FARM EXPERIENCE WITH THE TRACTOR. 33 



every 12 acres can not hope to produce crops as cheaply as his neighbor 

 with a 1,400-acre farm who has an invested capital of only $4 per 

 acre and who tills 32 acres with each unit of power. 



It is not surprising, therefore, that the owners of farms containing 

 640 acres or less do considerably more custom work than those with 

 larger farms, as the excess power must produce some income in order 

 to justify its maintenance. 



In this connection, it should also be noted that the repairs per acre 

 are considerably less for the large farms than for the small ones, which 

 naturally follows, in view of the difference in equipment. It is 

 probable that the repairs bear a closer relation to the size of the engine 

 than to the size of the farm, in view of the slight difference in the 

 number of days used. 



USE OF TRACTORS AT NIGHT. 



The number of men who used their tractors at night was found to be 

 surprisingly small (about 11 per cent in North Dakota and 14 per 

 cent in other States) and in most cases the number of nights used per 

 year was comparatively insignificant. While the tractor is theoreti- 

 cally capable of working night and day, it appears that night work 

 is seldom done. 



The explanation of this probably lies in the fact that in norma,! 

 years there is little need for operating at night, unless it be during 

 harvest, when it may be desirable to rush the work as much as possi- 

 ble in order to prevent loss from storms. However, tractors are not 

 extensively used for harvesting except in those sections where it is 

 practicable to use a combined harvester. Another reason for the 

 small amount of night work is the necessity of having two operating 

 crews for the outfit. This is obviously impractical in most cases. 



In order to ascertain whether any loss of efficiency occurs when 

 operating at night, a number of tractor owners who had operated at 

 night were asked for estimates as to the percentage of efficiency 

 compared with work done in the daytime. The average of these 

 estimates was 93.3 per cent. 



This slight loss in efficiency appears to be due almost entirely to 

 inability to watch the operation of the outfit as well as it can be done 

 during the day and the additional time required to make any adjust- 

 ments which may be necessary. 



Among some 70 men who were interrogated regarding night work 

 the opinion was almost unanimous that the motor developed more 

 power at night than during the day, some estimating the increase to 

 be as much as 20 per cent. 1 



1 This information was voluntary, the men having been asked simply for an estimate as to the efficiency 

 of the tractor at night. They offered their observations as to the increase of power at night as a phenomenon 

 which they could not explain. In view of the varying opinions of gas-engine experts on this point, the 

 unanimous observation of tractor operators that such an increase does occur is of interest. 



