RUEAL ECONOMICS. 393 



larly adapted for stopping up gullies and for the protection of lands which tend 

 toward gullying. It is pointed out in this connection that the soil in the bottoms 

 of gullies is usually sufficiently fertile for the growing of tlie above-mentioned 

 plants. 



The law of highways, "W. W. Mackenzie (London: Buttcrworth d- Co., 1911, 

 16. cd., pp. CXIV-\-12.'>2). — This is the sixteenth edition of this bODk, covering 

 English laws in regard to highways, main roads, streets, and bridges. It is 

 divided into two sections, the first dealing with the law of highways independ- 

 ent of statute and the. second with statutes relating to highways, main roads, 

 streets, and bridges. 



The chapters under the first division are highways in general; dedication of 

 highways; ownership of the way; repair and nonrepair of highways and 

 bridges, and remedies for nonrepair; obstructions and nuisances; and extin- 

 guishment and diversion of highways. Under the second division the chapters 

 are highways, main roads, and streets; locomotives on highways; highways in- 

 terfered with by railways; tramways on highways; and bridges. 



Report of the state commission of highways (N. Y. Rpt. State Com. High- 

 irrt )/•'?. 1912, pp. 69lt, pU. 26). — This is a report of the activities of the commis- 

 sion during the year 1912. 



Road models (U. S. Dept. Agr. Bui. 220 {1915), pp. 2Jt, pU. 13, figs. 2).— 

 This is a revision of Bulletin 47 of the Office of Public Roadg of this Depart- 

 ment, previously noted (E. S. R., 28, p. 890). 



Surfaces or floors for bridges, C. Oldee {Good Roads, n. set:, 9 {1915), No. 6, 

 pp. 60-63, figs. 9). — The author relates the results of his experience regarding 

 floors for highway bridges and concludes that ordinary plank floors having an 

 average life of not more than three and one-half years are to be avoided when 

 possible. 



" With the exception of the floor with the bituminous surface, the cost of 

 the floor increases as the weight decreases, and yet the cost of the entire super- 

 structure decreases as the weight of floor decreases. The saving in cost for the 

 lighter floors increases with an increase in the unit cost of structural steel 

 in place, and decreases with an increase in the cost of the materials used in 

 such floors. In reflooring old steel bridges of satisfactory design, a creosoted 

 subplank with bituminous wearing surface has been found to give reasonable 

 service. . . . The cost of maintaining the bituminous surface is only about 

 20 per cent of that of an ordinary plank floor. Tliere seems to be no place in 

 the economic design of new highway bridges for floors consisting of a creosoted 

 plank subfloor with a brick wearing surface." 



Use of the Abney hand level, T. F. Hickerson (2V". C Geol. and Econ. Sur- 

 vey, Good Roads Circ. 99 {1914), PP- 6, figs. 7). — This circular describes a hand 

 level, for use in road engineering, which not only gives a level but also an 

 inclined line of sight by means of a vertical arc graduated in degrees and 

 minutes and a vernier reading to five minutes. 



RURAL ECONOMICS. 



Principles of rural credits, J. B. Morman (New York: TJie Macmillan Co., 

 1915, pp. XVIII-j-296).—'i'he author describes the methods of financing farmers 

 in European countries, indicating how the different forms of credit are made 

 available to them. He claims that the first step for placing rural credit on a 

 firm basis in the United States and Canada is the organization of farmers into 

 cooperative societies. This should be brought about not only by the farmers 

 themselves, but encouraged by state and national laws. With a view to their 



