24 POWER OF VISION. 
eagle has been variously styled “the king of birds,” “the 
royal bird,” “the princely eagle,” and “ Jove’s bird,” while 
so great is his power of vision, that an “eagle eye” has 
become proverbial. 
“ Behold, his eye, 
As bright as is the eagle’s, lightens forth 
Controlling majesty.” 
Richard [I, Act iii. Se. 3. 
The clearness of vision in birds is indeed extraordinary, 
and has been calculated, by the eminent French naturalist 
Lacépéde, to be nine times more extensive than that of 
the farthest-sighted man. The opinion that the eagle 
possessed the power of gazing undazzled at the sun, is 
of great antiquity. Pliny relates that it exposes its 
brood to this test as soon as hatched, to prove if they be 
genuine or not. Chaucer refers to the belief in his 
“ Assemblie of Foules” :— 
“There mighten men the royal egal find, 
That with his sharp look persith the sonne.” 
So also Spenser, in his “ Hymn of Heavenly Beauty,”— 
“ And like the native brood of eagle’s kind, 
On that bright sun of glory fix their eyes.” 
It is not surprising, therefore, that Shakespeare has 
borrowed the idea :— 
