JOINALOFAGRKMTIALISEMCH 



Vol. XII Washington, D. C, January 28, 1918 No. 4 



A STUDY OF THE PLOW BOTTOM AND ITS ACTION 

 UPON THE FURROW SLICE ^ 



By E. A. White, ^ 



Assistant Professor of Farm Mechanics 



College of Agriculture of the University of Illinois 



INTRODUCTION 



The most ancient records show that from a very remote period man 

 has used the plow, in one form or another, to assist him in stimulating 

 the earth to bring forth a more bountiful harvest. As has been the 

 case in many other lines of endeavor, theory has trailed far behind 

 observation and experience in developing this implement. In fact, as 

 far as can be ascertained, it was not until the last half of the eighteenth 

 century that any serious attempt was made to develop a plow bottom 

 from a theoretical standpoint, and even then the productions of Jefifer- 

 son, Lambruschini, Small, Rham, and others can not be considered as 

 thoroughly grounded upon well-developed theories; rather their works 

 should be looked upon as hypotheses (fig. i). Experience in the field 

 generally proved that the machines designed by these men were not all 

 that could be desired — ^for example, it is reported ^ that when Lam- 

 bruschini's helicoidal moldboard was taken into the field for trial the 

 driver of the draft animals immediately observed that the force required 

 to move this plow was too great for the results obtained. To be sure, 

 geometrically exact moldboards furnished the basis in many instances 

 for more perfect developments, but the results obtained by empirical 

 plow designers who worked in the field were so far superior to the results 

 obtained by the men who worked in the laboratory that the theorists 

 were soon completely outstripped and even held up to ridicule by the 

 men who developed their machines in the hard school of experience, 

 until at the present time we find special types of plow bottoms designed 



1 Approved for publication in the Journal of Agricultural Research by the Director, Cornell University 

 Agricultural Experiment Station. 



* The experimental work for this paper was done under the direction of Prof. H. W. Riley, of the De- 

 partment of Rural Engineering, Cornell University, and the mathematioal developments were prepared 

 under the supervision of Prof. F. R. Sharpe, of the Department of Mathematics. In addition to the above, 

 grateful acknowledgments are given to the following: To Prols. James AIcMahon and Virgil Snyder, of 

 the Department of Mathematics, for their most timely and helpful suggestions; to Mr. J. E. Reyna, 

 Instructor in Drawing, College of Agriculture, Cornell University; and to Mr. L. S. Baldwin, Instructor 

 in General Engineering Drawing, University of IlUnois, for making the drawings. 



3 Lambruschini, R. d'ijn nxjovo orbcchio da coltri. In Gior. Agr. Toscano, v. 6, p. 37-80. 1832. 



Journal of Agricultural Research, Vol. XII, No. 4 



Washington, D. C. Jan. :8, 1918 



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