46 



BULLETIN mi, IT. S. DEPARTMENT OF AGRICULTURE. 



were obtained. Interest was charged at 6 per cent on the average 

 investment. 



The total annual cost for depreciation, repairs, and interest was 

 divided by the number of days of work done by the tractor during 

 the year to obtain the cost per day of work for these items. To this 

 was added the cost of fuel and oil used per day to obtain the total 

 cost per day of use, and the sum divided by the number of acres 

 covered in a day to obtain the acre-cost of using the tractor on the 

 different operations. No charges for shelter, insurance, and taxes 

 are included. These charges would amount to only a small per- 

 centage of the total cost, however. 



In the following discussion the 2-plow and 3-plow machines are 

 treated separately in order to afford a comparison between the two 

 sizes. On all the 286 farms there were only 8 tractors of. sizes other 

 than these (see page 9), and no figures for them are given. The 

 286, however, are included in every case in the figures for "All 

 tractors." 



First cost. — The average first cost of the 174 2-plow machines was 

 $972; of the 104 3-plow machines, $1,354, and of the entire 286, 

 $1,140. These figures include the first cost of all extra equipment, for 

 the tractors themselves, but do not include the cost of new implements 

 purchased. Every farmer owned a tractor plow and a majority had 

 also purchased tractor disks. Some had also procured belt machines 

 for use- with the tractors. On the average the amount which had 

 been spent by the owners of the 2-plow tractors for implements and 

 machines was $271, and by the owners of 3-plow tractors $430. For 

 all farms this item amounted to an average of $343. 



Life. — The average estimated life of the 286 tractors was 6.7 years. 

 The average of the estimates for the 2-plow tractors was 6.4 years, 

 and for the 3-plow 7.0 years. 



Table 31. — Estimated life of tractors. 





Estimated life of tractor (years). 



Xiunher of owners 

 estimating life of 

 tractor as speci- 

 fied. 





Owners 1 Owners 

 of 2-plow of 3-plow 

 Tractors, tractors. 



3 



,1 



51 



33 



17 

 22 



7 

 21 



"> 



4 



i 



5 



30 



6 



13 



7 



13 



8 



11 



9 



2 



10 



Ifi 



11 





L 

 3 

 3 



12 



1 



15 







