156 POWER AND THE PLOW 



board plow, the disk will work, and apparently with much 

 less draft. The manufacturers of both disk and moldboard 

 plows are now recommending generally the use of the latter 

 for soils where it does good work. " This opinion is supported 

 by that of other prominent agricultural engineers, and may be 

 accepted as presenting adequately the adaptation of the two 

 types. 



One of the earliest patents in disk plows was granted to 

 M. A. and I. M. Cravath, of Bloomington, 111. Their plow 

 consisted of three disks, each cutting a narrow strip, and proved 

 that the principle could be applied in practice. It was defec- 

 tive in means for counteracting the side pressure. J. K. Under- 

 wood obtained several patents, including one for a three-wheeled 

 frame. D. H. Lane proposed to keep the plow in line with 

 the furrow by a wheel running in the rear of the disk. M. T. 

 Hancock finally succeeded in making the disk plow practical, 

 and it now has a wide popularity in sections where condi- 

 tions favor its use. 



The development of engine gang plows, which was the 

 logical outgrowth of the extension of traction plowing, has 

 largely taken place since the beginning of the twentieth cen- 

 tury. The introduction of a new source of motive power 

 involved the plowmaker in new difficulties. The hitching of 

 modern horse plows behind engines resulted in outfits as crude 

 and unwieldy as oxen and the "Bull" plows of a century pre- 

 vious. Fortunately, Yankee invention, sharpened by com- 

 petition, aided by marvelous manufacturing equipment, and 

 directed by the far-seeing eyes of up-to-date sales and experi- 

 mental organizations, was quicker to respond to the new need, 

 and in less than a decade the plow has again caught up with 

 the motive power in its state of perfection. 



No one man can be given credit for any important step in 

 the development of the engine gang: it was rather the work of 

 many minds, impressed all at once with a new, swift-arising 

 situation. The early types were of inflexible construction^ 



