98 THE BIRDS OF HELIGOLAND 



within the last ten years. All these changes can only be attributed 

 to alterations in the conditions of temperature. The average 

 annual temperature may have remained the same ; but, whereas 

 the winters are now not particularly cold, the summers are in a 

 corresponding degree less warm. Sultry summer evenings are no 

 longer known here at all, and even when a day of summer happens 

 to be fine and warm, and apparently heralding a good catch of 

 moths, it is sure to be followed by a cool, if not actually cold 

 evening, with light north winds. 



This change in wind and weather records itself on this island 

 in another very striking manner. The little sand island or dune 

 belonging to Heligoland has, in the course of years, lost consider- 

 ably in extent through the agency of high tides raised by storms, 

 the bases of the sandhills having been undermined by the action 

 of the waves, and the sand subsequently thrown down has been 

 washed away by the tide. 



Until about the beginning of the sixties this process of erosion 

 used to take place in severe north-western storms on the north 

 side of Sandy Island. No substantial diminution of land occurred 

 in any other part, least of all on the south side. Since that time, 

 however, matters have completely changed, the sandhills and 

 foreshore being now uninterruptedly torn away by the sea on the 

 south side of the dune, while simultaneously, on the north side, the 

 shore and sandhills have been considerably added to. These changes 

 are still in progress in the present year of 1890. Processes of this 

 kind show that since the beginning of the sixties a complete 

 change must have taken place in the prevalent direction of the 

 wind, seeing that the entirely different effects noted above could 

 only have resulted in consequence of a corresponding change in 

 the causes which produced them. So much, at any rate, is certain, 

 that during the period mentioned there has been no occurrence of 

 powerful tides raised by north-westerly gales, such as were frequent 

 here formerly; in fact, heavy storms from the north-west have been 

 in general among exceptional and isolated phenomena. 



The frequency of the earlier occurrences of such hurricane-like 

 storms has, indeed, given rise to the application of separate names 

 to them in regard to the manner and mode of their development. 

 Thus a moderate west wind, accompanied by heavy rain, which 

 steadily veered round to the south with increasing force and finally 

 developed into a violent south wind, was known by the name of 

 App-Krumper. This, after a calm of shorter or longer duration, 

 was usually succeeded by the sudden eruption of an extremely 

 violent storm from the north-west, to which the name Utt- 

 Stjutter was applied. These expressions may perhaps be rendered 



