148 GEOLOtlY, 



cending series of rocks, 'fhcir proper place is iimnedialely ab(<ve the 

 Millstone grit. Should lliis stratum be wanting in any particular lo- 

 cality, the coal series will fee foiiud restinj^ upon the rock next below, 

 which is a well characteviJ^cd limestone, by some called Transition or 

 Mountain Limestone, or should this be wanting also, then they would 

 be found resting upon the Old ]\eA Sandstone, which is next below the 

 limestone. 



If the inquiry should here anse, how maj" we with certainty know 

 that the stratum under examination is the Old or the New Red Sand- 

 stone, or that the limestone is the Transition or Mountain, or some one 

 else of the numerous limestone formations, which occur in the great se- 

 ries of strata, &c. ? it may be observed that a little examination and 

 comparison will satisfy us thnt each formation may be readily distin- 

 guished, (1) by its lithological character, that is, by its composition, 

 structure, and appearance ; and (2) by the fossils which it contains; 

 each member of the series having organic remains ditlering, either in 

 whole or in part, from those immediately above or below it. This sec- 

 ond characteristic is even more to be relied on, when the fossils are pre- 

 sent, than the first. The Millstone grit, is however easily recognized 

 by its lithological character alone. It consists of rounded quarlzose 

 fragirients, of various sizes, from that of a walnut down to that of ordi- 

 nary sand, firmly cemented together. 



Now the use which we may make of this information is, that we 

 can by it determine whether, in any particular region, coal may or may 

 not be found. If, for instance, the Millstone grit, or Transition lime- 

 stone, or Old Red sandstone, or any of the rocks, which occur l)elo\v 

 the coal series, be the surface lock, then it is in \'&\\\ to expect coal 

 ihcie, and any search for it would be f"olly. Thus from A to B, as also 

 between C and D, (see figure in No. II of the .Journal of the last month), 

 no coal can be found, because the inferior rocks rise to the surface, and 

 tlie uppermost even of these are washed away from the intervening sum- 

 mits. Hence some of the highest ridges of the Allegheny mountains 

 are destitute of the coal measures, which are to be found both on the 

 East and West of them ; and the whole of the State of New York is 

 alike destitute, the series of strata ascending in passing southward, until 

 the coal is met with on the borders of Pennsylvania. By a proper at- 

 tention to these facts the expenditure of much time, labor and money, 

 in a vain and fruitless search may be avoided. 



But it is by no means certain that coal may be found, even if the 

 higher members of the series be at the surface; for each stratum is not 

 always j)resent in every locality. P'nither starch will be necessary to 



