188 EXPERIMENT STATION RECORD. [Vol. 36 



A comparison of the effect of the road improvement upon country schools 

 showed that before the roads were improved the average school attendance 

 was 66 pupils of each 100 enrolled, as compared with 76 after the roads were 

 improved, showing that the good roads have been materially responsible for the 

 education of 10 children out of each hundred. 



Bituminous m.acadam and bituminous concrete pavements, A. H. Blan- 

 CHAED {Municipal Jour., J^l {1916), JSlo. l-i, pp. Jt05-^11, figs. 9). — This article 

 summarizes the more recent opinions of authorities on the materials and 

 methods requisite for the most successful construction and maintenance. 



In monolithic pavements in Vermilion County, Illinois, brick are laid 

 directly on concrete base, H. H. Edwards {Engin. Rec, 74 {1916), No. 14, PP- 

 jfOO-402, figs. 7). — This article summarizes experience in which the thin layer 

 of dry sand and cement was discarded. The brick were grouted immediately 

 after rolling. 



Distribution of traffic on a rectangular system of roads analyzed, E. W. 

 James {Engin. Rec, 74 {1916), No. 15, pp. 439-Ul, figs. 2).— Tabular data are 

 reported which show the relative travel on various types of roads where the 

 development is uniform throughout a township and where it is unequal and 

 more in accordance with ordinary experience. It is pointed out that from 80 

 to 85 per cent of all traffic in any large area is carried by 15 or 20 per cent of 

 the roads and that expenditures should be governed accordingly. 



Progress i*eports of experiments in dust prevention and road preservation, 

 1915 {U. S. Dcpt. Agr. Bnl. 407 {1916), pp. 71). — ^New experiments begun by 

 the Office of Public Roads and Rural Engineering during the year 1915 are de- 

 scribed. These included experiments on bituminous macadam (penetration and 

 mixing methods) and bituminous gravel concrete on Mount Vernon Avenue 

 road, Alexandria County, Va. ; bituminous surface treatment on Falls Road, 

 Montgomery County, Md. ; penetration macadam on Bradley Lane, Montgomery 

 County, Md. ; bituminous concrete at Washington, D. C. ; oil-asphalt-coralline 

 rock at Buena Vista, Fla, ; oil-asphalt-sand at Jupiter, Palm Beach County, 

 Fla. ; bituminous-sand, mixing methods at West Palm Beach, Fla.; and sand- 

 asphalt at Ocala, Fla. 



Supplementary reports on experiments previously reported (E. S. R., 33, p. 

 686) are included on oils, tar preparation, calcium chlorid-coralline rock at 

 Lemon City, Fla. ; oil, tar, oil-asphalt-coralline rock at AYest Palm Beach, Fla. ; 

 oil-coralline rock at Miami, Fla. ; bituminous surface treatment on Rockville 

 Pike, Montgomery County, Md. ; tar preparation and oil-surface treatment at 

 Washington, D. C. ; bituminous concrete, cement concrete, oil-cement concrete, 

 vitrifiied brick, bituminous surface treatment on concrete and bituminous con- 

 struction and surface treatment at Chevy Chase, Md. ; oil-cement concrete, 

 oil asphalt, tar and fluxed native asphalt at Jamaica, N. Y. ; oil-asphalt-gravel 

 at Ames, Iowa; tar and oil preparations at Knoxville, Tenn., 1910; slag, lime, 

 waste sulphite liquor and tar at Youngstown, Ohio; sand-clay at Dodge City, 

 Garden City, Bucklin, and Ford, Kans. ; and Kentucky rock asphalt at Bowling 

 Green, Ky. 



Boad dust preventives: References to books and magazine articles {Pitts- 

 burgh, Pa.: Carnegie Library, 1916, pp. 3.9).— A list of 361 references to books 

 and magazine articles bearing on the subject is given. 



Concrete construction for rural communities, R. A. Seaton (Neio York and 

 London: Mvaraw-HiU Book Co., 1916, pp. XI +223, pi. 1, figs. 96).— This is a 

 semitechnical treatise on the essential features of concrete construction on 

 farms and in rural communities. It is divided into five parts. Part 1, Mate- 

 rials, deals with cements and limes, cement specifications and tests, and aggre- 



