PETROLEUM. 
53 
current wasteful use of the limited petroleum resource. For that 
purpose an effective and adequate development of oil shale must start 
somewhat in advance of the wave of need that would normally dic- 
tate the launching of this leaner resource. That wave is already def- 
initely in sight ; the question is merely whether we will wait until it 
breaks or now prepare for the force of the impact so as to ease it off. 
It need scarcely be emphasized that any action directed toward the 
tying up of the oil-shale reserves, pending a determination of policy 
regarding their disposition, would be disastrous. The American pub- 
lic is probably sufficiently aware of the irretrievable harm wrought 
by this course of action in regard to certain other less vital resources, 
under the influence of the wave of so-called conservation that swept 
over the country a decade ago, to countenance a repetition of such 
temporizing action. 
DEVELOPMENT OP SUBSTITUTES. 
Even with the most efficient use of the remaining supply of petro- 
leum, and an appropriate development of shale oil in prospect, the 
petroleum situation can be additionally improved by a progressive 
utilization of substitutes for gasoline and fuel oil, so as to give better 
economic balance by relieving the products upon which fall the 
heaviest demands. Two substances, benzol and alcohol, are suitable 
for helping gasoline, and offer the advantage of a record of successful 
use in motor engines in Europe prior to the war, and of a marked ex- 
tension of utilization there under the rigorous conditions of the pres- 
ent conflict, while coal and hydroelectricity may be brought to the 
aid of fuel oil . 1 
Benzol is a light liquid, somewhat similar to gasoline in character, 
obtained at present from the by-product coke oven. The production 
of benzol in the United States is at present small, owing to the fact 
that only about a twelfth of the bituminous coal mined is treated 
for the recovery of by-products. The full utilization of benzol there- 
fore must go hand in hand with the development of methods, as out- 
lined in a previous paper of this series , 2 whereby coal will be made to 
yield a complete measure of usefulness; indeed, the proper utilization 
of coal demands a market for benzol as a motor fuel, while the proper 
shaping of the petroleum resource permits and needs the coming in 
of benzol as an alternate for gasoline. Thus once more appears an 
example of how closely the various elements of the fuel situation are 
connected. 
1 Recent work on castor oil production gives some indication that this organic product 
may come to be a significant source of motor fuel. 
2 Coal : The resource and its full utilization, Bulletin 102, part 4, this series. See 
especially pp. 10-13. 
