PREFACE 



INSTRUCTION pertaining to Farm Machinery and Farm 

 Motors has been quite recently added to the agricultural 

 course in the majority of the agricultural colleges in the 

 United States. Although the need and importance of 

 such a study was self-evident, it was a new field, one in 

 which the knowledge pertaining to the subject had not 

 been prepared and systematized for instructional pur- 

 poses. The latest book on the subject of Farm Machinery 

 was written by J. J. Thomas in 1869, before the general 

 introduction of labor-saving machinery for farm work. 

 Many books have been written on the various motors 

 used for agricultural purposes, but it is not believed that 

 an attempt has been made to place in one volume a dis- 

 cussion of them all. The authors have felt the need of a 

 text for instructional purposes, and it is this need that has 

 prompted them to prepare this book. It is a revision of 

 the lecture notes used before their classes for several 

 years. These notes were prepared from a careful study 

 of all the available literature on the subject, and from 

 observation made in the field of the machines at work and 

 in the factories where they are made. 



A list of the literature consulted is given at the close 

 of the book. Free use has been made of all this as well 

 as all the trade literature available, and for this an 

 effort has been made to give due credit. Many of the 

 illustrations have been prepared from original drawings 

 by the authors; however, the larger number are those of 

 machines upon the current market. 



A discussion of all the farm machines did not seem 

 possible, and attention may be called to the omission of 



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