INTRODUCTION. 
Ixxvii 
it falls with amazing velocity, with its head in a perpendicular position 
throughout the whole of its descent, because it seizes its food with its bill. 
The ^yagtail moves in curves, resembling the undulation of a wave; but 
the Kingfisher and y'^aterousel, by a swift, straight, yet almost imper- 
ceptible and noiseless motion of the wings, dart along just above the sur- 
face of the water ; but the Partridge, creating a constant, loud, and whir- 
ring noise, flies with scarce less speed, and in a similar manner. The 
flight of the Sw^allow is a natural barometer, when it moves rapidly round 
and high in the atmosphere, it indicates a settled state of fair weather; and 
when it skirts silently along, just above the surface of the earth, it warns 
us of the approacli of rain. The Swift, of all English birds the most 
renowned for celerity, glides round in circles, with one wing depressed and 
the other elevated, both waved with such instantaneous rapidity, that the 
eye can scarcely perceive the motion ; on the other hand, the Skylark mounts 
into the clouds, by a continual and quickly-repeated agitation of its wings, 
and descends toward the ground by a constant fluttering, or darts with 
the rapidity of an arrow toward the earth, in an oblique line. The Tit- 
lark and the Rocklark, like all the Lark genus, ascend by repeated agita- 
tion of their pinions, but descend with their wings in a quiescent state, 
and forming right angles, their tails elevated and their feet hanging down ; 
while the Woodlark, balancing itself in the air, pours forth its cheering 
strains. The flight of the Starling is swift, easy, and little laboured, and, 
of all the Thrush genus, wild, irregular, and desultory. There is not 
among birds a single species that travels the vast expanse of Heaven, but 
which has some particular mode in its flight, by which it may be distin- 
guished from individuals of a different race ; and a slight examination of 
the actions of the feathered creation, will educe the conclusion, that swift- 
ness does not wholly depend on expansion of wing. The short-winged 
Kingfisher, in its aerial motions, is marked for celerity ; and the broad- 
winged Buzzard, for its tardy movements. Birds, which have small wings, 
have thick and close-connected coverts, which greatly assist their flight ; 
and on the whole it may be observed, that strength of the pectoral 
