UPON ROCKS OF THE NEW YORK SYSTEM. 429 



al to suppose that this sandstone deposit was at that time a long, 

 level, or nearly level sandy beach, like some upon our present sea- 

 shore, and that the tide ebbed and flowed over this to a great dis- 

 tance. It may have been so nearly level, that a rise of a few feet 

 perpendicular would cause the water to flow over many rods in 

 breadth. 



If the condition could have been that which would cause the 

 hardening of this surface while the tide was out, the return of the 

 wave with a fresh deposit would not obliterate the old lines, but 

 preserve them, and in this way every fresh deposition would pre- 

 serve the former lines, and in turn be marked by similar lines 

 itself. 



It is very evident, that the depositions of this period were A^ery 

 thin, as we find layers separated by divisional planes, and often 

 some little foreign matter between each, which are less than one 

 eighth of an inch thick. All these laminae, however, are not 

 marked by wave ^ lines; some indicate a quiet and undis- 

 turbed condition of the water, as if the tide ebbed and flowed 

 without wind, as was doubtless the case at times. We have thus 

 conclusive proof of the state of this ancient ocean in regard to 

 wind and tides, and that, like our present ocean and its bays, it 

 was sometimes moved by winds, and at other times quiet and 

 unruffled. 



Difficult as it may be to conceive of a condition capable of 

 preserving such minute traces of former operations as these wave 

 lines, still we know that marks, equally liable to be erased, have 

 been preserved through successive deposits, under what may be 

 considered precisely similar circumstances, in great numbers, and 

 over a great extent of country. These are the footsteps of Batra- 

 chian animals in Germany and England, and of bu'ds in Ameri- 

 ca, which are preserved through successive strata in the new red 

 sandstone, with almost the same integrity as recent footsteps in 

 clay, or the maker's name upon a burned brick. 



The discovery of bones leaves no doubt of the origin of the 

 footsteps in England and Germany. In -the Connecticut River 

 VaUey, Prof. Hitchcock has discovered, extending through suc- 

 cessive strata, the footsteps of birds ; these, too, minute as many 

 of them are, are still preserved in all their integrity ; so much so, 



