ALTITUDE AND SPEED OF FLIGHT 



The late Herr Gatke, the venerable bird- 

 watcher of Heligoland, had many remarks to 

 ofier on this question. His conviction was that 

 birds on migration travel normally at far greater 

 heights than was usually supposed. He be- 

 lieved that the flocks which come withm our ken, 

 skimmmg the surface of the sea, and stnkmg 

 against our lighthouses, vast as they may be, 

 were none the less merely the contingents which 

 had been checked in their course, and that their 

 travel must be regarded as more or less unsuccess- 

 ful and abortive attempts at migration, the more 

 fortunate voyagers taking a line at a far greater 

 elevation. 



Corroboration of this view is furnished by 

 Mr. F. M. Chapman, the ornithologist at the 

 American Museum, New York. He states 

 that in New Jersey, on the 3rd of Sep- 

 tember, 1887, when making certain observations, 

 he carefully noted 262 birds crossing the moon's 

 face. Of these 233 were computed to be at a 

 height of from 1,500 to 15,000 feet. The re- 

 markable thing in this case was that the lowest 

 birds were seen to be " flymg upward," as if they 

 had risen from the immediate neighbourhood, and 



were seeking the proper elevation at which to 

 continue their flight." Mr. W. E. D. Scott has 

 recorded that on the night of the 19th October, 

 1880, he saw through an astronomical telescope 

 at Princeton, great numbers of birds passing 

 across the face of the moon. Computations 

 showed that these migrants, among which were 

 recognised warblers, finches, woodpeckers, and 

 blackbirds, were travelling at heights varying 

 from one to two miles. A second astronomer, 

 Mr. J. Tennant, has stated that he has seen birds, 

 apparently kites, frequently pass over the sim's 

 face, some of which were in focus with the sun 



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