788 EXPERIMENT STATION RECORD. 



equation of the drillers, and the condition of the drill as to sharpness and 

 dullness. 



[Standard tests for brick] (Brick and Clay Rcc, 48 (1913), No. 3, pp. 272, 

 273). — Specifications are given, as suggesteid by the American Society for Test- 

 ing Materials, which cover transverse, freezing, compression, and absorption 

 tests and classification and sampling for vitrified and hard burned brick and 

 common brick first and common brick second. 



The part played by water in macadam road construction, W. G. Feabn- 

 siDES (Surveyor, U (1913), No. lUl, pp. 808-811, fig. Jf).— The author deals 

 with the limitations of water as an essential constituent in macadam road 

 construction, taking up the chemical disintegration of road stones, physical 

 characteristics of water in roads, behavior of water-bound materials, the tensile 

 and crushing strength of road stone, potholes, foundation stone, subcrust dew, 

 and frost. The conclusions point to the importance of surface and under drain- 

 i\ge for roads, and to the fact that each and every road aggregate has a char- 

 acteristic optimum water pro])ortion for efficient service. 



Reinforced concrete bridges, F. Rings (Nmv York, 1913, pp. XI -\- 183, pis. 8, 

 figs. 365). — In this book it has been attempted to collect as much data and 

 material as possible relating to the design of reinforced concrete bridges, and 

 to publish the most important features and facts with which the designer of 

 bridges should be acquainted. The subject matter is presented under the fol- 

 lowing chapters : Bending moments, stresses, and strains ; loads on bridges and 

 external stresses; culverts, covering, tunnel, etc.; beam bridges; calculation of 

 girder bridges with examples; design of arched bridges and abutments, with 

 examples; theory of the arch; and formulas, notes, schedules, and useful in- 

 formation. 



Use of wind motors in Eg-ypt, Delacroix-Mars y (Bui. Union Agr. Egypte, 

 10 (1912), No. 91, pp. 269-278; 11 (1913), No. 97, pp. U2-153) .—This article 

 discusses the generalities of the problem of the utilization of wind power in 

 Egypt and its possibilities, particularly for pumping for both drainage and irri- 

 gation. Results of irrigation experiments led to the conclusion that this method 

 may be employed in the spring in Upper Egypt in places where the wind is 

 strong and blows dally, and that under certain conditions wind power may be 

 applicable for drainage pumping in Lower Egypt. 



Central [electric] station practice of Windsor, Vt. (Elect. World, 62 (1913), 

 No. 23, pp. 1153-1159, figs. 20). — This article describes the development of a 

 small electrical central station system, supplying electricity to a manufacturing 

 and rural community in the upper Connecticut Valley. Several fypical private 

 installations supplied with power by this system are illustrated and described. 



Lighting costs 15 cts. per kilowatt hour up to an energy consumption of 20 

 kilowatt hours per month, with a reduction in steps down to 6 cts. minimum 

 for over 350 kilowatt hours. Motor service prices have a base rate of 7i cts. 

 per kilowatt hour, discounted by 10 per cent steps up to 50 per cent off for 

 users of 2,000 kilowatt hours per month. The minimum charge for both light- 

 ing and motor service is $1 per month. 



Experiments in electro-culture near Dayton, Qhio, H. G. Dorsey (Elect. 

 World. 62 (1913), No. 24, pp. 1217, 1218, fig. l).—ln experiments conducted to 

 determine the effect of electricity and artificial illumination on growth of vege- 

 tation, the plats subjected to high-frequency electrification showed a greater 

 increase in yield than any of the others. Ruby light ranged second for rad- 

 ishes, while violet light was second for lettuce. The edible portion of lettuce 

 grown on the high-frequency plat was 75 per cent greater than under natural 

 conditions. TevSts of high-frequency electrification on a larger scale showed an 

 Increase in all garden crops except beans and peas. 



