418 THE EMPIRE OF THE AIR. 



better luck than the others; he flapped his wings vigorously, sinking 

 downward, and just as I believed him to be fairly under way, he struck 

 a post and broke a wing. 



I must own that I was not pleased with my purchase, and there was 

 good reason. To spend good money in conferring liberty on captives,, 

 to rack my brain about them, to carry them nptothe roof of the house,, 

 and then to fail flat, this was hard luck. 



There was still one bird, a forlorn hope. I had got it into my head 

 that I must see this bird in full flight and 1 was determined not to 

 miss my aim this time. 



I reflected a long while; at last an idea struck me, and Inn-e was the 

 result. 



Less than a mile from my farm there was an open tract, naked, bare 

 of grass, flat, smooth as a mirror. It struck me that these conditions 

 were somewhat analogous to the surface of the sea in a calm. 



I carried thither my No. 4, who appeared to be Just as stupid as his 

 three predecessors. 1 set him down on this extended area, and retired 

 to a distance. The creature remained squatted down for a good while, 

 then he turned, with his beak to the wind, and he stretched his wings. 

 Then he showed me that I had reflected to some purpose. 



He started running and beating his wings, which were not hami)ered 

 by any herbage, and ran in this way about 100 yards, carrying his 

 weight less and less upon his feet, and fliuiUy all on his wings, but all 

 the time skimming the ground. At last, with a single bound, catching 

 the wind, he rose some 00 feet, returned towards me, and as he glanced 

 l>y on his way, I thought he said to me, '' Remember hereafter, oh! my 

 preserver, that success in jiight is all based upon speed.'''' 



******* 



Effects of Mass. — Among birds of the same shape and same nuiscular 

 ])ower mere difference of weight produces eftects (juite varied, and 

 yet all of a piece. 



Let us note how a difficult exercise is performed by the eagle, by 

 the falcon, and by the lark, all three being perfectly comparable as t(( 

 their construction. 



The eagle remains motionless in the air, on rigid wings, using only 

 his tail to balance himself; he is as fixed in space as if spiked to the 

 sky. The falcon also remains at a fixed point, but he beats his wings; 

 while the lark cannot perform this maneuver, under the same atmos- 

 pheric conditions, without painful effort, as it is constantly carried 

 away by the wind. 



This law of disproportional aptitude for flight between the smaller 

 and the larger l)irds constantly deceives the eye and confuses the 

 data gathered. An actual example will exhibit the law. 



The (piail, which everybody knows, i'S an especially heavy bird. It 

 flies with meat effort. It is a round ball with two small wings which 



