390 EXPERIMENT STAIION KECOED. [Vol. 36 



horsepoAver motoi* running at 400 to 750 revolutions per minute ai'e reported. 

 The grade of the red clay soil varied from nearly level to from 25 to 30 per cent. 



The tractor was unable to pull a 3-bottom gang plow uphill effectively but 

 pulled a 2-bottom plow both ways. The 3-bottom plow, covering a width of 

 1.05 meters (3.44 feet), was pulled downhill. In the residual soil with easy 

 slope the tractor drew a double-bottom plow at a depth of 27 cm. (10.5 in.) 

 and covered a width of 33 cm. Six oxen plowed the same width but only 25 

 cm. deep. The tractor plowed 1,056 square meters (0.26 acre) per hour and 

 hauled a 16-toothed scarifier and a 3-piece harrow. It traveled twice as fast 

 as oxen and it is considered to have replaced eight pairs of oxen and six men 

 in the amount of work done. 



Twenty-three liters (6 gal.) of petrol were burned in the engine in 2f hours, 

 of which If hours were consumed in actual work and the other hour in stops 

 and travel. 



Plans and suggestions for the arrangement and construction of a modern 

 milk house ( [Neiv York], Borden's Condensed Milk Co., 1916, pp. 32, figs. 33). — 

 I'lans and descriptions of milk houses and ice houses for dairy farms are given. 



Inexpensive plumbing for farm kitchens, W. A. Ethekton (Kans. Agr. Col. 

 Ext. Bui. 9 {1916), pp. 23, figs. 7). — This bulletin describes plumbing systems 

 for farm kitchens based on the method of using a force pump and three-way 

 cocks described in a previous article (E. S. R., 35, p. 496). 



The operation of a simple system of the type is described, showing how cold 

 and hot water may be pumped and water siphoned from the hot water boiler to 

 the sink or back to the cistern. A combination system using an attic tank or a 

 pressure tank with this system is also described, together with fittings for 

 shower baths, etc. A third section itemizes and explains the parts of the appa- 

 ratus. A final section on cost, based on conditions in Kansas in April, 1916, is 

 included. 



The water supply of the farmhouse, J. D. Walters {Kans. Agr. Col. Ext. 

 Bui. 10 {1916), pp. Jf2, figs. 15). — This is a semipopular bulletin, based on 

 Kansas conditions, containing sections on the following subjects related to farm 

 water supplies : Amount of water required ; spring water and well water ; wells ; 

 contamination of wells ; artesian wells ; filtering the cistern water ; pumps, lifts, 

 and rams ; power required to lift water ; theoretical horsepower ; the windmill ; 

 the water tank ; the concrete reservoir ; the water tower ; the air-pressure tank ; 

 compressed air lifts ; soft water for the laundry and the bathroom ; the auto- 

 matic water lift; the hydraulic ram; the friction element in plumbing; and 

 cheap home ice. 



Water supply systems for the farm home, H. W. Riley {Cornell Country- 

 man, 13 {1916), Nos. 7, pp. 566-569, figs. 3: 8, pp. 665-668. 690, 692, figs. ^).— A 

 brief description of hydropneumatic and pneumatic tank water supplies is 

 given, together with a discussion of the hydraulic principles involved in pump- 

 ing and distributing water for small systems. 



Sewage treatment in small communities without sewerage systems, P. 

 Hansen {Univ. III. Bui., 13 {1916), No. 19, pp. 189-195, figs. 5).— Small sewage 

 purification systems, consisting of settling ttink and tile absorption areas of 

 sufficient size to meet temporarily the requirements of small communities, are 

 briefly described and illustrated. 



RURAL ECONOMICS. 



Agricultural economics, E. G. Nottk.se {Chicago: Univ. Chicago Press, 1916, 

 pp. XXV+896. figs. 23). — "This volume represents an effort to carry over into 

 agricultural economics some results of recent experience in the use of the dis- 



