290 EXPERIMENT STATION RECOED. 



following chapters : Preliminary investigations ; surveying and mapping ; de- 

 sign ; di'ainage; foundations; earth and sand-clay roads; gravel roads; broken 

 stone roads; bituminous materials; dust prevention by the use of palliatives; 

 bituminous surfaces; bituminous gravel and bituminous macadam pavements; 

 bituminous concrete pavements; sheet asphalt and rock asphalt pavements; 

 wood-block pavements; stone-block pavements; brick pavements, concrete pave- 

 ments, miscellaneous roads and pavements; street cleaning and snow removal; 

 car tracks; pipe systems; comparison of roads and pavements; sidewalks, 

 curbs, and gutters; bridges, culverts, and guard rails; and economics, adminis- 

 tration, and legislation. 



Hard roads in Wayne County, Michigan {Engin. Rec, 68 (1913), No. 13, 

 pp. 34O-342, figs. 8). — A more complete description of this work, which has been 

 previously noted (E. S. R., 27, p. 789), is given, including a note on Michigan 

 road laws, data on concrete road specifications, and details of methods of con- 

 struction. 



Asphalt paving cements and road binders, J. W. Howard (Engin. Rec, 

 68 (1913), No. 13, pp. 345-347). — In pointing out the necessary qualities of 

 asphalt paving cement and road binders and describing laboratory methods for 

 determining them, the author claims from his experience that specifications 

 containing tests for gravity, fixed carbon, paraffin, etc., and only parts of the 

 standard and useful tests are directly in favor of certain limited asphalt prod- 

 ucts and exclude others which may be as good or better. He advocates as the 

 basic and essential qualities, which should be specified, the following: Ad- 

 hesiveness, waterproofness, immutability, cohesiveness, ductility, flexibility, 

 malleability, consistency at mean weather temperature, minimum susceptibility 

 to extreme weather temperatures, purity, and freedom from injury by necessary 

 melting heat. 



Puzzolan mixtures tested for Oregon roads, E. H. McAlister (Cement Era, 

 11 (1913), No. 10, pp. 66, 68).— Tests of various blends of Portland cement and 

 Oregon puzzolans made by the author in an attempt to reduce the cost of con- 

 crete roads in that State indicate that a commercial product of excellent quality 

 may be produced if puzzolanic material is reground with cement 1 : 2 by weight. 

 Comparative cost data show a great saving in favor of puzzolanic mixtures if 

 used on a large scale. 



Road rollers in the ITetherlands, L. C. Steffelaae et al. (Internat. Assoc. 

 Road Cong., III. Cong. [Lo7i(lon], 1913, [Pul).'] 73, pp. 25, figs. 10).— This 

 pamphlet deals with road rollers and road rolling in the Netherlands, giving 

 descriptions of a few modern horse-drawn road rollers and their accessories. 

 These are followed by a discussion of the differences in first cost and cost of 

 maintenance between roads which are rolled and roads not rolled, including 

 tables of cost data from the use of horse and steam engine drawn rollers. 



The advantages claimed for a modern horse-drawn roller owned by a depart- 

 ment are as follows : It can be used in places and under conditions impossible 

 for an engine-drawn roller, is always available at favorable periods, can be 

 profitably used on road improvements of minor importance and on continuous 

 maintenance of roads, and the purchase price is comparatively small. The 

 principal disadvantages are that the road surface is injured by the horses' hoofs, 

 the work is slower than with a traction engine, and good horses are not always 

 available at a reasonable price. 



Tests on small gasoline engines, F. M. and E. A. White (Poioer, 38 (1913), 

 No. 9, pp. 299-301, figs. 5). — Tests were made to determine the fuel consump- 

 tion, in pounds per horsepower hour for varying loads, of 12 small farm tuternal 

 combustion engines using gasoline as fuel. Three general classes of 4 engines 

 each were made, ranging in power from 3 to 4^, 5 to 7, and 8 to 10 h. p. and 



