EUKAL ENGINEERING. 387 



Agricultural machines, K. Walther (Die landwirtschaftUchen Maschinen. 

 Leipsic, 1910, vol. 2, pp. 120, figs. G-i; 1911, vol. 5, pp. 156, pi. 1, figs. 91).— 

 These are the second and third volumes of this series, the first having been 

 previously noted (E. S. R., 21, p. 186). 



They treat of harvesting machinery and machinery for the cleaning, storing, 

 preparing for use, etc., of the different crops after harvesting, describing the 

 construction and methods of operation of mowing machines, binders, hay ralies, 

 tedders and loaders, potato and turnip diggers, threshing machines, grain 

 cleaning and sorting machines, hay presses, and feed preparing machines. 

 There is also included a chapter on agricultural motors. 



Agricultural machinery, G. Coupan (Bui. Soc. Agr. France, 1912, Apr. 13, 

 pp. -'/0'i-.'il3; May 1, pp. .'(57-461, figs. 7). — Several agricultural machines are 

 briefly described, among which are ground and crop cultivators, tractors, drills, 

 and harvesters. The mechanical theories for some types of potato diggers and 

 drills are illustrated and explained. 



The efficiency of the farm tractor, R. Beresford (loioa Agr., 12 (1912), No. 

 7, pp. 12-1 Ji, figs. 2). — The author computes the cost of plowing by gas tractor 

 at 40 cts. per acre, and by horses at 60 cts. per acre. He calls attention to a 

 number of cases where gas tractors have proved efficient and profitable on 

 farms. 



[A 24-hour test of a tractor] (Impl. and Mach. Rev., 57 (1912), No. Wh PP- 

 1513, 1574). — ^"^ 24-hour test was made of a 50-brake horsepower, 4-cylinder, 

 S-speed motor in plowing and pressing, the implements employed l)eing a 4-fur- 

 row plow and a o6-in. 5-wheel land presser. 



The results show that 20 acres 89 sq. yds. of land were plowed and pressed 

 in 24 hours. The amount of gasoline used was 69^ gal., or about 3i gal. per 

 acre, and the amount of lubricating oil used If pt. per acre. The opinion is 

 presented that a light, powerful, speedy tractor, drawing a comparatively small 

 plow, is more efficient than a slower, heavier machine, pulling a greater number 

 of plows. 



An effective stumping machine (Queensland Agr. Jour., 28 (1912), No. Jf, 

 pp. 290-292, figs. 2). — A stump puller and its method of operation are described. 

 It consists essentially of an iron and wood frame supporting a wooden drum or 

 roller which revolves by lever action and operates a block and tackle and steel 

 cable pulling system. An illustration is given showing the working parts iu 

 detail. 



[Trials of corn and seed drills] (Impl. and Mach. Rev., 38 (1912), No. 4^5, 

 pp. 70-74, figs. 9). — The method and results of tests on several makes of corn 

 and seed drills for accuracy, even distribution of seed, simplicity, and general 

 efficiency are given with the constructive details and the price of each machine. 



Milking with machines (Wiener Landw. Ztg., 62 (1912), No. 27, pp. 339, 

 SSfO). — ^A discussion is given of the relative merits of suction and pressure 

 milking machines, the advantages of light weight, simplicity, ease of adjust- 

 ment, and speed in milking being conceded to the suction machines, and the 

 advantages of steady and systematic action, easy control, ready cleaning and 

 airing, complete milking, and easiness on the cow to the pressure machines. 

 Several different makes of these two machines are described. 



Farm power, L. W. Chase (Deseret Farmer, 7 (1912), Ifo. 28, p. 651, fig. 1). — 

 Results of tests conducted at the Urdversity of Nebraska on gasoline engines, 

 showing the gasoline consumed in different kinds of farm work, are reported. 



From these tests and other computations it is estimated that 1 gal. of gasoline 

 in a 3-horsepower engine will complete any one of the following operations: 



56022°— No. 4—12 7 



