386 EXPERIMENT STATION RECORD. [Vol. 37 



Laws of Iowa relating to roads and highways passed by the thirty-sixth 

 general assembly, 1915, Lola S. Elxjott (Des Moines, loxca: State, 1915, pp. 

 28). — The text of the laws is given. 



Cost of engineering an extensive county road system, W. C. Davidson 

 (Eiujin. Rec, 75 (1917), No. IS. pp. 498, ^99).— This article is a description of 

 the items chargeu to engineering in the cost of construction of a road system in 

 Texas consisting of 5 miles of concrete. 63 miles of water-bound macadam, and 

 110 miles of gravel construction and entailing the building of 488 bridges and 

 culverts. The total cost amounted to $1,075,000, of which 4..58 per cent was for 

 engineering. 



The results of physical tests of road building rock in 1916, including all 

 compression tests, P. Hubb.vrd and F. H. Jackson, jr. (U. S. Dept. Agr. Bui. 

 537 (1917), pp. 23, fig. i).— This bulletin supplements Bulletin 370 ( E. S. R., 35, 

 p. 685) and reports the results of the more common physical test.s, including 

 crushing, of 396 samples of road-building rock examined by the Office of 

 Public Roads and Rural Engineering during 1916. as well as a complete record 

 of all crushing-strength tests made by the Office up to January 1, 1917. 



Material specifications (Ohio Highway Dept., Material Specifica. 5 (1916), 

 pp. 80. figs. 9). — Specifications for Portland Cement. pa\ing block, stone and 

 slag, gravel and sand, nonbituminous binders, bituminous materials, creosoted 

 timber, oils and paints, steel and iron, and pipe, as prepare«l by th^ Ohio high- 

 way department, are presente<l, together with outlines of methods of testing. 



United States Government specification for Portland cement ( U. S. Dept. 

 Com., Bur. Standards Circ. 33, 3. ed. (1917). pp. J,3, ftg.<<. ;0).— This siK-iflcntlon 

 is the result of several years' work of a Joint conference representing the 

 U. S. Government, the American Society of Civil Engineers, and the American 

 Society for Testing Materials. It was adopte<l by the U. S. Government and 

 by the American Society for Testing Materials, to become effective January 

 1, 1917. 



Creosoting Douglas fir bridge stringers and ties without loss in strength, 

 O. P. M. Goss (Seattle, Wash.: Assoc. Creosot. Cos. of the Pacific Coaxt, 1916, 

 pp. 27, figs. 11). — This circular briefly describes Douglas fir as a structural 

 timber, and discusses particularly a method of effectively creosoting structural 

 forms without loss in strength. This consists essentially of boibng tbe timber 

 in cre.sote oil under a vacuum of from 24 to 27 In. 



Results of strength tests on bridge stringers and ties and of spike-pulling 

 tests are also reported, giving information which In general should be of 

 interest to engineers responsible for the efficient use of structural timl)er. 



Timber framing, H. D. Dewell (West. Engin., 7 (1916), Nos. 6. pp. 209-216, 

 figs. 2; 7. pp. 251-256. figs. 10; 8, pp. 289-298. figs. 11: 9. pp. S.t9-3i6. figs. 9; 

 10] pp. 385-393. figs. 13; 11, pp. 416-^2^, figs. 11; 12. pp. 4.%5-461, figs. 11; 8 

 (1917). Nos. 1, pp. 9-17. figs. 7; 2, pp. 52-56. figs. 7; 4. pp. 132-1 J,2. figs. 7).— 

 Tills is a series of ten articles on the design and construction of timber-frame 

 Btructures. 



I'art 1 summarizes specifications for gradinc timber In use on tbe Pacific 

 coast and discusses working-unit stre.sses and ultimate strengths of main mem- 

 bers. Part 2 deals with washers and pin-connected joints and gives experi- 

 mental data regarding their strength. Part 3 di.^cusses the design of timber 

 connections using nails, screws, lag screws, and bolts, and summarizes related 

 experimental data. Part 4 deals with end Joints of timber trusses and gives 

 detailed computations and drawings for eight different types of Joint. Part 5 

 discusses the complete design of intermediate joints in trusses, of tension 

 ■plices. and of compression splices. Part 6 dlcusses compression chortls and 



