RURAL ENGINEERING. 



281 



the waters of 207 were good, of 26 bad, aud of 38 doubtful. Of the springs ex- 

 amined the waters of 26 were good, of 5 bad, and of 11 doubtful. Of the cis- 

 terns examined the waters of 22 were good, of 6 bad, and of 9 doubtful. 



Water analyses from the laboratory of the United States Geological 

 Survey, F. W. Ci^vrke (U. 8. Geol. Survey, Water-Siipply Paper 364 U914), 

 pp. 40)- — ^This paper contains 203 water analyses, most of which have been 

 published elsewhere. 



The farm water supply, H. G. Ramsoweb (Farm Engin., 2 {1914), No. 3, 

 pp. 50, 51, figs. 4)- — In discussing power for pumping farm water the author 

 is of the opinion that for the average farm the windmill will, in the long run, 

 afford a cheai^er and more satisfactory pumping power than the gas engine. 

 He prefers the steel wheel and tower and states that a back-geared mill should 

 be used in windy sections and a direct-geared mill in less windy sections. A 

 12 ft. w'heel is considered to be the largest practical size to use. 



Results of tests on stationary gas engines (Oas Engine, 16 (1914), No. 9, 

 pp. 548-551). — The results of tests of 7 stationary farm gas engines are 

 reported in tabular form, giving in addition complete data of dimensions of 

 parts, methods of governing, ignition, oiling, cooling, etc. Five engines were 

 rested on gasoline, 1 on kerosene, and 1, a 2-cycle engine, on distillate. 



Out of a possible total of 500 points rated according to economy,, general 

 operation, design, and construction, the kerosene engine, rated at 6 horsepower, 

 made the highest score of 451.5 points. The following scores were made by 

 the gasoline engines: 7 horsepower, 411.9; 5 horsepower, 406.5; 6 horsepower, 

 385.8 ; 4 horsepower, 383.9 ; and 8 horsepower, 332.5. 



The more Important test results are summarized in the following table : 



Summary of gas engine tests. 



The theory of the plow mold board, R. Bernstein (Kiihn Arch., 5 (1914), 

 pp. 169-189, figs. 11). — The author di-scusses mathematically and graphically 

 the development of the plow mold board, dealing mainly with the action in soil 

 of both the curved and the so-called cylindrical mold board. 



Results of motor plow demonstrations and tests, B. Martiny (Kiihn Arch., 

 5 (1914), PP- 111-126). — The author reviews the results of several motor 

 plowing contests, held in Germany, for the purpose of showing how the oper- 

 ating characteristics of several of the better-known motor plow systems are 

 affected by the conditions of a motor plow demonstration. The main points con- 

 sidered are steering, uniformity and completeness of the plowing, soil com- 



