584 The Zoologist — January, 1867. 



flying with speed as undiminished as if high in air, will readily see the 

 aptness of this simile. Again, 



" As swift as swalloiv flies. 



Id. Act iv. Scene 2. 



It is difficult to calculate or limit the speed which can be produced 

 by the effort of a wing's vibration. We may nevertheless ascertain 

 with tolerable accuracy the rate of a bird's flight as follows: — If we 

 note the number of seconds which are occupied by a bird in passing 

 between two fixed points in its line of flight, and measure the distance 

 between these points, we resolve the question to a simple " rule of 

 three" sum, inasmuch as knowing the number of yards flown in a 

 certain number of seconds we can ascertain the distance traversed in 

 3600 seconds, or an hour, and thus obtain the rate of speed per hour, 

 supposing, of course, the speed to be uniform. 



In this way the flight of the common swallow has been computed at 

 90 miles, while that of the swift has been conjectured to be nearly 

 180 miles per hour. 



" True hope is swift and flies with swallow's wings." 



Richard III., Act v. Scene 2. 



The swallow, although one of the earliest, is not always the first of 

 our spring ornaments to appear. There are 



" Daffodils 

 That come before the swallow dares, and take 

 The winds of March with beauty." 



Winter's Tale, Act iv. Scene 3. 



Martin {Hirundo urbica). 



" This guest of summer, 

 The temple-haunting martlet does approve, 

 By his lov'd mansionvy, that the heaven's breath 

 Smells wooingly here; no jutty, frieze, 

 Buttress, nor coigne of vantage but this bird 

 Hath made his pendant bed and procreant cradle. 

 Where they most breed and haunt I have observed 

 The air is delicate." 



Macbeth, Act i. Scene 6. 



Sir Joshua Reynolds was struck with the beauty of this brief 

 colloquy before the Castle of Macbeth, and he observes on it: "This 



