viii THE PREFACE 



cooperate efficiently in the work. Engineers employed in 

 agricultural work usually spend a large portion of their 

 time in collecting data that should have been collected and 

 supplied by the landowner. A study of soils, classification of 

 lands, and specific problems on any individual tract of land 

 made by the agriculturist will greatly lessen the expense of 

 improvements that involve engineering assistance. In the 

 services of an engineer it is his experience and judgment 

 that are needed and not merely the operation of the instru- 

 ment in the field. The most expert instrument man might 

 be a very undesirable engineering advisor. The trained 

 eye and judgment of the professional engineer cannot with 

 economy be acquired by the landowner or agricultural stu- 

 dent, and for this reason no attempt has been made to 

 incorporate in this volume instructional matter on surveying. 

 In the preparation of Engineering on the Farm the files of 

 the Division of Agricultural Engineering, Department of 

 Agriculture, University of Minnesota, have been freely 

 drawn upon for illustrations and other data. Use has also 

 been made of unprinted manuscripts and bulletins published 

 by the authors and their co-workers in this division, par- 

 ticularly "Rope and Its Use on the Farm," by J. B. Frear, 

 and "Cement and Its Use on the Farm," by E. C. Crane. 

 All of these data were especially prepared in the division to 

 accomplish the same purpose that is sought by this text. 

 The authors wish to acknowledge their indebtedness to 

 Miss Hazelle E. Baird for suggestions on the organization 

 and English of the manuscript and for proofreading, and 

 to the following members of the Division of Agricultural 

 Engineering: L. R. Whitson, instructor in drawing; E. C. 

 Crane, assistant engineer; and George F. Krogh, drafts- 

 man. The courtesy of the Du Pont de Nemours Powder 

 Company, the Western Electric Company, the International 

 Harvester Company of America, Deere & Webber Company, 

 J. I. Case Threshing Machine Company, Inc., and the Link 

 Belt Company is acknowledged for the use of cuts. 



John T. Stewart 

 St. Paul, Minnesota 



