BUCKMAN — SEARCH FOR COAL. 
131 
same fact applies to the rock above, the roof of the coal. This, in 
proper order, will be the New Red Sandstone ; and though this rock 
may be absent, and newer deposits take its place, still the true coal 
deposits * are not found above the New E.ed Sandstone ; so that in 
reality the table of strata, as now understood, represents rocks of dif- 
ferent ages, each having its own established and relative position. 
From these considerations, then, it will be seen that it is often 
easier to decide where coal is not than where it is — for as rocks of all 
ages rise to the surface, or " crop out," as the miner terms it, we may, 
in such case, readily determine, even in a coal country, at least a Hnii ^ 
to our search in one direction. 
"W. Section 1. E. 
1. Silurian. 2. Old Red Sandstone. 3. Mountain Limestone. 4. Coal. 6. New Red Sandstone. 
6. Lias. 7. Oolites. 
Here we see that, as older beds crop out to the west, from beneath 
the coal measures, it would be in vain to seek for coal in that direc- 
tion ; so, in like manner, any well-done geological map of a district or 
a country would give us distinct information on this point — for 
wherever beds older than coal form the substratum it would be utter 
folly to mine in them with the hope of finding coal. It was precisely 
upon these principles that the geological surveyors of the state of 
New York, North America, decided that this large State was without 
coal, and thus put a stop to the wildest speculations, both theoretical 
and practical, upon the subject, which had been the causes of so many 
miserable failures. 
In our own country how many trials have been made for coal in 
rocks older than that deposit? In that magnificent work, "The 
Silurian System," by Sir R. I. Murchison, accounts are given of no 
less than eight attempts to reach coal from Silurian rocks — sanguine 
speculators being deceived by dark-coloured shales, a slight deposit of 
carburet of iron, plumbago, or, as in one instance, a little real 
anthracite. One of these is worth quoting : — 
* Of course we are aware of coal deposits in the Oolitic and even in the Ter- 
tiary rocks, but these are usually unproductive. 
