188 EXPEEIMENT STATION EECOKD. 



this reason it is tliought that all such tests should be conducted before thp 

 judges only and that the general public should be excluded. 



Motor cultivation by tractors or rotating- cultivators, K. de Meyenbukg 

 iX. Cong. Inteniat. Agr. Gand, 1913, Sect. 4, Question 1, pp. 10). — This is a 

 comparative discussion of tractor-drawn plows and motor scarifiers or rotating 

 cultivators in which the author favors the latter type. 



Basis for the testing of mechanical cultivating' implements, P. Gioedako 

 (X. Cong. Internat. Agr. Gand. 1913, Sect. 4, Question 1, pp. 9, pis. 2, figs. 5). — 

 In the testing of soil cultivating machinery the importance of first determining 

 the tenacity or cohesive properties of a soil and the frictional resistance of the 

 soil particles to a metal wedge is pointed out, and a device for determining these 

 physical characteristics of the soil is described. 



Motor-drawn and motor-operated grain binders, M. Ringelmann (Jour.. 

 Agr. Prat., n. ser., 78 {19 Ui), No. 2, pp. 5-'t-57, figs. 3). — The author reviews the 

 results of dynamometer tests of grain binders and shows by curves of data the 

 tractive power required for drawing the binder and for operating the mecha- 

 nism. He concludes that the average binder in average wheat or oats with a 

 1.5 meter sickle and a speed of about 1.2 meters per second will require a 

 4-horsepower motor for operating the mechanism alone, and a 14 to 15-horsepower 

 motor for both locomotion and operating the mechanism, due allowance being 

 made for possible grades and obstructions. 



Experiments with, an electrically-driven thrashing machine, G. Coxjpan 

 (Z. Cong. Internat. Agr. Gand. 1913, Sect. 4, Question 1, pp. 14-I6). — These 

 experiments show that the hulling, cleaning, etc., of grain require only a small 

 part of the total power utilized by the thrasher, the greater portion being con- 

 sumed by the friction of the mechanism. 



Operating characteristics of centrifugal pumps, A. B. SIorbison. je. (Power, 

 39 (1914), No. 5, pp. 166-168, figs. 2). — Centrifugal pumps are discussed from 

 the standpoint of operation, taking up particularly the effect of speed and head 

 on the capacity, and the influence of throttling v. some form of speed control 

 on the efficiency. 



The author is of the opinion that wherever feasible some form of speed con- 

 tBol should be used. " It is almost impossible to determine accurately before- 

 hand the head against which the pump will work, and with a fixed speed any 

 change in piping or operating conditions may make a great difference in the 

 amount discharged and in the power required." Curves and data are included. 



The cost of pasteurizing milk and cream, J. T. Bowen (V. 8. Dept. Agr. 

 Bui. 85 (1914), pp. 12, fig. 1). — This bulletin deals with the cost of pasteuriza- 

 tion by the " holder " and " flash " processes from an engineering point of view, 

 and contains information for proprietors of creameries and milk plants and for 

 designers and manufacturers, of pasteurizing apparatus. Tests are reported 

 on the milk pasteurizing equipment of five city milk plants and on the cream 

 pasteurizing equipment of four creameries, the latter covering both the flash 

 and holder processes. 



In the milk pasteurization test, live steam was used taken direct from the 

 boiler, but reduced in pressure to from 3 to 5 lbs. while the cream pasteuriza- 

 tion was accomplished by using (1) live steam direct from the boiler, (2) 

 exhaust steam from the engine or from steam-driven pumps, and (3) hot water 

 heated by the exhaust steam from the steam-driven auxiliaries. 



Data of the tests relative to heating, cooling, heat balance, temperature bal- 

 ance, and costs are given in tabular form. The average cost of pasteurizing 

 1 gal. of milk was found to be 0.313 cts., and the average cost of pasteurizing 

 1 gal, of cream, 0.634 cts. 



