By the Rev. A. C. Smith. 243 
enquiries a little farther; and still bearing in mind that they are 
denizens of the air, and roam at vast distances above our heads, and 
all around us, examine into the senses and faculties with which 
they are endowed. 
In the first place we shall find them fnrnished with unusual 
powers of sight, hearing, and smell, and to this end they are 
supplied with three double organs of sense, viz: eyes, ears, and 
nasal cavities. 
The sight of some, and particularly of the rapacious birds, is so 
acute and piercing, as to enable them to see their prey from an 
enormous height in the air, whence they dash down with astonishing 
swiftness and unerring aim. The vulture sailing in circles at an 
immense altitude can distinguish his prey on the ground, without 
the aid of any other faculty than his eyes, as has been clearly proved 
by experiment: the lordly eagle soaring amid the clouds seems to 
prefer that elevated station, whence to seek some victim on the 
earth, and his wonderful power of vision seldom fails to discover 
the desired object far below: the kestrel hawk, with which all are 
familiar, balances himself in the air at a considerable height, while 
his piercing eyes search the ground below for the mice which 
constitute his food: these are all diurnal birds of prey, and are 
especially noted for the keenness of their vision: but not less 
extraordinary is the eye of the owl, which seeks its prey by twilight, 
and cannot endure the full glare of day: should any accident 
expose him to the light of the sun, he either closes his eyes entirely, 
or defends them with a curtain or blind, which is an internal eyelid, 
and which he can close in an instant. At such times he presents 
but a grotesque and foolish appearance, but see him as he emerges 
from his hollow tree, or the ivy clad ruin in the deepening twilight: 
watch him as he regularly beats the field, and quarters it like a 
pointer; see him suddenly drop upon the unfortunate mouse that 
was hurrying through the grass, and judge what acuteness of vision 
must be there. In the nocturnal species the eyes are usually directed 
forwards, and are brighter, larger, and clearer than those of the 
diurnal birds, and thus from their size, position, and construction 
are admirably calculated for concentrating the dim rays of twilight. 
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