92 THE BIRDS OF HELIGOLAND 



and Cinclus Pallasi was identified at a distance of from four to six 

 paces on the 31st of December, all of which instances afford further 

 strong proofs of an exceptionally powerful mass-migration from 

 east to west. The weather, moreover, was highly favourable to a 

 jnovement of this kind, or, more correctly speaking, was its originat- 

 ing cause, for, as has been already stated, easterly, and more 

 particularly south-easterly, winds predominated during the whole 

 time of this migration. 



I had long entertained the opinion, I might almost say con- 

 viction, that the calms and east winds prevailing here during these 

 powerful migrations from the far East extended to the remote parts 

 of Eastern Asia. For a long time, however, I was unable to assure 

 myself of the truth of this conjecture. I have, however, quite re- 

 cently been enabled to do so through the extraordinary kmdness and 

 assistance of Professor Neumayer, director of the Marine Observa- 

 tory at Hamburg, who has supplied me with extracts from the 

 records of the meteorological observations conducted on a large 

 scale at the instance of the Russsian Government, not only through 

 the European but also the Asiatic portions of that empire. I repro- 

 duce these data within a brief comjjass, and in a form best adapted 

 to the object in view ; calling special attention to the fact that, 

 although only twelve points of the compass, from north-east 

 through east to south, are adduced as favourable to the migratory 

 movement in question, twenty points from south through west to 

 north-east being consequently opposed to it, the result is, neverthe- 

 less, in all pertinent cases an exceedingly favourable one. 



The year 1879 also was distinguished, both during the spring 

 and autumn migrations, by very numerous occurrences of eastern 

 and south-eastern species. This is the last year for which I have 

 meteorological observations from Russia at my disposal ; these, 

 however, extend over nine stations from 21" to 82" 47' longitude 

 east of Greenwich. (See table, p. 95.) It is hardly necessary to 

 mention that easterly, and more particularly south-easterly, winds 

 and calms prevailed in Heligoland during both periods of migra- 

 tion, and the same was the case along the whole track of migra- 

 tion from here to Semipalatinsk and Barnaoul, beyond which the 

 observations do not at that time seem to have been extended. 

 The total results from these nine localities for the year in question 

 gave for the months of May and June 319 days of favovu-able, 

 as against 230 days of unfavourable travelling weather, while 

 for the months of September and October the relations were 

 3251 favourable, as against 162J unfavourable days. For the year 

 1847 already referred to, data from one place only have come to 

 hand, viz., Lugau, south-east of iloscow; during the months of 



