1920] RURAL ENGINEERING. 481 



ding. In land clearing work in 1917, 30 per cent dynamite proved more effective 

 than 20 per cent. 



" The delayed system of clearing on tract 3 was superior to green clearing 

 on tract 1 in three re.spects: (1) There was a saving of one-third or more in 

 cost per acre. (2) There was a certain annual pasture crop harvested by the 

 cattle while the crops from tracts 1 and 2 were low in volume and high in cost 

 of production. (3) The quality of the land was improved by the decaying 

 vegetation and thickening sod, the land more easily plowed, and a better and 

 cheaper seed bed produced." ^ 



Terracing of fields {Univ. Tucvmdn, Ext. Agr. Boh 36 [1910], pp. 1-10, fio>^- 

 5). — Features of land terracing to prevent soil erosion, as practiced in Argen- 

 tina, are discussed. 



Modern road construction, A. T. Byrne {Chicago: Amer. Tech. Soc, 1019, 

 PP- [S] +187+6. figs. 110). — This is a practical treatise on the engineering 

 problems of road building, and includes a compilation of specifications for 

 modern highways and city streets and boulevards. 



The following subjects relating to country roads and boulevards are dealt 

 with : Resistance to movement of vehicles, location of roads, preliminary road 

 construction methods, and maintenance and improvement of roads. 



Modern roads, H. P. Boulnois {London: Edicard Arnold, 1919, pp. YII-\- 

 S02, pis. IS, figs. 6). — This book is intended for a comprehensive treatise on the 

 subject, covering modern improvements and methods as far as possible, with 

 particular reference to British practice. No cost data are given. 



The following chapters are included : Traffic, water-bound macadamized roads, 

 tar treatment of road surfaces, bituminous roads, bituminous carpets, waves 

 and corrugations, paved streets, concrete roads, and slippery streets. Two ap- 

 pendixes are also included, namely, conference of road users on trafiic regula- 

 tions and Royal Automobile Club — trafllc rules. 



County highway data (Pub. Works, ^8 {1920), No. 12, pp. 276-287) .—Data. 

 obtained by questionnaire from county engineers and officials representing be- 

 tween .300 and 400 counties in the various States are reported, showing county 

 highway work done during 1919 and practice as to road shoulders, resurfacing 

 of county highways, and maintenance of water-bound macadam county high- 

 ways. 



Annual report of the highway commissioner to the governor for the 

 term beginning October 1, 1918, and ended June 30, 1919, C. .1. Bennktt 

 {Conn. Highway Commr. Ann. Rpt., 1919, pp. 84+27, pis. 6). — The work and 

 expenditures of the Connecticut State Highway Department for this term are 

 reported. 



[Thirteenth annual report of the Board of County Road Commissioners 

 of Wayne County, Mich., 1918-19], E. N. Hines et al. {Ann. Rpt. Bd. Road 

 Commrs. Wayne Co., Mich., 13 {1919), pp. 93, pi. 1, figs. 8.9).— This report deals 

 with the work and expenditures on road design and construction in Wayne 

 County, Mich., for the year ended September 30, 1919, the striking feature of 

 the work being the notable development In concrete road construction. 



Road problems in the Ozarks, E. G. Harris {Bui. School Mines and 

 Metall., Univ. Missouri, 11 {1919), No. 3, pp. 70, figs. 7). — This is a revision of 

 a bulletin of the same title issued in 1917 (E. S. R,, 37, p. 695) before the au- 

 thorization of State aid for road building. 



It is state<l that in the Ozark region the present bad location of many of the 

 roads constitutes the chief reason why improvement is impossible, or po.ssible 

 only at great and continuous expense. " In the Ozarks, outside the mining 

 districts, no other material than gravel (including "hardpan") should be con- 

 sidered for road surfacing. The order of improvements should be relocation, 



