GEOGRAPHICAL ASPECTS 77 



observed at these floating observatories, and that the 

 migrants traversing the southern half of the east coast 

 of England, do so after arrival on its northern section. 

 In this connection evidence of a particularly important 

 nature is afforded by the records kept at Outer Dowsing 

 lightship, which is anchored some 38 miles off the 

 mouth of the Humber. Here these great move- 

 ments ace not observed : a fact which indicates that the 

 migrants pass to the northward and westward of this 

 vessel in their journeys across the North Sea. As 

 regards northern limits for their arrival from and 

 departure to Scandinavia, our knowledge has been 

 greatly added to by recent investigations, which clearly 

 demonstrate that the great majority of the species travel 

 in considerable numbers via the Shetland Isles. All 

 the movements do not cover the extensive stretch 

 of coast-line indicated, but not unfrequently this is 

 the case. Nor must it be supposed that all of the 

 individuals of the species observed in Orkney and 

 Shetland visit these islands on their journeys to and 

 from the Continent ; though many do so, the majority 

 of them cross and recross the North Sea at points 

 further south on our eastern sea-board. 



Fair Isle, lying midway between the Orkney and 

 Shetland groups, has proved to be the most remarkable 

 station for the visits of birds of passage at both seasons, 

 and its record is not surpassed by any other locality 

 in the British Isles, and is only equalled by that of 

 Heligoland. The results of several years' investigations, 

 carried out by myself at this small and remote isle, will 

 form the subject of one of the subsequent studies. 



West Coast of Britain and the Irish Coasts. — These 

 sections of our coast-line are also traversed by great 



