238 LIGHT SCIENCE FOR LEISURE HOURS. 



Grind of the Navir, is widened every winter by the 

 overwhelming surge that, finding a passage through 

 it, separates large stones from? its sides, and forces 

 them to a distance of no less than 180 feet. In two 

 or three spots, the fragments which have been de- 

 tached are brought together in immense heaps, that 

 appear as an accumulation of cubical masses, the prod- 

 uct of some quarry." 



Let us next turn to a portion of the coast-line of 

 Great Britain which is neither defended, on the one 

 hand, by barriers of rock, nor attacked, on the other, 

 by the full fury of the Atlantic currents. Along the 

 whole coast of Yorkshire, we find evidences of a con- 

 tinual process of dilapidation. Between the projecting 

 headland of Flamborough and Spurn Point (the coast 

 of Holderness), the waste is particularly rapid. Many 

 spots, which are now mere sand-banks, are marked 

 in the old maps of Yorkshire as the sites of ancient 

 towns and villages. Speaking of Hyde (one of these), 

 Pennant says : " Only the tradition is left of this 

 town." Owthorne and its church have been for the most 

 part destroyed, as also Auburn, Hartburn, and Kilnsea. 

 Mr. Phillips, in his " Geology of Yorkshire," states 

 that not unreasonable fears are entertained that, at 

 some future time, Spurn Point itself will become an 

 island, or be wholly washed away, and then the ocean, 

 entering into the estuary of the Humber, will cause 

 great devastation. Pennant states that " several places, 



