COST AND UTILIZATION OF POWER ON FARMS. 
53 
Table 40. — Effect of number of days of work per year 
plowing. 
on cost c 
/ using 6 
-plow tractors for 
Number 
of 
tractors. 
Annual cost. 
Daily cost 
(depre- 
ciation, 
interest, 
and 
repairs). 
Cost for plowing. 
Days of work per 
year. 
Depre- 
ciation. 
Interest. 
Repair 
and 
upkeep. 
Total. 
Per day. 
Per acre. 
33 
30 
22 
11 
8 
$183 
204 
257 
239 
261 
$44 
48 
50 
46 
52 
$29 
42 
39 
48 
58 
$256 
293 
346 
332 
371 
$21. 07 
11.72 
10.17 
7.58 
6.22 
$25. 88 
17.37 
15.87 
13.16 
11.61 
$3.13 
20 to 29.9 
2.13 
30 to 39.9 
1.78 
40 to 49.9 
1.58 
1.29 
RELIABILITY OF TRACTORS. 
The reliability of a tractor has a very decided effect upon its 
profitableness. In order to obtain definite information on this point 
each farmer visited was asked how many days during the year his 
tractor was not in running order when needed. On the average, the 
286 tractors were out of commission when needed 1.9 days during 
the year. One hundred and fifty-three, or 53 per cent of the total, 
were always ready for work when needed, and 54, 19 per cent of the 
total, were out of commission more than 2 days. 
There was little difference in this respect between the 2-plow and 
the 3-plow machines. On the average, the 2-plow machines were 
out of order when needed 1.8 days during the year and the 3-plow, 
2.1 days. Just 50 per cent of the smaller machines and 60 per cent 
of the larger ones were not out of commission at all. The age of the 
tractors likewise had no marked influence upon their reliability. 
Forty-one of the 106 which had been in use just one year and 15 of 
the 31 which had been in use over 3 years were out of commission 
at least one day. 
The actual number of days the 174 two-plow tractors and the 104 
three-plow tractors were out of order during the year is shown in 
Table 41. 
Table 41. — Number of tractors that were out of order different numbers of days. 
Days out of order. 
Number 
of 2-plow 
tractors. 
Number 
of 3-plow 
tractors. 

87 
56 
11 
12 
8 
62 
lor 2 
22 
3or4 
3 
5 or 6 
9 
8 
Most of the men whose tractors were out of commission more than 
two days had bad breaks while the machines were being used, and it 
was impossible to procure repair parts or the services of experts 
promptly. A delay of one or two days may not result in any serious 
loss, but a tractor which is out of commission a week or more at a 
time when its services are needed can scarcely be considered profitable. 
