Supplementary Plow Trials. 281 



swim freely on the surface without any tendency to dip into the 

 ground, he proceeded to measure the surface draught and the 

 cutting action of the coulter seven inches beneath the surface of 

 the ground. The draught in this case was 3(34 pounds. The 

 draught when the coulter was removed and the plow was drawn 

 over the surface of the ground was 112 pounds, which, being 

 deducted from the whole draught, leaves 252 pounds as the 

 draught of the coulter. Mr. Stephens further states, that a well 

 trimmed plow, turning a furrow seven inches deep and ten inches 

 broad, was at Avork in the same field, the draught of which was 

 .only 364 pounds. The same plow, after the coulter was removed, 

 was put to plow a furrow seven inches by ten inches, and its 

 draught was also 364 pounds. It Avould, therefore, appear from 

 this experiment that the surface draught, and the coulter running 

 seven inches into the ground, required as much power as it does to 

 turn a complete furrow seven inches by ten inches. 



Expermient iVo. 111. — We desired to verify this experiment, 

 and we accordingly affixed a coulter which had been specially 

 prepared for the purpose to No. 65, so that it projected six inches 

 below the sole. The bridle of the plow was not long enough to 

 enable us to bring it into proper trim, so as to prevent it from 

 running into the ground, but finally, by attaching a chain to the 

 guides of the wheel it worked very satisfactorily. The draught 

 (including the surface draught) was 296 pounds; deducting the 

 surface draught, which is 77 pounds, we have 219 pounds for the 

 power consumed by the coulter, which is 33 pounds less than Mr. 

 Stephens found; but as his coulter ran one inch deeper than ours, 

 and would therefore necessarily consume more power, the agree- 

 ment is quite as close as could be expected. 



Experiment JSfo. 112. — We then removed the coulter, and 

 plowed a furrow six inches deep and eleven inches wide. The 

 draft was now 417 pounds, or 121 pounds more than was required 

 for the surface draught of the plow, and to cut six inches into the 

 ground. 



In order to complete this experiment on the influence of the 

 coulter, we should have plowed a few furrows of the same size, 

 with the coulter adjusted in the ordinary way; but the importance 

 of the experiment escaped our attention at the moment. 



Experiment JSfo. 113. — We thought of it afterwards, and tried 

 the experiment, but we were at that time plowing in a denser soil, 

 and the comparison was, therefore, not exact. The draught in the 



