436 Farm Mechanics. 



easily drew 11 tons, or 22 times the weight of the- animal, 

 and it is stated in the report that the horse could readily 

 have hauled 50 times his own weight. This would be, for a 

 1,000-pound horse, 25 tons, but of course with such a load 

 the road must be practically level, for a grade of one per 

 cent, would increase its draft 500 pounds. 



536, Draft of Wagon Shown by English Trials The 



power required to draw a four-wheeled wagon over roads 

 of different characters has been tested and the following 

 expresses the results in pounds per 2,000 Ibs. of gross load : 



On cubical block pavement 28 to 44 Ibs. per ton 



On macadam road 55 to 67 Ibs. p( r ton 



On gravel road 75 to 140 Ibs. pc r ton 



On plank road 25 to 44 Ibs. per ton 



On common dirt road 75 to 224 Ibs. per ton 



537. Draft With Different Widths of Tire. Prof. J. H. 

 Waters 1 has made an extended series of trials to test the 

 effect of the width of tires on the draft of loads under dif- 

 ferent conditions of road. He used always a net load of 

 one ton, but the 6-inch tired wagon was 245 pounds haavier 

 than the 1.5 inch, making the gross loads 3,225 and 2,980 

 pounds respectively, when the wagons were free from mud. 

 The following are his results : 



On macadam streets, wide tire 26 per cent, less than narrow tire. 



On gravel road, wide tire 24.1 per cent, less than narrow tire. 



On dirt roads, dry, smooth, free from dust, wide tire 26.8 per cent, 

 less than narrow tire. 



On clay road, with mud deep, and drying on top and spongy beneath, 

 wide tire 52 to 61 per cent, less than narrow tire. 



On meadow, pasture, stubble, corn ground and plowed ground 

 from dry to wet, wide tire 17 to 120 per cent, less than narrow tire. 



On the other hand he found that when the roads were 

 covered with a deep dust, or with a thin mud but hard be- 

 low, the narrow tired wagon gave the lightest draft. Also 

 when the mud was thick and so sticky as to roll up on the 

 wheel, loading it down, and again when narrow tired 

 wagons had made deep ruts in the road which the wide 



iBull. No. 39, Missouri Agr. Bxp. Station. 



