Aeronautics have changed the whole perspective of life for birds, as they may for us shortly; so it is no surprise to find that birds have, almost with one consent, converted their tails into steering-gear. A commonplace bird, like a sparrow, scarcely requires this except as a brake when in the act of alighting; but to those birds with which flight is an art and an accomplishment, an expansive forked or rounded tail (there are two patents) is indispensable. We have shot almost all the birds of this sort in our own country, and must travel if we would enjoy that enchanting sight--a pair of eagles or a party of kites gone aloft for a sail when the wind is rising, like skaters to a pond when the ice is bearing. For an hour on end, in restful ease or swift joy, they trace ever-varying circles and spirals against the dark storm-cloud, now rising, now falling, turning and reversing, but never once flapping their widespread pinions. How is it done? How does the _Shamrock_ sail? Watch, and you will see. When the wind is behind, each stiff quill at the end of the wing stands out by itself and is caught and driven by the blast; but as the bird turns round to face the gale, they all close up and form a continuous mainsail, close-hauled. And all the while the expanded tail is in play, dipping first at one side and then at the other, and turning the trim craft with easy grace "as the governor listeth." [Illustration: THERE ARE SOME ECCENTRICS, SUCH AS JENNY WREN, WHICH HAVE DESPISED THEIR TAILS.] Besides ground birds, like the quail, there are some eccentrics, such as Jenny wren, which have despised their tails, and there are specialists also which require them for other purposes than flying. The woodpecker's tail is quite useless as a rudder, for he is a woodman and has altered and adapted it for a portable stool to rest against as he plies his axe.