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