74 FARM MACHINERY 



was made on clover sod, the plow being provided with a 



wheel coulter, the soil being drier than before. The fol- 

 lowing results were obtained : 



Total Draft 



Size of Furrow Draft per Sq. In. 



Clover sod without coulter 6.47" X 11.61" 714.35 10.80 



" with " 6.413" X 12.47" 664.82 8.616 



Difference 49-53 2. 184 



In these tests the coulter reduced the draft 25.34 per 

 cent. 



It is stated in the report of the trials of plows at Utica 

 that the total draft of a plow is divided as follows : 35 per 

 cent is used in overcoming the friction between the im- 

 plement and the soil, 55 per cent in cutting the furrow 

 slice, and 10 per cent in turning it. The accuracy of these 

 tests has been doubted by some, but the tests seem to 

 have been conducted with care, and they show the neces- 

 sity of keeping a sharp cutting edge. It is desirable that 

 data of this kind be obtained by tests made with 

 modern plows. 



no. Draft of sulky plows. It is often claimed that the 

 draft of sulkv plows is less than that of walking plnws^ 

 owing to the friction of the sole and landside being trans- 

 ferred to the well-oiled bearings of the carriage. But 

 (records show that there is no gain unless the weight of 

 the driver and the frame is deducted. But there is an 

 evident advantage in riding plows, even if the draft is 

 slightly greater on the team with the plowman riding 

 rather than walking, and the plow being handled^ with 

 equal facility. Though little information is at hand on 



I the subject, what there is seems to indicate that there is 

 only a slight difference in the draft of walking and riding 

 plows, in proportion to the amount of work done. 



in. The selection of a walking plow. The best in 



