Azotes on Pctrolcnui in California. — Clay pole. 157 
As might be inferred from a map the strike of the CaH- 
fornian anticlines is usually northwest and southeast or nearly 
so. Many of their ridges though of so recent formation have 
been eroded and consequently their oil, or at least its more 
volatile portion, has escaped leaving either no residue or only 
the "brea' or asphalt to indicate its former presence. 
These facts supply a rational base for the belief that when 
the strata are deeply covered, numerous yet unknown oil-fields 
will be found that at present lie below the depth explored and 
can only be detected by systematic geological study and judi- 
cious exploration with the drill. The greater degree of erosion 
in the northern counties is also the probable explanation of the 
present limitation of the oil-fields to the south of the state. 
At the same time we must recollect that holes more than 
1,000 or 1,500 feet in depth are almost unknown. 
Nature and use of the oil. Probability scarcely indicates 
that Californian petroleum can compete with the Pennsylvanian 
product as a source of illuminating oil. It more resembles the 
Russian and the Ohio and Indiana petroleum in this respect. 
But as already mentioned its great value to the State will be 
its fuel value. Where the lighter grades are produced the 
illuminating ingredients will doubtless be distilled ofif and the 
residue will then be of equal or greater value as fuel. This is 
already done. The heavy oils will however find their value 
and use in taking the place of coal and supplying heat in many 
cases where the cost of coal would be an insuperable barrier. 
The lower price of oil, its transportation by pipes, its supply 
to the furnace by gravity, the absence or slightness of the 
smoke and ash, the avoidance of stoking, all these are advan- 
tages which cannot be over estimated in a comparison of the 
two fuels. To say that the exploitation of petroleum has 
given California an open door where before it seemed hope- 
lessly closed, is not an exaggeration of the fact or too roseate 
a picture of the prospect. 
The Future. It is too soon of course to prophesy the 
future by predicting the duration of the supply. But in spite 
of all anticipation of a speedy failure, the eastern yield has 
not yet run out. It has continued beyond most calculations or 
prognostications made forty years ago and there is even now 
reasonable ground for expecting early exhaustion. Nor is 
