164 



Report on Trials of Plows. 



and the draught was 350 pounds, which is only 14 pounds more 

 than when they were walking slowly. 



A second trial was had in an adhesive loam, in so bad a condition 

 that the polished mould-board was completely encrusted with earth. 

 Hart's plow was selected for the experiment, and one hundred 

 and ten yards, or one-sixteenth of a mile, were accurately meas- 

 ured off. At the first trial the horses traveled the distance in 

 two minutes and forty seconds, being at the rate of one and a 

 half miles in an hour. The dynamometer showed a draft of 322 

 pounds, the furrow being four inches l)y nine inches. At the 

 second trial the distance was done in two minutes and twenty-five 

 seconds, being at the rate of one and three-quarter miles in an 

 hour. The furrow was of the same size, and the draught was 

 still 322 pounds as before. At the next trial the rate was one 

 minute and forty seconds, which is at the rate of two and three- 

 quarter miles in an hour; the draft, from some cause, was reduced 

 instead of being increased, and stood at 308 pounds. Finally the 

 distance was accomplished in one minute and five seconds, or at 

 the rate of three and a half miles in an hour. The draft was 

 indeed increased, but the increase Avas only 14 pounds, which 

 might ver}^ probably be due to an increased tenacity of the soil. 



The following table shows the time which would be required 

 for plowing an acre, with a furrow nine inches wide, at the differ- 

 ent rates of motion, exclusive of stoppages: 



Mr. Morton's experiments were first with a speed equivalent to 

 two and a half miles an hour. The furrow was four by nine 

 inches, and the draught was 378 pounds. At five miles an hour 

 the draught was 392 pounds. His experiments were made with 

 a self recording dynamometer, in which the pencil described the 

 extent of every oscillation. It is worthy of remark that these 

 oscillations were very greatly increased at the higher rate of 

 speed, ranging between the extremes of 210 and 644 pounds, 

 while at the lower rate the oscillations ranged from 280 to 504 

 pounds. 



