PETROLEUM. 
31 
The automobile, of course, first by its novelty and later by its wide 
appeal, has been the prime mover in the automotive development. It 
would appear to be unnecessary to particularize as to the social value 
of the automobile, as this matter is common experience. It may be 
said, however, that apart from its purely luxury use, with which we 
are not here concerned, the automobile has served to enlarge the pos- 
sibilities of modern life, not merely by contributing pleasure, but in 
improving opportunities for physical and mental recreation, social 
contact, and business activity, with no small contribution toward 
facilitating the livableness of the modern city. The automobile has 
gone far on the road toward solving the problem of personal trans- 
portation. 1 
An important outgrowth of the automobile development has been 
the motor truck, now used in great numbers for city and suburban 
delivery service, and coming into prominence in the more populous 
country districts as an efficient agent for short-haul freight. The 
importance of this matter is suggested by the fact that the motor 
truck in 1917 hauled over 60 ton-miles of freight for each person in 
the United States. 2 The possibilities of the motor truck are still 
largely unrealized; its continued extension may be expected to re- 
place largely the short spur line of the railroad; and in connection 
with the growth of a network of good roads, a country-wide auto- 
truck utilization will furnish an efficient feeder system to the trunk 
transportation channels of the country. In respect to the prompt 
delivery of farm produce, whether to railways or directly to towns, 
the motor truck has an exceptionally useful opportunity. 3 The 
whole problem of food supply, indeed, is closely bound up with the 
matter of adequate facilities of transportation 4 and appropriate use 
of mechanical power, for both of which petroleum products have a 
tremendous field of unrealized usefulness. 
The tractor for farm use is a still more recent development than 
the motor truck and the growth in its utilization during the past 
few years, especially in the Middle West, has been great. Coming 
into play at a time when the national food problem has taken on a 
1 It is scarcely necessary to point out that the automobile supplements, but does not 
replace, the standardized service rendered by the steam passenger train and the electric 
urban and interurban lines. 
2 This was only a small fraction of the freight hauled by the railroads of the country, 
whose record in 1915 was 2,768 ton-miles per capita, yet the proportion is important 
and growing. 
3 The horse and mule for small-unit haulage are destined to pass in large measure ; 
they represent an engine consuming high-priced fuel useful otherwise as food, running 
24 hours a day whether used or not, and low geared with a capacity of only 3 to 4 
miles an hour at best. 
4 The problem of good roads has never received adequate attention in the United 
States. A striking example of the intricate interrelationships of industrial problems 
is afforded by the fact that good roads in part rely upon the use of road oil, which is 
made both from petroleum and from coal tar, being thus dependent upon the adequacy 
of the petroleum-product.3 industry and the coal-products industry. 
