RURAL ENGINEERING. 785 



absorption. ... No coating compound can be successful that will disintegrate 

 under the influence of the weather. . . . Although linoxyn Is readily saponl- 

 fiable in the cold, there is not, under ordinary conditions, enough lime carried 

 out by tlie small amount of water that may penetrate a paint film In good condi- 

 tion, to cause disintegration of the film. . . . The absence of stains on the 

 green test paint film in the ca.ses of some of the panels, the coats of which 

 showed disintegration at the time of application of the green, would indicate 

 that the lime at the surface of the panels hud become pretty well carbonated 

 within the first year. Any stucco exposed to the weather for a year's time can 

 be coated .satisfactorily with a good outside paint. A successful concrete coating 

 material should be compounded on the same basis as is used for a satisfactory 

 outside paint for wood, with only such adjustments in composition as tend to 

 make it more nearly impervious, and these must not be made at the expense of 

 the elasticity and general durability of the film." 



An analysis of worn out and ravelled macadam surfaces with, suggestions 

 as to treatment, E. A. Stevens (Engin. and Contract., 42 (1914), No. 1, pp. H, 

 15). — The author points out that ravelling of macadam surfaces is due to (1) im- 

 proper construction, (2) overload, or (3) neglect. Reconstruction of defective 

 sections is the remedy suggested for the first cause of raveling, resurfacing with 

 a better type of surface for the second, and repair of the old surface for the 

 third. It is pointed out in this connection that a road structure may be so 

 maintained as to increase its carrying capacity greatly, thus making the prob- 

 lem largely one of economics and administration. 



The prevention of the subcrust movement in roads, E. S. Sinnott {Sur- 

 veyor, 46 (1914), No. 1112, pp. 9-11, figs. 7). — A means for preventing the lateral 

 and longitudinal movement of material forming the subcrust of highways under 

 heavy traffic is described and illustrated. The essential feature is that longi- 

 tudinal and cross members are placed at a suitable depth below the surface 

 to preclude any movement of the subcrust and at the same time to provide a 

 means of constructing an impervious arch of tarred macadam to carry the 

 traffic. It is thought best to construct the frames of reinforced concrete. 



Carburation in theory and practice, R. W. A. Bbewer {New York, 1913, pp. 

 VIII +253, figs. 70). — It is the puriwse of this book to provide in convenient 

 form information upon the properties of various fuels, what treatment these 

 fuels require for use in an engine, and what has been done in the past in 

 order to obtain the necessary data upon which to base the theory. Chapter 1 

 gives a general outline of the subject, explaining terms used, describing early 

 carburetting devices, and discussing the general pi-inciples of carburation and 

 modern requirements. The succeeding chapters deal with the following sub- 

 jects: Vaporization and evaporation; limits of combustion — air and heat re- 

 quired ; inlet pipes and inertia ; the flow of fuel through small orifices ; the 

 annulus; Brewer's fuel orifice; special jets; moving parts; float chambers; 

 petrol substitutes; exhaust gas analyses ; rri carburettors. The closing chap- 

 ters consist of descriptions of some of the best-known carburettors with 

 criticisms thereon. Appendixes give tabular data as to equivalents, conversion 

 from degrees Baumg to specific gravity, and properties of gases. 



Simple water testing, P. Edelman {Chicago, 1913, pp. 50, figs. 20). — This 

 pamphlet outlines quick, cheap, and practical methods of analyzing boiler 

 feed-water, and for regulating the 111 effects of impurities. 



Steam plowing experiments in the Aira estate, Kheri, United Provinces, 

 B, C. BuET {Agr. Jour. India, 9 {1914), No. 1, pp. 1-6, pis. 2). — Plowing experi- 

 ments on heavy grass land with an alluvial soil very sandy in places, using a 

 single-cylinder oil-burning steam tractor of about 25 brake horseiwwer, 

 dragging two sets of 3-disk plows, and cutting furrows 10 in. wide and about 



