4 INTRODUCTION. 



Nor can the natural history of birds be regarded as merely 

 a subject of intellectual enjoyment, high as it ranks in this 

 respect ; for the elements of much practical science, and the 

 foundations of many of our most useful arts, may be traced 

 in the economy of birds. The doctrine of motion is one of 

 the most useful branches of knowledge, and nowhere can that 

 be studied so easily, or under so many varieties and modifica- 

 tions, as in the feathered tribes. The birds move through 

 the air in all directions, upwards, downwards, and horizon- 

 tally : they run upon the earth over all sorts of surfaces, on 

 firm ground, over quagmire, or on long grass ; and some of 

 them, aided by the action of their wings, walk the waters, 

 and row themselves by their feet, while the weight of the 

 body is suspended on the air. They swim, they dive, they 

 run along on the bottom in the shallows, or through the 

 water in the deeps; and, in short, they perform every species 

 and almost every rate of motion that can be imagined, from 

 a velocity which surpasses the hurricane in the utmost of its 

 fury, to gentle gliding, barely perceptible by the eye. All 

 these varied motions are performed by means of organs 

 adapted so much more nicely to their purposes than even 

 our finest mechanical contrivances, that they may be said to 

 differ from these in kind more than in degree ; and, though 

 we may take many useful hints from them, they are far 

 above our imitation. That the same bird should be able, 

 without any change of substance, and by the action of its 

 mechanical structure alone, to ascend and descend at pleasure, 

 either in air or in water, is in itself a subject well worthy of 

 the most profound investigation. 



Nor are the uses of the birds, not merely in wild nature 

 but in conjunction with man as he cultivates the garden and 

 the field, less worthy of being observed and admired. We, 

 in our ignorance, often regard them as pests, and as such 

 destroy them in the most assiduous manner, deeming every 

 e athered creature which we deprive of life as so much cer- 



