RURAL ENGINEERING. 891 



Roads (E. S. R., 19, p. 385), which it supersedes, and describes methods of 

 petrographic examination and classification of rocl^s used in road maliing with 

 other " facts of importance bearing on the relation of the physical proi>erties of 

 rocks to their mineral composition and structure." 



Highway bridg'es and culverts, C. H. Hoyt and W. H. Burr ( U. 8. Dept. 

 Agr., Office Pub. Roads Bui. 39, pp. 22, pis. Uu figs. 3). — This bulletin presents a 

 general discussion of the status of highway bridge and culvert construction, 

 summarizing data as to previous methods, and making suggestions as to 

 methods now in vogue and the assistance being rendered in such construction 

 by the OfRce of Public Roads of this Department. 



" The relation of culverts and bridges to the general movement for the im- 

 provement of our public liighways is intimate. The desirability and economy 

 of building these structures of durable and permanent material, or according 

 to intelligent or economic design, has not thus far been actually recognized in 

 practice throughout the United States. The expensive and unsatisfactory 

 method of repairing the old and inadequate structures of the past or of fording 

 the streams is still continued. Modern traffic now demands that the construc- 

 tion of bridges and culverts shall keep pace with industrial development." 



Descriptive catalogue of the road model exhibit (U. S. Dept. Agr., Office 

 Pub. Roads Bui. 36, pp. 20, pis. I'l, fig. 1). — This bulletin embodies data orig- 

 inally compiled, for use in explaining the exhibit of the Office of Public Roads 

 at the Alaska-Yukon-Pacific Exposition. It describes in detail the models used 

 to illustrate the construction of road foundations, earth, sand, clay, gravel, 

 macadam, and brick roads, and presents data as to road machinery. 



The use of concrete on the farm {U. 8. Dept. Agr., Farmers' Bui. //Gl, pp. 23, 

 figs. 10). — In this publication, which supersedes Farmers' Bulletin 235, pre- 

 viously noted (E. S. R., 17, p. 709), suggestions for mixing and handling con- 

 crete under farm conditions are presented. Data are given on the selection of 

 materials and the manufacture of concrete, the use of measuring boxes and 

 other equipment for mixing concrete, and the construction and use of forms. 



Silo construction, A. S. Kenyon {Jour. Dept. Agr. Victoria, 9 (1911), Nos. 

 7, pp. 1,92-503; 8, pp. 566-573, figs. 9).— Details are given for building steel, 

 cement, wood, and wood and iron silos. 



Reinforced brick silos, R. T. Archer {Jour. Dept. .If/r. Victoria, 9 {1911), 

 No. S, pp. 57-'i-576, figs. 2). — Details are given for the construction of an eco- 

 nomical type of brick silo, reinforced with galvanized wire. 



The plastered or Gurler silo, H. E. McNatt {Missouri Sta. Circ. .^8, pp. 

 107-ll-'i, figs. 9). — Directions are given for building the plastered or Gurler silo. 



The reinforced concrete silo, F. H. Demaree {Missouri Sta. Circ. 49, pp. 

 115-122, figs. 4). — Directions are given for constructing a reinforced concrete 

 silo. A reinforced stone silo in use on the college farm at Columbia, Mo., is 

 illustrated and briefly described. 



Poultry house constniction, D. O. Barto {Farmers Voice, J,9 {1911), No. 

 IIJ/, pp. 3, 13, fig. 1). — A discussion of poultry house construction. An open- 

 front, " half-monitor " type of poultry house constructed of hollow cement 

 blocks, recently built at the Illinois Station, is illustrated and described. 



[Design for farm buildings on small holdings] {Country Life [London], 

 30 {1911), No. 756, pp. 11*, 12*, fig. 9). — This plan for a cottage, barn, and out- 

 buildings for an English holding of about 50 acres received the first prize in 

 the competition of the recent show of the Royal Agricultural Society of Eng- 

 land. 



The sanitary privy, C W. Stiles and L. L. Lumsden {U. S. Dept. Agr., 

 Farmers' Bui. 463, pp. 32, figs. 9). — Soil pollution and the diseases spread from 

 man to man in this way are discussed, the various kinds of privies described. 



