FAEM EXPERIENCE WITH THE TRACTOR. 13 



However, the life of a tractor can not be properly expressed in years 

 alone. The tractor is a machine; and, like all machines, its life 

 depends on the amount of work it does and on the care taken of it. 

 This life can be shortened by lack of proper care and by abuse in 

 operation. The number of years a tractor will be available for work 

 on a farm, therefore, depends only partly on the hours it will be 

 required to work each year. But if the machine is given proper care, 

 both when idle and when in use, the amount of work done per year 

 will be the principal factor in determining its length of useful life. 

 Table IV shows that during the working life of a tractor in ordinary 

 farm service the amount of service obtained covers from 3,600 to 

 11,000 working hours, including both traction and stationary work. 

 From these figures it is apparent that a tractor might be worn out in 

 less than two years if operated day and night continuously, while, 

 on the other hand, if used only intermittently its life may be extended 

 over a number of years, with proper protection from deteriorating 

 influences when not in use. It might seem at first thought that a 

 tractor could be made to last indefinitely by replacing worn-out parts 

 with new ones, but there comes a time when the cost of such replace- 

 ments becomes prohibitive and it is more economical to discard the 

 old tractor and purchase a new one. The tractor's life is, then, the 

 length of time it can be used before the repairs become so expensive 

 as to make its further use uneconomical. 



While Table III showed the number of owners who believe the 

 tractor to be a profitable investment, there were two related questions 

 submitted to the owners which are not shown in the tabulations. 

 These were "All things considered, is the tractor more satisfactory 

 than horses?" and "Is it cheaper?" The answers received to these 

 questions agree in many cases with those shown in Table III, but it is 

 interesting to note that among the men who believed the tractor to be a 

 good investment the number reporting the tractor to be cheaper than 

 horses is greater than the number stating that it is more satisfactory 

 than horses. On the other hand, among the men believing that the 

 tractor is an unprofitable investment, the number stating that it is 

 not cheaper than horses is less than the number stating that it is not 

 as satisfactory. 



This would seem to indicate that among the successful owners the 

 tractor's economy has been a greater factor than its general utility, 

 while among the unsuccessful owners the expense has been a more 

 important consideration than its unsatisfactory operation. 



FUELS USED. 



Table V shows the number of engines in each group which burn 

 gasoline, kerosene, and motor spirits, respectively. From this 

 table it will be seen that the percentage of kerosene tractors is slightly 



