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ON SOME TBAILS AND HOLES FOUND IN ROCKS 



history of the world, and with impressions on rocks which 

 have outlived the decay of centuries, but which were, in their 

 origin, of no more apparent stability than these marks in the 

 sand, or than our own foot-prints. When a surface of sand- 

 stone rock is uncovered, it very frequently exhibits markings 

 of a nature precisely similar to what we every day meet 

 with on the sandy shore. There is the ripple-mark, defined 

 with equal regularity and sharpness — we see where every 

 wavelet of the antediluvian ocean did its work ; — there are the 

 sinuous roads, cut out by the antediluvian molluscs now visi- 

 ble in relief, by the mud which has silted into them ; — the 

 worm-like heaps of sand, which mark the position of the 

 worm, or of the testaceous mollusc, are equally obvious in the 

 sandstone, and on the recent shore ; — the very rain-drops 

 which impressed the sandy surface thousands of years ago 

 have left their record on the surface of the rock. When we 

 see all these appearances on the newly turned up rock, and 

 find similar markings on the flat sands of the sea, it is impos- 

 sible to avoid connecting the two observations, and admitting 

 that in what passes under our eyes as a daily occurrence on the 

 sands, we find the explanation of the geological phenomenon. 

 The sandstone rock, hard as it now may be, was once a beach, 

 as impressible as that in which we may now be leaving our 

 foot-prints. And though, in thousands of cases, these foot- 

 prints will be swept away by the next flow of the water, it 

 may so happen that they will remain. And it is a wonderful 

 circumstance that all trace of soriie of the gigantic animals 

 which once inhabited the world has perished from the know- 

 ledge of mankind, save only the track of their foot-prints 

 left in what was then adhesive mud, but which successive ages 

 have converted into hard stone. If Robinson Crusoe was 

 powerfully affected by meeting with the naked human foot- 

 print in the sand, what a crowd of thoughts are awakened by 

 discovering, in the hard rock, this only evidence of a gigantic 

 animal. A true poet has said, — 



