ON ERRATIC BLOCKS. 63 



gravel which had entered would be left behind, to 

 give additional width to that part of the cavity 

 that had already been formed. The breach in the 

 rock would, at length, became so large that boulders 

 as well as gravel would be dashed in by the waves, 

 which, during their continued action, would excavate 

 a cavern, the form of which would be that of a 

 hollow sphere. 



ON ERRATIC BLOCKS. 



96. It would appear that the theory which Sir 

 Charles Lyell has promulgated with the view to 

 account for the transport of erratic blocks namely, 

 by the agency of icebergs has not been fully 

 adopted by geologists, as we still read of currents of 

 water and waves of translation as the agents em- 

 ployed in the transport of those blocks. 



97- When erratic blocks have been removed to a 

 distance remote from the parent rock, and have, not- 

 withstanding, preserved their angular parts sharp 

 and entire, does not this argue that those massive 

 fragments have been carried to the place that they 

 now occupy, and there deposited? that as their 

 edges, during their transport, had not been subjected 

 to attrition, therefore, neither currents of water nor 

 waves of translation were the agents by which those 



