1916] RURAL ENGINEERING. 493 



Country roads board [Victoria], first annual report (Ann. Rpt. Country 

 Roads Bd. Victoria, 1 (1914), pp. 94, pis. 7, figs. 88).— This report deals mainly 

 with preliminary work connected with the investigation of highways, the 

 condition of the roads in different districts, and methods of dealiug with roads 

 by the Government and municipalities of Victoria. 



Recent road legislation of Iowa, edited by H. E. Sampson and T. H. Mac- 

 Donald (Iowa State Highway Com. Scrv. Bui., 3 {1915), No. 9, Sup., pp. 104). — 

 The text of the law is given. 



The law of Ohio governing roads and bridges, W. M. Rockel (Cincinnati, 

 Ohio: The W. H. Anderson Co., 1916, pp. -YL+646).— This gives the text of the 

 Ohio laws governing roads and bridges, including the establishment, con- 

 struction, improvement, and repair of roads and bridges by state, county, and 

 township officials ; and the text of the law as to the adjoining landowners and 

 the traveling public. 



Experiments with dynamite, F. Watts (Imp. Dcpt. Agr. West Indies, Rpt. 

 Bot. Sta. [e<c.] Antigua, 1914-15, pp. 29, 30). — Experiments on heavy cal- 

 careous loam soil in growing plant and ratoon canes using 2-oz. dynamite 

 cartridges inserted 2.5 ft. deep gave results which are not considered remuner- 

 ative. In similar experiments on heavy clay soil an increase was obtained 

 in the ratoon crop and a decrease in the plant cane crop. 



Gravel as an aggregate for concrete, H. H. Schofield and C. C. Brown 

 (Munic-ipal Engin., 50 (1916), No. 4, pp. 135-137). — A study of existing data 

 on gravel and sand for concrete is reported. The results are taken to indi- 

 cate " that there is need of an investigation for the purpose of fixing a 

 rational specification for gravel for concrete. Such a specification should take 

 into account, among other things, the durability of the particles, the grading, 

 the cleanness, and the proportions for different classes of natural gravels and 

 for different classes of work." 



Amount of water to use in concrete, E. McCullough (Cement Era, I4 

 (1916), No. 5, pp. 50, 51). — The author reviews his practical experience and 

 reports the results of experiments in which it was found that slightly less 

 than 6 lbs. of water per cubic foot of loose materials produced the ideal mix- 

 ture for concrete roads. It was also found that a full minute of mixing was 

 necessary to get the water distributed through the mass. 



Making mortar impervious and anthracenic oil, R. Feret (Ann. Fonts et 

 Chauss^es, 9. ser., 28 (1915), pt. 1, No. 20, pp. 51-71). — Experiments with three 

 Portland cements to determine the influence on the strength and properties of 

 the mortar of the addition of anthracenic oil for waterproofing purposes are 

 repored. 



In the first series of experiments a mortar composed of 1 part cement to 3 

 parts of coarse sand was used, to which the oil was added in amounts of 5 and 

 10 per cent of the weight of the cement used. It was found that the use of the 

 oil slightly increased the total volume of the mortar without markedly modi- 

 fying the density. Mortars containing oil were less porous after a week than 

 those without oil. The tensile and compressive strengths of the mortars were 

 considerably decreased, especially when 10 per cent oil was used. 



Tests of the permeability under heads of water varying from 20 to 70 meters 

 showed that oil-treated mortar stored 14 days in moist air and 14 days in 

 water was considerably more impervious than the mortar without oil. Mortar 

 stored 14 days in moist air and 38 days in water and containing 5 per cent of 

 oil was more pervious than the mix without oil at heads between 20 and 40 

 meters, but with higher heads the oil mixtures were less pervious. These re- 

 sults are taken to indicate that it is inadvisable to use more than 5 per 

 cent oil. 



