RUKAL ECONOMICS. 89 



and openite as many hours per day as possible in order to cut down the ix)wer 

 company's plant investment and increase the return per unit of installed 

 capacity. 



Traction farming and traction engineering-, J. H. Stephenson (Chicago, 

 1913, pp. 330, figs. 151). — This is a practical handbook for owners and operators 

 of gasoline, alcohol, and kerosene engines on the farm, comprising descrip- 

 tions of some of the makes of farm tractors with directions for their care and 

 operation, and also two chapters by S. E. Brown on water supply and electric 

 lighting systems for the farm. A section is devoted to threshing machines and 

 the science of threshing. Chapters on the operation of gas and oil engines are as 

 follows : The gasoline farm tractor, fuel consumption of gas engines, alcohol as 

 fuel, kerosene as fuel for traction engines, balancing of engines, piston rings, 

 valves, leaky pistons, the cylinder, the carbureter, modern ignition, vaporizing 

 of fuel, cooling systems, lubrication, horsepower calculations, and gasoline 

 engine troubles. 



The care and repair of rubber belts, R. Moore {Power, 38 {1913), No. 4, 

 pp. 145, 146, figs. 5). — This illustrated article gives instructions for splicing and 

 stitching rubber and canvas belts. The use of rubber belts on too small pulleys 

 is not recommended, since the resulting inside compression and outside tension 

 is likely to separate the plies. It is stated that animal fats and grease should 

 never be used as dressing on rubber belts, but that boiled linseed oil is good, and 

 also equal parts of black lead, red lead, French yellow, litharge, and enough 

 Japan drier to make it dry quickly. 



The construction of creameries, M, Mortensen and J. B, Davidson {Iowa 

 Sta. Bui. 139, pts. 1, pp. 126-146, figs. 11; 2, pis. 21).— Fart 1 of this bulletin 

 deals with the factors determining the success or failure of a local creamery, 

 forms of organization, and data as to the location and construction of cream- 

 eries as regards convenience, sanitation, heating, lighting and ventilation, and 

 materials of construction. Eight typical creameries are described with specifi- 

 cations for their construction and bills of material. Part 2 gives building 

 plans for these creameries. 



Modem silo construction, J. B. Davidson {Iowa Sta. Bui. 14I, pp. 159-229, 

 figs. 63). — This bulletin covers briefly the field of Bulletin 100 of the Iowa 

 Station (E. S. R., 20, p. 6S7) and Piulletin 117 (E. S. R., 23, p. 590) and adds 

 descriptions of several recent developments in silo construction, among which 

 are the wooden hoop silo, pit silo, and the Iowa silo used as a water tower. 

 In the last the silo walls are designed of sufficient strength to support a water 

 tank for the general farm supply. The success of this method is to be reported 

 in a later bulletin. 



RURAL ECONOMICS. 



A normal day's work for various farm operations, H. H. Mowrt {U. S. 

 Dept. Agr. Bui. 3, pp. 44)- — Notes and data based in part on personal observa- 

 tions and in part on replies to a circular of inquiry sent to 25,000 selected 

 farmers as to the average or normal day's work for various farm operations 

 are presented. Tables are given illustrating a normal day's work in using 

 walking, sulky, and gang plows; plowing stubble and sod with a traction 

 engine; using spike-tooth, spring-tooth, and disk harrows, a land roller, a 

 grain drill, a broadcast seeder, knapsack sower, and wheelbarrow sower ; in 

 planting cotton, corn, sweet potatoes, Irish potatoes, cabbage, and tomatoes; 

 cutting potatoes for seed and covering same after planting; making rows for 

 planting; hauling and spreading manure with a spreader and by hand and 



