398 EXPERIMEKT STATION RECORD. [Vol. ;^0 



ceived froiu 215 owuors. TTnf;iv(»r;il)lo reports wen^ follDwed Ity poi'somil 

 interviews, and it was usually found that the owner was either not mukiug a 

 success of any farm work or, while a good farmer, he was not a mechanic 

 and depended upon inexperienced men to handle the tractor. 



Of the total number of owners reporting for the period 1912-1916, 68.6 per 

 cent considered the tractor a good investment, and of the owners reporting for 

 1915-16, 76.5 per cent so considered it. All things considered, the tractor was 

 thought to be more satisfactory than the horse by 54.4 per cent of the total 

 number reporting, and by 61.1 per cent of those reporting for 1915-16. As to 

 the cost of operation and maintenance, 65.8 per cent reported in favor of the 

 tractor. From the reports made by the total number reporting, it was 

 thought that the tractor would not be a good investment on farms under 270 

 acres, but the 1915-16 reports indicated 230 acres to be sufficiently large. 



The machines were used an average of 66 days a year. The average length 

 of day was 11,8 hours, with 1.25 hours additional required for oiling and 

 general care. The average size of tractors was from 10,31 to 22.1 horsepower, 

 and the average cost of tractors $564,23. The average cost of repairs was about 

 $42.50 for the whole year. 



The average width of gang used for plowing was 4.46 ft. or four plows, 

 while that used for breaking was 5,2 ft. or about five plows. The rate of speed 

 traveled per hour was 2.48 miles for plowing and 2.24 miles for breaking. The 

 average amount of fuel used per day for plowing was 26.25 gal., at a cost of 

 $3.50, and for breaking 40 gal. at a cost of $6,96. The amount of lubricating oil 

 used per day for plowing was 1,77 gal, at a cost of 87.3 cts. ; and for breaking 

 2.52 gal, at a cost of $1.25. 



F. N, G, Kranich discussed The Tractor's Relation to the Farm and its 

 Machinery, It was pointed out that the relation of the tractor to the plow 

 is well established and that the plows now used are of special design, horse- 

 drawn gang plows being used in very few cases. It was considered doubtful, 

 however, whether or not the tractor will bring about similar changes in other 

 farm draft and belt power machines. Nearly all the seeding and harvesting 

 machinery in present use is built in vmits too small to be used economically 

 with the tractor, indicating the necessity of designing this type of machinery 

 so that it may be drawn either by horses or by a tractor. The relation of the 

 tractor to belt power machines does not necessitate a change in machine design, 

 but does necessitate a careful choice on the part of the purchaser as to size 

 so that the tractor will have ample power to drive the machines at their full 

 capacity. The necessity was also pointed out of selecting a tractor and the 

 machinery to go with it in sizes that will prove a paying investment on 

 the farm in question, and of making sure that this machinery will be used a 

 sufficient amount of time during the year to make the proposition a paying one, 



E. R. Greer, in a paper on Developments in Tractor Design, stated that the 

 developments during the past season have been mostly in the perfection of 

 details. There has been no radical change in the general design of tractors 

 and no type on the market has been eliminated because of its unfitness. An 

 improvement considered very important by the author is the general adoption 

 of a device for clearing the air of dust before it enters the engine cylinder. 

 It was stated further that all types of tractor motor may be equipped with 

 devices so that kerosene may be burnt successfully, but as a rule the power 

 capacity will be about 10 per cent less in burning kerosene than in burning 

 gasoline. 



In a paper on The Standardization of Gas Tractor Ratings, R. W. Olney 

 advocated the universal rating of tractors in terms of belt and drawbar horse- 

 power and drawbar pull, as previously explained (E. S. R., 35, p. 890). 



