28 W. A. E. Ussher — Historical Geology of Cornwall. 



worthy of credence, especially when the accounts are corroborated 

 by independent writers. 



It has ever been the characteristic of the ignorant and unin- 

 quiring peasantry to ascribe the occurrence of great boulders of 

 rock dissimilar to any in the neighbourhood, the fantastic shape, 

 so frequently effected by weathering in rocks of unequal durability 

 and such-like remarkable objects, to the agency of fabulous beings 

 endowed with enormous strength and gigantic proportions ; and so 

 names are given to phenomena of unusual occurrence, and are 

 retained by a less credulous posterity even when the legends which 

 suggested them have almost entirely passed away. Many such names 

 are to be met with in Cornwall. 



Again, traditions of a more extensive coast-line, of lands now 

 swept away, have been handed down, doubtless magnifying the 

 extent of the ancient land, as the account passed through succeeding 

 generations. 



Our familiarity with the causes producing such phenomena as 

 earthquakes, comets, eclipses, and the like, however seldom some 

 of them have been experienced in a lifetime, renders the obser- 

 vations of the present age more accurate and less liable to exaggera- 

 tion than those of preceding centuries, when anything of infrequent 

 occurrence in the experienced operations of nature was regarded 

 as cataclysmal, resulting from direct interposition in an unvarying 

 state of things. The rapid advance and more general cultivation of 

 scientific research, no longer fettered by ignorance and superstition, 

 embraces in an ever-extending chain of cause and effect phenomena 

 which our ancestors regarded as supernatural. 



It is however curious to note how some amongst the ancients, 

 by the acuteness of their perceptions, grasped an occasional scientific 

 truth which has been corroborated in the present day. Thus, it is 

 remarkable that Ovid, Pythagoras, Pliny, and Aristotle should have 

 believed the sea to be less changeable than the land. 1 Strabo, in 

 opposing the opinions of Eratosthenes and Xanthus as to the cause 

 of shells being found at great elevations and distances from the 

 sea, says : "It is not because the lands covered by the seas were 

 originally at different altitudes that the waters have arisen or 

 subsided or receded from some parts and inundated others. But 

 the reason is that the same land is sometimes raised up or depressed, 

 so that it either overflows or returns to its own place again. We 

 must thei'efore ascribe the cause to the ground, either to that ground 

 which is under the sea or to that which becomes flooded by it, but 

 rather to that which lies beneath the sea, for this is more movable." 



The historical evidence may be classified under three heads : — 



Firstly, accounts of unusual disturbances of the sea by contem- 

 porary observers. 



Secondly, records of disastrous inundations preserved in old 

 chronicles. 



Thirdly, traditions of the Lyonesse and probable references of the 

 ancient geographers and historians to the Scilly Isles. 



1 Stoddart, Proc. Brist. Nat. Soc. for 1870, vol. v. p. 43. 



