1917] 



RURAL ENGINEERING. 



Crushing tests of cemented brick piers. 



287 



" The results of tliis investigation unquestionably determine that hydrated 

 lime has a greater value in brick masonry than it is generally given credit for 

 having." "Assuming the market price of Portland cement and hydrated lime 

 to be the same, pound for pound, specifications calling for mortar to be com- 

 posed of 50 lbs. of Portland cement, 20 lbs. of hydrated lime, and 300 lbs. of 

 sand (approximately 0.5 cu. ft. Portland cement, 0.5 cu. ft. hydrated lime, and 

 3 cu. ft. of sand) will not only give a much higher structural value, but will 

 also make a saving of 30 cts. on every dollar spent for the cementing mixture in 

 brick mortars." 



Handbook of practical smithing and forging, T. Moore {Neio York: Spon 

 d Chamberlain, 1914, PP- [T'/]+248, figs. JfOl). — This is a practical treatise on 

 the arts of smithing and forging, in which the author first deals with forges, 

 hearths, hammers, forging machines, presses, iron and steel, and testing, and 

 then devotes considerable space to a description and discussion of practice in 

 general forging and smithing, including a summary and explanation of technical 

 terms, expressions, and phrases. Tables of handy data are appended. 



Gas-engine principles, R. B. Whitman (New York and London: D. Appleton 

 & Co., 1915, pp. XV-\-24S, figs. 74). — This is a semitechnical treatise on the 

 handling, care and maintenance of small stationary gas engines and contains 

 the following chapters : Gas-engine principles ; engine types ; engine parts ; 

 valves and valve mechanism ; carburetion ; ignition and electrical principles ; 

 electric generators ; make-and-break systems ; jump spark ignition system ; lubri- 

 cation and cooling ; power, care, and maintenance ; causes of trouble ; effects of 

 trouble ; and testing for trouble. 



Tractor engines, W. J. McVickee (Gas Engine, lb {1916), No. 7, pp. 333- 

 336). — In considering the requirements necessary to meet the conditions in 

 power farming, it is pointed out that a successful tractor engine must have the 

 following qualifications regardless of its type : 



" It must be so constructed that it can develop its maximum horsepower con- 

 tinuously without self-destruction. The elements of limited overload must be 

 eliminated because it can not be controlled. It must start and operate without 

 undue loss of time and must do a season's work with ordinary care and without 

 the services of an expert. ... It must develop its rated power economically, 

 and operate .successfully with the kinds of fuel common in the locality where 

 it is to be used." 



A novel cooler for internal combustion engines (Sci. Amer. Svp., 82 {1916), 

 No. 2123, p. 165, figs. 2). — A cooler designed for the efficient and rapid trans- 



