1 88 Bird Comrades 



Even in this day of scientific research and astuteness, it 

 must not be supposed that everything about the mechan- 

 ics of avicular flight is understood. We may readily 

 comprehend how a bird, without fluttering its wings, can 

 poise in the air ; but how can it move forward or in a circle, 

 and even mount upward, without a visible movement of 

 a pinion? And this some birds are able to do without 

 reference to the direction of the ethereal currents. -That, 

 I venture to say, is still a mystery. It almost seems as 

 if some of the masters of aerial navigation in the bird 

 world were gifted with the ability to propel themselves 

 forward by a mere act of volition. 



An interesting article on the subject of bird flight 

 appeared not long ago in one of the foremost periodicals 

 of the country, a part of which is here quoted to show 

 what a puzzling problem we have before us: 



' Recent developments in aerial navigation have 

 renewed interest in the comparative study of the mechan- 

 ical principles involved in the flying of birds. There is 

 one exceedingly puzzling law in regard to birds and all 

 flying creatures, the solution of which may work far- 

 reaching influences in the construction of flying craft. 



: 'This law, which has thus far perplexed scientists, is 

 that the heavier and bigger the bird or insect, the less 

 relative wing area is required for its support. Thus the 

 area of wing surface of a gnat is forty-nine units of area 

 to every one of weight. In graphic contrast to that, a 

 condor (Sarcorhamphus gryphns) which weighed 16.52 

 pounds had a wing surface of 9.80 square feet. In other 



