592 EXPEEIMENT STATION EECORD. 



further development of the Leucocytozoon in Schaudinn's sense was observed in 

 C. pipiens and 8. caloptis, that is, the formation of large ookinetes and later of 

 large slim flagellates which progressed like spirochetes. Schaudinn's work on 

 alternation of generation and host in trypanosome and spirochete infection 

 could thus in important points be confirmed." 



RURAL ENGINEERING. 



Progress and present status of the good roads movement in the United 

 States, L. W. Page {U. 8. Dcpt. Agr. Yearbook 1910, pp. 265-27.',).— This article 

 briefly summarizes the history of road development in this country, and dis- 

 cusses the outlook for the future. 



" The present trend of road affairs throughout the various States is toward 

 a reform in administration and the adoption of a more progressive policy. 

 The old system of paying road taxes in labor has proved inefficient and is be- 

 ing rapidly discarded for the better plan of requiring all road taxes to be paid 

 in cash. It is also apparent that the State will ultimately be the unit of ad- 

 ministration and will largely control and direct road work in the counties and 

 townships. A reduction in the number of road officials is also inevitable, and 

 knowledge and skill in road building will be required of each official." 



Special road problems in the Southern States, D. H. Winslow ( U. 8. Dcpt. 

 Agr., Office Pub. Roads Circ. 95, pp. 15, figs. 13). — This circular discusses a 

 number of road problems encountered in the Southern States and suggests 

 comparatively simple and inexpensive remedies available by the use of local 

 materials and labor. These include methods of draining a flooded road by rais- 

 ing one side with logs, stones, or similar material ; the construction of road- 

 beds, with a V-shaped foundation filled with rocks, brickbats, or sand to serve 

 as a drain in swamp sections and low levels; and the protection from erosion 

 of roads and ditches by the use of planks or trenches filled with logs. 



Progress reports of experiments in dust prevention and road preservation, 

 1910 (U. 8. Dept. Agr., Office Pub. Roads Circ. 9-'i, pp. 56). — Experiments con- 

 ducted during the summer of 1910 are reported, together with supplementary 

 observations on experiments previously noted (E. S. R., 23, p. 489). 



In the tests at Ithaca, N. Y., in cooperation with Cornell University for the 

 purpose of ascertaining the relative value of different road binders under 

 various conditions, their average total cost per sq. yd. was as follows: Pene- 

 tration method, oil-asphalt 79.1 cts., refined asphaltic preparation 78.3-1 and 

 63.4 cts. ; prepared-filler method, oil-asphalt 83.69 and 92.34 cts. ; and mixing 

 method, oil-asphalt $1.14 and $1.03, refined semiasphaltic oil $1.0.5 and 98 cts., 

 and refined water-gas tar 93.37 and 90.87 cts. 



Tests with tar and oil preparations at Kuoxville, Tenn., showed a total cost 

 per sq. yd. of 60.04 cts. for i-efined coal tar, 53.98 cts. for refined tar prepara- 

 tion, and 53.71 cts. for oil-asphalt. All the treatments appeared satisfactory 

 when last inspected. 



A .300-ft. section at Ames, Iowa, was surfaced with gravel and oil-asphalt 

 at a total cost of 17.782 cts. per sq. yd. An oil-gravel-macadam treatment at 

 Boise, Idaho, cost a total of 28.83 cts. per sq. yd. 



In a continuation of the trials at Washington, D. C, concentrated waste 

 sulphite liquor and semiasphaltic oil emulsion were used at costs ranging from 

 3.26 to 14.83 cts. per sq. yd. Somewhat better results were obtained from the 

 materials when used alone, as the emulsion would, to a considerable extent, 

 waterproof the road surface and prevent proper absoiiition of the sulphite 

 liquor in later treatments. Treatments with oil-cement-concrete ranged in cost 

 from $1.15 to $1.26 per sq. yd. with fluid residual petroleum, and from $1.21 to 



