186 abstracts: references 



REFERENCES 



ENGINEERING. — Progress report of experiments in dust prevention and road 

 preservation, 1910. Circular 94, Office of public roads, Department of Agri- 

 culture. 1911. 



Results of spirit leveling in Ohio, 1909 and 1910. R. B. Marshall. Bulletin 

 U. S. Geological Survey No. 476. Pp. 79. 1911. 



Results of spirit leveling in Texas, 1896 to 1910, inclusive. R. B. Marshall. 

 Bulletin U. S. Geological Survey No. 468. Pp. 133. 1911. 

 Results of spirit leveling in South Dakota, 1896 to 1910, inclusive. R. B. Mar- 

 shall. Bulletin U. S. Geological Survey No. 472. Pp. 54. 1911. 

 Results of spirit leveling in Missouri, 1896 to 1909, inclusive. R. B. Marshall. 

 Bulletin U. S. Geological Survey. No. 459. Pp. 48. 1911. 

 Results of spirit leveling in Ioiva, 1896 to 1909, inclusive. R. B. Marshall. 

 Bulletin U. S. Geological Survey No. 460. Pp. 32. 1911. 

 Results of spirit leveling in Michigan and Wisconsin, 1897 to 1909, inclusive. 

 R. B. Marshall. Bulletin U. S. Geological Survey No . 461 . Pp.64. 1911. 

 Results of spirit leveling in Oregon, 1896 to 1910, inclusive. R. B. Marshall. 

 Bulletin U. S. Geological Survey No. 462. Pp. 82. 1911. 

 Results of spirit leveling in Arizona, 1899 to 1909, inclusive. R. B. Marshall. 

 Bulletin U. S. Geological Survey No. 463. Pp. 94. 1911. 

 Results of spirit leveling in New Mexico, 1902 to 1909, inclusive. R. B. Mar- 

 shall. Bulletin U. S. Geological Survey No. 464. Pp. 53. 1911. 

 Results of spirit leveling in Arkansas, Louisiana, and Mississippi , 1896 to 1909, 

 inclusive. R.B.Marshall. Bulletin U.S. Geological Survey No. 458. Pp. 

 79. 1911. 



Results of spirit leveling in West Virginia, 1909 and 1910. R. B. Marshall 

 Bulletin U. S. Geological Survey No. 477. Pp. 54. 1911. 



