384 EXPERIMENT STATION RECORD. [Vol. 41 



conditions, B represents the original investment, and C repi-esents tlie rate of 

 interest. Annual costs for repairs ranged from about $100 to as high as $800 

 or $900, Where trucks were kept in a constant state of repair the annual 

 repair charge was relatively small. For solid tires it was found that this 

 cost ranged from 1 to 4 cts. per mile. It was found that the solid tire is more 

 commonly used because it is more adaptable and cheaper than the pneumatic, 

 does not suffer from blow-outs or puncture, and stands up well on bad roads 

 and under very heavy loads. 



Numerous other suggestions and information are given covering cost- 

 accounting, delivery methods, collection and deliveiy arrangements, etc. A 

 standard bill of lading, a driver's daily report card, and insurance provisions 

 covering shipments are suggested. 



It is concluded that the chief factor limiting development in the field of rural 

 motor hauling is the cost of operation as compared with that of railroads, 

 electric lines, and boat lines. The limiting factor second in importance is 

 considered to be the condition of average country highways. Financial re- 

 sponsibility is considered the limitation third in importance. It is generally 

 concluded that under proper conditions, and where a fair knowledge of the 

 limitations and difficulties obtains, motor truck transportation premises to play 

 an important I'ole in rural districts. 



The farm tractor in the Dakotas, A. P. Yeekes and L. M. Chuech ( TJ. S. 

 Dept. Agr., Farmers' Btil. 1035 {1919), pp. 32). — This reports data obtained from 

 over 300 tractor owners in North and South Dakota, based on operating results 

 during the fall of 1917 and spring and fall of 1918. 



It was found that the principal disadvantage of the tractor in the Dakotas 

 lies in its inability to do satisfactory work under moist soil conditions. Diffi- 

 culty of efficient operation was the next disadvantage. 



Of the farmers reporting, 44 per cent were able to increase the farm acreage. 

 Over half of those reporting owned 3-plow machines, the remainder being 

 about evenly distributed among the 2-plow, 4-plow, and larger sizes. After 

 using these tractors nearly the same percentage recommended the 3-plow 

 ti'actors as owned them, 30 per cent recommended the 4-plow tractor, and only 

 5 per cent recommended the 2-plow tractor. The minimum number of acres on 

 which the 2, 3, or 4-plow outfits were profitable were 185, 225, and 314 acres, 

 respectively. 



The tractors were used an average of 50 days annually, about 40 days on 

 home work and 10 days on custom work. The number of days the tractor was 

 used on home work increased rapidly with the size of farm, and the number 

 of days on custom work decreased gradually. 



The average quantity of fuel consumed per acre in plowing was 2i gal. 

 The fuel cost per acre for plowing averaged about 38 cts. for kerosene and 60 

 cts. for gasoline. The average cost per acre for plowing for fuel, oil, and 

 grease was about 78.5 cts. where gasoline was used and 49 cts. where kero- 

 sene was used. The cost for repairs for 2, 3, and 4-plow outfits averaged 15, 

 13, and 11 cts. per acre plowed, respectively, and the corresponding average 

 depreciation, assuming a 9-year life for a tractor, was estimated at 41, 36.5, and 

 31f cts. The cost per acre for man labor at .$4 per day for the 2, 3, and 4-plow 

 outfits averaged 63.5, 47, and 36| cts., respectively, and interest at 6 per cent 

 averaged 11, 10, and 8.5 cts., respectively, per acre plowed. The total approxi- 

 mate cost of plowing an acre, using kerosene for fuel, averaged $1.80, $1.56, 

 and $1.38 for the 2, 3, and 4-plow outfits, respectively, and where gasoline was 

 used for fuel, $2.09, $1.85, and $1.67. Horses were displaced on only about 

 57 per cent of the farms where tractors wei*e used and where no increases was 



