518 W. H. HARRIS ON THE EMISSION OF MUSICAL NOTES 



(3) That there are from twenty-three to twenty-five pleats or 

 folds in each vocal organ, and not nine as distinctly stated. 



(4) That it is a very delicate and pliable membrane that is 

 thus folded, and not " horny laminae '" as described. 



Hovering. 



I approach the subject of hovering with great trepidation, for 

 I must candidly admit that I know nothing about it. For the 

 life of me I could not state in correct terms the mechanical 

 theories of either flight or hovering. In my perplexity I sought 

 the aid of a friend who really knows a thing or two, but from 

 him no assistance could I obtain. He, however, consoled me with 

 the assurance that my complete ignorance of the subject was in 

 reality my special qualification for dealing with it, as possessing 

 such vacuity I must be free from prejudice, and that therefore 

 I was the proper person to discourse upon this very interesting 

 subject. This was comforting, but scarcely reassuring ; at any 

 rate, it appeared to be " up-to-date." 



While at the seaside last summer I was seated near the edge 

 of a cliflf, the face of which was nearly vertical. A moderately 

 strong but steady breeze was blowing, and poised above me at an 

 altitude of from seventy to eighty feet was a sea-gull. With the aid 

 of my glass I watched this bird for half an hour, but no movement 

 of its outspread \vings could T perceive, save alone, occasionally, 

 a slight change of inclination, which enabled the bird to regain 

 its original position, from which it would be quietly drifted inland 

 by the current of air in which it floated. I walked away half a 

 mile, occasionally turning to look at the bird ; returned, and 

 again sat down for a w^iile, and finally left it still poised. It 

 seemed a perfect illustration of the story told by an American 

 traveller with regard to one district he had visited where every- 

 thing was petrified — the trees, the beasts, even the birds were 

 still suspended in the air over that district. On the expression of 

 a doubt as to the latter statement, he calmly assured his audience 

 that in that region even gravity was petrified. But this is a 

 digression. 



On reflection I found that the sea-gull gave me no more 

 assistance than had my unfeathered friend. Let us think for 

 a moment. The wind, striking the almost vertical face of the 

 clifl", is deflected upward with considerable velocity ; as this force 

 diminishes it again resumes its original course and passes inland. 

 In this upward current the gull, with its outspread wings, as 



