Correspondence — Mr. W. H. Penning. 



283 



dnced on a smaller scale in the G-eological Magazine. A full-sized 

 copy, on a scale of 4 miles to an inch, has been deposited with the 

 Geological Society of London. 



Scale 10 miles to 1 inch. 



Map of Helgelandt at three different periods reduced from oae said to have been 

 " copied from an old ma,p in the possession of the Governor of Helgelandt." 



A.D. 800, when l20 miles in circumference. 



1300, 



45 



,, 1649, Since this time it has been rapidly diminishing, the smaller Island 

 having entirely disappeared, and the larger being considerably 

 reduced. 



On looking at the map, one cannot fail to notice the rapidity with 

 which the island formerly disappeared, an area of something like 

 500 square miles having been removed in a period of 500 years. In 

 the following 350 years, 100 miles only were reduced, leaving an 

 area of 4 miles, which since 1640 has diminished to a mere speck 

 less than -^ of a mile in superficial extent. 



There are traditions that the island was suddenly reduced by incur- 

 sions of the sea, but these probably are true as regards comparatively 

 small portions only. The erosion has doubless been constant and 

 gradual, the portion which still remains having been from some cause 

 able the longest to resist the agencies of denudation. 



