THE FEATHERS. 65 



Of a feather's lightness, we may form some idea when we 

 find that the largest quill of a Golden Eagle weighs only 

 sixty-five grains, and that seven such quills do not weigh 

 more than a copper penny-piece ; that the feathers of a 

 common Fowl which weighs thirty-seven ounces, weigh only 

 three ounces ; and that the entire plumage of an Owl weighs 

 only one ounce and a half. Meant as they are, some for 

 covering and some for strength, we shall find them, on 

 examination, very differently put together. The light downy 

 part, when examined through a microscope, will be found to 

 bear little resemblance to the flat part or blade of the quill. 

 If it were not so, a bird would scarcely be able to fly at all ; 

 for when the flat of the wing was pressed down, the air 

 would pass through it, and yield no resistance. The fibres 

 of the downy part, we see, have little connexion with each 

 other ; they have short and loose side shoots, just sufficient 

 to mat them together when pressed close to the skin ; 

 whereas, the side shoots of the quill-feather hook and grapple 

 with one another, so as to make one firm and united surface. 

 Some idea of this may be formed from the annexed figures, 

 the second of which represents a piece of the finest down 

 magnified. 



But others there are, much stronger and stiffer than the 

 wing quill-feathers, as those, for instance, forming the tails 

 of the Woodpecker tribe. And the reason would be evident 

 to any person who watched a Woodpecker on the stem of a 

 tree feeding. Its food consists of grubs, usually concealed 

 in the wood. In order to get them, he must therefore 

 remain fixed on the bark, and make a hole with his beak, a 

 tedious, if not an impracticable operation, were it not for the, 

 wiry stiffness of the tail-feathers, which press against the 

 tree, and act like an additional limb. The tail, however, has 

 another use, applicable more or less to all birds ; it is to 

 them, what a rudder is to a boat, and in many cases acts 

 like a third wing. If we look at a Hawk hovering in the 

 air, when he remains in one spot we shall see that the 

 tail is spread out like a fan, and is in a constant state of 



