20 BULLETIN 174, U. S. DEPAETMENT OF AGRICULTURE. 



FUEL SUPPLY. 



The showing made by the kerosene tractors in comparison with 

 those burning gasoline is of special interest in view of the compara- 

 tively recent introduction and development of the kerosene tractor. 

 A few years ago the supply of gasoline could not be increased 

 rapidly enough with the distilling systems then in use to meet the 

 requirements of the thousands of gasoline engines of all kinds being 

 manufactured. As a consequence, the price of gasoline gradually 

 increased. 



The engine manufacturers, therefore, fearing that the rise in the 

 price of gasoline would hurt the sale of their product, devoted their 

 efforts to developing an engine which would burn the heavier and 

 cheaper oils. At the same time the oil refiners bent their efforts 

 toward developing a process which would produce a larger quantity 

 of the lighter fuels from the crude oils. Both have apparently 

 accomplished their purpose. Engines are now on the market which 

 apparently handle the heavier fuels with even better results in some 

 respects than are obtained from the engines burning gasoline, while 

 the oil refiners can now vary the quality of petroleum products 

 at will. 



On account of a misunderstanding which seems to be quite general 

 as to the present status of the fuel resources of this country, a short 

 discussion of the subject will be of interest. 



There seems to be a rather prevalent opinion that the supply of 

 fuel oil is rapidly nearing exhaustion, that the percentage of the 

 lighter fuels, especially gasoline, which can be obtained from the 

 crude oil, is growing less, and that the price of gasoline will there- 

 fore soon increase to such an extent as to prohibit its use in farm 

 engines. Statements to this effect are quite common and frequently 

 appear in print. vThile appearances may have indicated such a con- 

 dition a few years ago, recent developments in the petroleum indus- 

 try prove that such statements have no foundation in fact at the 

 present time. 



In the opinion of Dr. David T. Day, of the United States Geological 

 Survey, the known oil supply of this country will in all probability 

 be sufficient for the next 100 years. Dr. Day has been in charge of 

 the petroleum investigations of the Geological Survey for a number 

 of years and is qualified to speak with authority on this subject. As 

 to the percentage of gasoline that can be obtained from the crude 

 oils, Dr. Day, in a recent address before the Franklin Institute, spoke 

 as follows : 



This consideration naturall}- suggests the vital question of an adequate gasoline 

 supply. Even if we produce 25,000,000 barrels of gasoline in the next year this 

 would probably be too little for a year or two of further automobile progress. 



