1917] 



RURAL ENGINEERING. 



<389 



group of 30 or more horses drawing a combine. . . , Throughout the tests it 

 was found that a 1,000-lb. pull for the two-horse team was a severe strain and 

 could be sustained for only a few seconds at a time." 



Tests made to measure the force required to pull the wagons over newly 

 plowed ground and over tall wheat stubble gave the following results : 



Draft tests on plowed ground and stubble. 



Type of wagon. 



On plowod ground: 

 Narrow-tire wagon 



Do 



Wide-tire wagon . . 



Do 



On stubble field: 



Narrow-tire wagon 



Do 



Wide-tire wagon . . 



Do 



How drawn. 



Straight ahead . 



In a curve 



Straight ahead. 

 In a curve 



Straight ahead . 



In a ciuve 



Straight ahead . 

 In a curve 



Wagon 

 emptj-. 



Pounds. 

 284 

 444 

 432 

 534 



198 

 264 

 310 



1-ton 

 load. 



Pounds. 



808 



910 



994 



1,038 



516 

 572 

 520 

 608 



2-(on 

 load. 



Pounds. 

 1,300 

 1,612 

 1,342 

 1,562 



872 

 1,122 

 1,018 

 1,216 



" Some tests were made by starting loads in different ways to find the force 

 required to start loads in ordinary practice. Out of 38 starts with the narrow 

 tire wagon, empty and loaded, the average starting force was 2.6 times the 

 average pull required to keep the wagon in motion after it had been started. 

 The average for the wide-tire wagon, under the same conditions, was 2.9. . . . 



" Some experiments were made to find out what could be done to lessen the 

 extra pull at the time of starting loads. Out of many trials, the force required 

 to start the wide-tire wagon slowly was found to be only 61 per cent of that 

 required for the ordinary start in which the reins were gathered up and the 

 load was supposed to move without delay. The force for an easy start, in the 

 case of the narrow-tire wagon, was only 58 per cent of that required for the 

 ordinary start. . . . The advantage of the slow start was fully demonstrated. 



" The plan of starting a load with a pull sidewise is fairly effective on hard 

 ground as it enables the team to get into motion slowly. In soft ground, how- 

 ever, when the front wheels are cramped to one side so that the hind wheels 

 do not follow in their tracks, there is great disadvantage in breaking out the 

 new wheel tracks." 



The average results of tests of plow draft are given in the following table : 



Draft of plows. 



Kind of land. 



Kind of plow. 



Depth. 



Number 

 of horses. 



Pull. 



Hill.... 

 Field... 

 Bottom 

 Bench.. 

 Field... 



Two 14-in. gang... 

 One 14-in. walking 

 One 12-in. walking 

 One 14-in. wheel.. 

 One 16-in. wheel.. 



Inches. 



7 

 8 



Pounds. 

 775 

 345 

 540 

 1,154 

 750 



" The pulls in pounds given in the table are averages of as many as 80 

 readings in some cases." 



Second series of tests of mechanical cultivation, E. Makre (Prog. Agr. et 

 Vit. {Ed. VEst-Ventre), 31 {1916). No. 20, pp. -'a6//-//6S).— Plowing tests on red 

 clay soil and productive I'esidual soil of a tractor having a 2 cylinder. 12-24 



