As has been already stated, there is perhaps nothing more wonderful in nature than the power of flight, and no subject which yields such startling facts upon investigation. "The way of an eagle in the air" is one of those things of which Solomon expressed himself ignorant; and there is something truly marvellous in the mechanism which controls the scythe-like sweep of wings peculiar to most birds of prey. The noblest of these, the peregrine, has been seen flying over mid-Atlantic; and Henry IV., King of France, had a falcon which escaped from Fontainebleau, and in twenty-four hours after was found in Malta, a space computed to be not less than 1,350 miles, a velocity equal to fifty-six miles an hour, supposing the hawk to have been on the wing the whole time. Indeed, in Montagu's opinion, the rapidity with which hawks and other birds occasionally fly is probably not less than at the rate of a hundred and fifty miles an hour, when either pursued or pursuing. The speed of flight of the peregrine cited above is about that of our best trained pigeons; and it may here be remarked that the flight of these two (otherwise dissimilar) birds very much resembles each other. The beautiful swallow-tailed kite has accomplished the feat of flying across the whole Atlantic Ocean, which is hardly to be wondered at seeing its vast powers of flight. Lieuwenholk relates an exciting chase which he saw in a menagerie about one hundred feet long between a swallow and a dragon-fly (Mordella). The insect flew with incredible speed, and wheeled with such address that the swallow, notwithstanding its utmost efforts, completely failed to overtake and capture it. The best speed of a railway train is only a little more than half the velocity of the golden eagle, the flight of which often attains to the rate of one hundred and forty miles an hour. Of all birds, the condor mounts highest into the atmosphere. Humboldt describes the flight of this bird in the Andes to be at least twenty thousand feet above the level of the sea. Upon one occasion a falcon was observed to cut a snipe right in two, with such strength and speed did it cut down its prey. Sparrow-hawks and merlins have not unfrequently been known to crash through thick plate-glass windows when in pursuit of prey, or at caged birds.
Of all British birds, none is so beautiful or so secluded in its habits as the kingfisher. Its presence is peculiarly in keeping with the rapid rocky trout streams which it loves to haunt. Its low, arrow-like flight, as it darts like a streak of azure, green, and gold, is familiar to every angler. He hears it far down stream; it comes under the old ivied bridge, passes like a flash, and is gone—how quickly the following will show. Mr. George Rooper, the well-known Biographer of the Salmon, was travelling on the Great Western Railway, which between Pangbourne and Reading runs parallel with, and close to, the Thames. As the train approached the river a kingfisher started from the bank and flew along the river for nearly a mile. Mr. Rooper watched it the whole distance, and its relative position with the window never varied a yard; the bird flying at exactly the same pace as that at which the train travelled, and which the observer had just previously ascertained to be fifty-five miles an hour. This is about half the speed at which the eider-duck flies, as, when fairly on the wing, it makes upwards of one hundred and twenty miles an hour. The rapidity with which all birds of the plover kind fly is well known, and a "trip" of golden plover have been seen midway between Hawaii and the mainland. An officer in Donald Currie's line recently brought home with him a specimen of the St. Helena waxbill which he caught when on watch on the bridge of the Grantully Castle. At the time the nearest land was distant a thousand miles, and the little captive was so distressed that it quietly allowed the officer to capture it.
It has been computed that a red-throated diver swims about four and a half miles on the surface of the water, and between six and seven beneath the surface per hour. Macgillivray states that upon one occasion he watched a flock of red-breasted mergansers pursuing sand eels, when the birds seemed to move under the water with almost as much velocity as in the air, and often rose to breathe at a distance of two hundred yards from the spot at which they had dived. To show to what depth this bird flies beneath the water it may be mentioned that one was caught in a net at thirty fathoms; while a shag, or green cormorant, has been caught in a crab pot fixed at twenty fathoms below the surface; and guillemots literally fly under water without even using their feet. As bearing directly on the interesting subject of flight under water the case of another of the divers may be mentioned. It has been said that one of the strong and original strokes of nature was when she made the "loon," a bird which represents the wildness and solitariness of the wildest and most solitary spots. It dives with such marvellous quickness that the shot of the gunner gets there just in time to cut across a circle of descending tail feathers and a couple of little jets of water flung upward by the web feet of the loon. Speaking of this bird Burroughs says that in the water "its wings are more than wings. It plunges into this denser air, and flies with incredible speed. Its head and beak form a sharp point to its tapering neck. Its wings are far in front, and its legs equally far in the rear, and its course through the crystal depths is like the speed of an arrow. In the northern lakes it has been taken forty feet under water upon hooks baited for the great lake trout. I had never seen one till last fall, when one appeared on the river in front of my house. I knew instantly it was the loon. Who could not tell a loon a half-mile or more away, though he had never seen one before? The river was like glass, and every movement of the bird as it sported about broke the surface into ripples, that revealed it far and wide. Presently a boat shot out from shore, and went ripping up the surface toward the loon. The creature at once seemed to divine the intentions of the boatman, and sidled off obliquely, keeping a sharp look-out as if to make sure it was pursued. A steamer came down and passed between them, and when the way was again clear the loon was still swimming on the surface. Presently it disappeared under the water, and the boatman pulled sharp and hard. In a few moments the bird reappeared some rods further on, as if to make an observation. Seeing it was being pursued, and no mistake, it dived quickly, and when it came up again had gone many times as far as the boat had in the same space of time. Then it dived again, and distanced its pursuer so easily that he gave over the chase and rested upon his oars. But the bird made a final plunge, and when it emerged upon the surface again it was over a mile away. Its course must have been, and doubtless was, an actual flight under water, and half as fast as the crow flies in the air. The loon would have delighted the old poets. Its wild, demoniac laughter awakens the echoes on the solitary lakes, and its ferity and hardiness were kindred to those robust spirits." Another specially interesting bird which does something nearly approaching to flying under water is the dipper. The ouzel is essentially a bird of the running brook, though as to what part this pretty white-breasted thrush plays in the economy of nature naturalists are by no means agreed. Its most frequent stand is upon some mossy stone in a river reach, and here its crescented form may oftenest be seen. It haunts the brightly-running streams in winter as in summer, and when these are transformed into roaring torrents seems to love them best. Let us watch it awhile. It dashes through the spray and into the white foam, performing its morning ablutions. Then it emerges to perch on a stone, always jerking its body about, and dipping, dipping, ever dipping. Presently it melts into the water like a bubble, but immediately emerges to regain its seat, then trills out a loud wren-like song, but, breaking off short, again disappears. We are standing on an old stone bridge, and are enabled to observe it closely. By a rapid, vibratory motion of the wings, it drives itself down through the water, and by the aid of its wide-spreading feet clings to and walks among the pebbles. These it rapidly turns over with its bill, searching for the larvæ of water flies and gauzy-winged ephemeræ. It searches the brook carefully downwards, sometimes clean immersed, at other times with its back out, then with the water barely covering its feet. It does not always work with the stream, as we have frequently seen him struggling against it, but retaining its position upon the bottom. Even at the present day there are naturalists who, from the examination of cabinet specimens, aver that it is not in the power of the bird to walk on the bottom of the brook, but then they know nothing of him along his native streams.
Taking advantage of two birds remarkable for their long and sustained powers of flight, experiments have recently been conducted with a view to utilising swallows and pigeons as war messengers. In this connection the use of trained pigeons is one of the oldest institutions in the world; though now that certain European Powers have trained falcons to cut down pigeons, it is said that the pigeon-post is not sufficiently reliable. In consequence a number of French savants recently approached the Minister of War, and induced him to found a military swallow-cote whence