100 



Utah Station, Bulletin No. 6, May 15, 1891 (pp 14). 



Trials of sleds axd tillage tools, J. W. Sanborn, B. S. — 

 Notes and tabulated data on tests of various kinds of sleds and harrows 

 with the dynamometer and in other ways. The following summary is 

 taken from the bulletin : 



(I) In the trial niaile, sleds drew harder than wajjonsover the same ground the pre- 

 vious fall under what seemed to be equally favorable conditions for each. 



(•2) Change of load from the front to the rear end of the sled did not materially 

 affect draft, as it did with wagons. 



(3) The friction due to the point of hitch of the horses or the relation of the power 

 to the load did not follow the same law as with wheels. The hitch for sleds seems 

 to be too low down as now made. 



(4) A load draws as easy with crooked shaft as with a straight hitch. 



(5) Draft varied with the sleds used and was least ou the shortest sled, but it is 

 not certain thai the length of sled was the determining cause in the trials made. No 

 other solution of the facts found w.as discovered. Future inquiry will be necessary 

 to determine with certainty the cause of the variations in draft between the makes 

 of sleds used. 



(()) Depth of cutting the ground, draft per square inch and per pound of soil moved, 

 looseness of soil, and evenness of bottom varied very widely in the various types of 

 harrows used. 



(7) The rolling cutters, especially those termed cutaway harrows, move the .soil 

 deepest and loosen it most, and in the form of the cutaway harrow dr.iw the ea.siest 

 of the class that penetrates deeply. 



(8) The spring-toothed harrows draw moder.itely " fine " to an average degree, 

 and till to an average depth, but leave the soil with an uneven bottom and more 

 compact than the class above name<l, while on newly plowed grass sward they tear 

 up the sod. For the cultivation of corn, they are very good implements, serving well 

 the functions required in tillage of crops. 



{[)) The 8(iuare-toothed and the smoothing harrows are superficial in their action 

 on plowed ground, run easy, Ijut compress the soil more than other classes, and are 

 therefore better adapted to loose soils and for putting in seeds than to do the tillage 

 work of soil fitting for crops. If present views regarding tillage are correct, then 

 these implements are utterly unfitted for the purpose when api)lied to nu)st soil.s. 



(10) When depth of cutting, ease of draft, evenness of bottom or of the top of 

 the unstirred soil, and looseness of soil are considered, the cutaway type of harrows 

 is the best of the several classes of tillage tools used by the writer for tlie prepara- 

 tion of the average soil for crops. It is believed that the work of this class of li;ir- 

 rows should always be supplemented by the smoothing harrow. 



(II) Harrows move less earth for a given amount of force than plows do, but, a^ 

 found in a previous trial, the force required for fitting the soil tor crops, when the 

 plow supplemented by the harrow, is used is practically uo less than when the har- 

 row alone is used. 



(12) Less force is required to fit a given surface area of soil for crops when the 

 harrow is used than when the plow is used. This fact admits of the use of some 

 substitute for the plow upon soils that do not require deep tillage, if, indeed, there 

 are such soils. 



(13) The relative efilcieucy of harrows varies on varying soils and on varying 

 conditions of a i*iven soil, the wedge-shaped teeth being at greatest disadvantage ou 

 hard soils. 



(14) The plow, acting as a wedge, compresses the particles nearer together as it 

 inverts the soil and divides only large masses ; therefore the harrow is the true imple- 

 ment for "fining" and loosening the soil, the plowing serving to fit the soil for ii> 



