PREFACE 



These Studies are offered as contributions to what 

 has ever been an attractive branch of the science of 

 Ornithology. They are the result of many years' per- 

 sonal observations and researches, during" which excep- 

 tional opportunities have been afforded me for acquiring 

 special knowledge of the subject. 



In the year 1880 it was my good fortune to become 

 the intimate friend of the late John Cordeaux, who first 

 inspired me with an interest in bird-migration that has 

 never waned. In 1883 I was elected a member of the 

 British Association Committee on the Migration of 

 Birds as observed on the British and Irish Coasts. On 

 the completion of the investigations it was my privilege 

 to be entrusted with the preparation of the Reports, 

 five in number, embodying the results of that great 

 enquiry — a task which was finally accomplished in 1903. 



The preparation of these Digests revealed the fact 

 that, vast though the data were, much desirable informa- 

 tion was still lacking. This led me to undertake a series 

 of special investigations with a view of contributing to 

 our knowledge on these moot points, and in the hope of 

 adding to the lore of the subject of Bird-Migration 

 generally. A residence of forty - seven weeks in light- 

 houses and in a lightship, and fourteen weeks spent 



