690 EXPERIMENT STATION EECOED. 



Tests of motor plows, B. Martiny (Mitt. Prilf. Stat. Landw. Masch. u. 

 Gerate, Halle, 1912, No. 163, pp. .'/6, fig. I).— The methods and results of tests 

 are given of 3 types of motor ground breaker, namely, the ordinary motor plow, 

 the motor plane plow, and the combination motor and rotary gronnd breaker. 

 A general discussion is given of the methods of motor operation and draft 

 employed by different makes, the power required, and the results obtained under 

 varying conditions of soil and weather. 



Agricultural motor trials in Algeria (Impl. and Much. Rev., 38 (1912), No. 

 ^49, pp. 651-653, figs. 5). — This article compares the results of several sets of 

 plowing trials on motor tractors taken at different times of the year under 

 varying conditions of soil and atmosphere. The results show the fallacy of 

 judging the machines and overestimating the results as obtained from the 

 tests of only 2 or 3 days' duration, as has been the custom, and indicate that a 

 comparison is only possible when the machines are employed for various con- 

 ditions of work over the gi-eater part of the year. 



Gasoline as a fuel for motor use (Farm Machinery, 1912, Nos. 1087, pp. 32, 

 S-i; 1088, pp. 30, 32; 1089, p. i6).— This is a scientific study of the different 

 grades of gasoline, indicating that gravity is no criterion as to the quality, as 

 is commonly accepted, but that the quality of a gasoline is expressed by its 

 initial, intermediate, and maximum boiling points. 



The ordinary gasoline has several boiling points, portions of it vaporizing 

 at low temperatures and others at from low to high temperatures. For easy 

 starting, a gasoline engine requires a gasoline with low initial boiling points, 

 but as it warms up it requires higher and higher boiling points in the gasoline 

 to satisfy the increasing demand for power, consequently gasoline to produce 

 the best results in a motor must have low initial boiling points, gradually rising 

 to high boiling points. A high-gravity gasoline is no better than a low-gravity 

 gasoline if they have the same boiling points. 



Steam or electricity in dairy work (Mollc. Ztg. [Hildesheim], 26 (1912), 

 No. 58, pp. 1087, 1088; Landic. Masch. u. Gerate, 12 (1912), No. 17, pp. [1-7].— 

 A comparison of the uses of steam and electricity in an average small dairy, 

 giving the daily and yearly cost figures for the operation of a 10-horsepower 

 steam engine and an 8-horsepower electric motor. It indicates that electric 

 power must cost as low 2J cts. per kilowatt hour in order to give the economy 

 of steam when both machinery driving and milk and water heating are taken 

 into consideration. 



Library of Agriculture — Country life conveniences and enjoyments, edited 

 by H. ]\r. Skinner and A. L. McCredie (Chicago, 1912, vol. 8, pp. 502, figs. 61).— 

 This book is made up chiefly of reprints of Farmers' Bulletins of the U. S. 

 Department of Agriculture. 



RURAL ECONOMICS. 



[Questions relating to rural economics], H. L. Rl^ssell et al. (Bui. Univ. 

 Wis., 1912, No. 509, pp. 125, figs. 2-)). — This bulletin presents the papers given 

 at the Second 'Wisconsin Country Life Conference conducted under the auspices 

 of the College of Agriculture of the University of Wisconsin. Among those 

 relating directly to the economic side of country life the following are noted : 

 Value of Cooperation Among Farmers, by G. F. Comings: Efficient Use of 

 Labor on the Farm, by H. C. Taylor; Hired Labor on the Farm and in the 

 Home, by W. L. Nelson, and The Decline in Rural Population, by B. H. Hibbard. 



Financing the farm, M. T. Herbick (Addresses Ann. Meeting Ohio Bd. Agr., 

 1912, pp. 28-Ji3). — An address delivered at the annual meeting of the Ohio State 

 Board of Agriculture, Columbus, Ohio, January 10, 11, 1912. in which the author 

 illustrates the economic significance of scientific methods in farming by statistics 



