bulletin deals briefly with 

 design and construction of sanitary privies, sewage tanks, and absorption 

 areas, with special reference to Maine conditions. The pail privy is considered 



