BUBAL ENGINEEBING. 385 



Street pavements and paving materials, G. W. Tillson (New York and 

 London, 1912, 2. cd., pp. XV 1+651, pi. 1, figs. 97).— This book contains chapters 

 on the history and development of pavements ; stone ; asphalt ; brick-clays and 

 the manufacture of paving-brick; cement, cement mortar, and concrete; the 

 theory of pavements ; cobble and stone-block, asphalt, brick, wood, broken-stone, 

 and concrete pavements; plans and specifications; the construction of street-car 

 tracks in paved streets; width of streets and roadways, curbs, sidewalks, etc.; 

 asphalt plants : and the protection of pavements. 



Fourth American Good Roads Congress and tenth annual convention of 

 the American Road Builders' Association {Good Roads, n. ser., 7 (1914), 

 Xos. 1, pp. 3-59; 6, pp. 91-126). — The.se proceedings include a number of special 

 papers which deal with different phases of the design, construction, mainte- 

 nance, and repair of different types of roads and with road administration. 



Road laws of the State of Washington (Olympia, Wash., 1913, pp. 263). — 

 These laws relate to road construction, financing, and administration. 



Practical handbook of gas, oil, and steam engines, J. B. Rathbun ( Chicago. 

 1913, pp. 370; rev. in ScL Amer., 110 (1914), No. 10, p. 212).— This book deals in 

 condensed form with the construction, opei'ation, and repair of all kinds of 

 engines, with the various parts in detail, and with the different kinds of fuel. 



The construction and design of internal combustion motors, H. Gl'ldner 

 (Das Entwerfen und Bcrcchnen der Verirennuitgskraftniaschinen mid Kraftgas- 

 Anlagen. Berlin, 1914, 3. ed. rev., pp. XX+SOO, figs. 1282; rev. in Engin. News, 

 71 (1914), No. 12, p. 648). — This book is meant primarily for the designer of 

 internal combustion engines. It contains many detailed drawings of parts, 

 assembled drawings of complete machines, and tables of performance, as well 

 as data on the fundamental theory that is necessary in design. 



A fuel-saving device for oil engines, E. R. Adlington (Gas Engine, 16 

 (1914), No. 2, pp. 84-86, figs. 3). — Tests of a recarbureting device for remixing 

 and increasing the uniformity of the gasoline and air mixture are reported. 

 The device consisted of a rapidly revolving fan placed in the intake pipe. 



Curves of results obtained with and without the recarbureter showing brake 

 horsepower platted against pounds of gasoline per brake horsepower hour, 

 percentage of thermal efiiciency, and revolutions per minute all point more or 

 less favorably toward the use of the recarbureting device. It is concluded 

 that the points in favor of such a device are (1) reduction in gasoline con- 

 sumption, (2) increased engine capacity, (3) higher speed at maximum loads, 

 and (4) greater thermal efficiency. 



Fuel consumption and effective utilization of energy in small power 

 motors, Chaebonnier (Maschinen Ztg., 12 (1914), Nos. 1, pp. .^-8; 2, pp. 

 19-22). — The author gives tables of data comparing the fuel consumption, 

 effective utilization of energy, and cost of operation per effective horsepower 

 hour for portable saturated and superheated steam engines, gas and crude oil 

 engines, and electric motors of from 5 to 20 horsepower, operating at \. h, %, 

 and full load. 



The electric motors showed the least increase in fuel consumption per ef- 

 fective horsepower hour with decrease from full to l load, followed in order by 

 the superheated and saturated steam engines, and the crude oil and gas en- 

 gines. The crude oil engines showed the highest effective utilization of heat 

 units in fuel per effective horsepower hour from full to i load, followed in order 

 by the gas engines, the electric motors, and the superheated and saturated sjeam 

 engines. 



Using German prices for coal, gasoline, crude oil, and electricity per 10,000 

 heat units, it is shown that on the basis of the results obtained for fuel con- 

 sumption and energy utilization the crude oil engine is the most economical 



