PREFACE AND ACKNOWLEDGMENTS Xl 



Soil Analysis : 



W. B. Lewis, Ph.D., Humble Oil and Refining Company, Houston, 



Texas. 

 Eugene McDermott, M.S., Geophysical Service, Inc., Dallas, Texas. 

 E. E. Rosaire, Ph.D., Subterrex, Houston, Texas. 



Thermal Methods : 



J. N. A. van den Bouwhuijsen, Ph.D., International Geophysics, 

 Inc., Los Angeles, California. 



Drill Hole Measurements : 



E. G. Leonardon, M.S., Schlumberger Oil Well Surveying Corpora- 

 tion, Houston, Texas. 



R. R. Henquet, E.M., Schlumberger Oil Well Surveying Corp., Los 

 Angeles, California. 



J. C. Stick, Jr., B.Sc, Lane-Wells Company, Los Angeles, California. 



Physical Principles Applied to Production Problems: 



Howard C. Pyle, M.S., Continental Southern Oil Co., Los Angeles, 



California. 

 Everett G. Trostel, M.S., DeGolyer and MacNaughton, Dallas, Texas. 

 Daniel F. Elam, B.Sc, Halliburton Oil Well Cementing Company, 

 Duncan, Oklahoma. 



Permit and Trespass Practices, and Insurance : 



Howard Painter of Reynolds and Painter, Los Angeles, California. 



History of Geophysics : 



Katharine F. Jakosky, A.B., Los Angeles, California. 



Special mention is made of the excellent work of Dr. Florence 

 Ehrenkranz in checking the material included in the text, as well as her 

 many original mathematical contributions and suggestions. 



The original subject matter of this text is based upon lectures delivered 

 at and a manuscript submitted to the faculty of the College of Mines and 

 Engineering of the University of Arizona, in 1933. The author is indebted 

 to Dean G. M. Butler and the faculty of that college for permission to 

 use much of the material included in that manuscript. 



J. J. Jakosky. 

 July, 1940. 



