292 LOGGING 
to making an estimate of the cost of moving earth and rock. 
The cubic yardage is computed from cross sections^ taken along 
the proposed grade at each station on level or fairly level ground, 
and at every point where there is a decided change in the con- 
figuration of the surface. 
BIBLIOGRAPHICAL NOTE TO CHAPTER XVII 
Clark, E. T.: Pacific Coast Logging. West Coast Lumberman, May 1, 
1920, pp. 81 to 92. 
Ellis, L. R. : Necessity for an Accurate Topographic Map in Logging 
Operations. Timberman, July, 1911, pp. 49-53. 
Henry, H. P.: Advantages of Topographic Surveys and Logging Plans. 
The Timberman, August, 1912, pp. 65-67. 
Peed, W. W.: Necessity for the Logging Engineer in Modern Logging 
Operations. The Timberman, August, 1910, pp. 47-49. 
Rankin, R. L.: Practical Topographical Surveys for Building Logging 
Roads. The Timberman, March, 1912, p. 27. 
Van Orsdel, John P. : How to Obtain the Highest Practical EflBciency in 
Woods Operations. The Timberman, September, 1910, pp. 48-51. 
Van Orsdel, John P.: Topographic Survey and its Economic Value hi 
Logging Operations. The Timberman, August, 1910, p. 64. 
Wood, A. B. : Accurate Topographic Map is a Good Investment in Logging 
Operations. The Timberman, August, 1912, p. 67. 
1 See "Earthwork and its Cost," by H. P. Gillette. McGraw-Hill Book 
Co., New York, 1912, pp. 175-182. "Highway Construction," by Austin 
T. Byrne. John Wiley and Sons, N. Y., 1902, pp. 447-454. "Theory and 
Practice of Surveying," by J. B. Johnson. John Wiley and Sons, New 
York, 1901, pp. 438-471. 
