RUEAL ENGINEEEING. 289 



" The cost of clearing the better grade of wliite-pine logged-off land will 

 average $10 per acre for disposing of the brush and $25 to $30 per acre for 

 dlsix)sing of the stumps. Some green hardwood lands and unburned swamp 

 lands will cost as much as $100 per acre. Some of the poorer jack-pine lands 

 can be cleared for $5 per acre or less. The cost of disposing of the stumps 

 after pulling practically equals the cost of pulling. A tripod or a boom piler 

 is recommended to facilitate piling and burning." 



It is concluded that the settler with little capital and no exi>erience will 

 meet with serious difficulties in attempting to make a farm out of a tract of 

 logged-off land, and it is recommended that " in all localities where land com- 

 panies are selling lands to settlers, no tract of land be sold unless it contains 

 at least 10 acres of laud cleared ready for the plow." 



A manual of the law of roads and highways in the State of Kansas, W. R. 

 Arthur (Topcka, Kans., J913, J3. cd., pp. 126). — Thi.s handbook includes the 

 laws relating to roads and highways passed by the legislature of the State up 

 to and including the session of 1913, and is intended as a text-book and com- 

 pilation of the duties and powers of highway officials. 



HistoiT of road legislation in Iowa, J. E. Bbindley (Iowa City, Iowa, 1912, 

 pp. XIII-\-^22). — This volume deals with road legislation in Iowa from the 

 year 1838. 



Bibliography of road-making and roads in the United Kingdom, Dorothy 

 Ballen {London, 1914, pp. XVIII-\-281). — The contents of this bibliography are 

 classified under the general headings of (1) history and description, (2) ad- 

 ministration, (3) engineering, and (4) traffic. 



An investigation of sand-clay mixtures for road surfacing, J. C. Koch 

 (Proc. Amer. Soc. Civ. Engin., J,0 {191.',), Xo. 2, pp. 269-296, figs. 9; ais. in 

 Engin. and Contract., 41 (1914), No. 11, pp. 321-324, fig. i).— The author pre- 

 sents the results of two years' studies in both field and laboratory of sand-clay 

 mixtures for road surfaces and describes an approximate field method for the 

 examination of sand-clay mixtures and methods of construction with natural 

 and artificial mixtures. 



The conclusions from the laboratory tests are as follows : 



" The content of sand smaller than No. GO is of little value in the mixture, 

 that smaller than Xo. 100, except in very small quantities, is detrimental. The 

 greater the proportion of coarse to fine sand the harder and more durable will 

 the road surface be. For the best possible results with sand-clay mixtures, 

 the sand smaller than No. 10 and larger than No. 60 should not be less than 45 

 I)er cent nor more than 60 per cent, by dry weight, of the entire sample. In 

 addition, the sand smaller than No. 10 and larger than No. 60 should be com- 

 ]iosed of about equal parts of Nos. 20, 40, and 60. The total sand content should 

 in no case exceed 70 per cent by weight of the total sample. 



" Test cylinders of the sand-clay mixture, 1 in. in diameter and 3 in. long, 

 should, when thoroughly dried in air bath at 100° C. take at least 2 minutes, 

 when immersed in water at 21°, to crumble down to the natural slope of the 

 material, and preferably should take 6 minutes. If the cylinder fails in this 

 test, it should be regarded with suspicion. If the sand analysis is poor and the 

 cylinder test is also poor, the material is not worth using." 



Similarly, test cylinders made from the clay removed from the sample 

 should take at least 2 minutes to crumble. If the material fails in this test but 

 passes that of the preceding paragraph it may be used, but indicates a poor 

 quality of binder. 



Standards of concrete road construction (Engin. Rec, 69 (1914), No. 8, 

 pp. 214-216). — A r^sumg of committee reports at the National Conference on 



