Page:Popular Science Monthly Volume 45.djvu/37

Rh from below, he had come down backward, hovering and fluttering until, head toward the light, his tiny feet had caught in the mortar and every spine in his very brief tail had been braced against the same rough substance. Perfectly motionless, he clung to the black wall as a tree toad sticks to a tree trunk. His flat head, tiny beak, sooty brown coat, shining in the glare from the sky, did not combine well into a bird; in fact, nothing in their weird surroundings made these tenants seem akin to birds. They were more like bats.

Outside, the hot sunlight and hazy blue sky of early July hung over wood and meadow, lake and distant mountain. Butterflies fluttered and drifted in aimless flight over the sumacs, a humming bird buzzed in the deep blue larkspur flowers, barn swallows cut fanciful curves over the lake and back to their nest with its nestlings; while down in the shadowy fern land the veery's tremulous music told of coolness and comfort. How different this soot lined tube of brick, leading down through everdarkening gloom into an unknown abyss of blackness and silence I How strange that this keen-eyed swift, which a moment ago was speeding through highest ether at a rate which no other bird can equal and maintain, should come back into this pit and call it his home! He spoke again, and once more the heavy air of the chimney responded to his whirring wings, as he dropped a little lower to the level of the nest, and turned his bright eyes inquiringly toward his mate. Her wings now moved, and she lifted herself away from the frail platform of glued twigs and stuck against the bricks a few feet distant. The male, raising his wings and keeping them moving, walked flylike to the nest and settled upon it. Instead of facing directly toward the north wall, he sat upon the nest at a different angle, so that his forked wings projected obliquely from the nest's edge. A moment later the female made the air throb and boom to her powerful flight as she flew toward and into the light.

Twenty minutes passed; the bird on the nest was restless, and squirmed in a way which suggested physical discomfort. Then he gave a low call; and a moment later darkness, hurried notes, and the fluttering of strong wings announced the mother-bird's return. She dropped down backward until close beside the nest, struck and clung to the bricks, and then, using her feet almost as well as though on level ground, gained the nest and pushed her way upon it, fairly forcing off her mate, who seemed to have no inclination to depart. Finally he moved, and, after a series of short upward flights, regained the sunlight, and was seen no more for three quarters of an hour. As the female settled herself upon the nest, a faint "cheeping" suggested that tiny life was stirring beneath her breast. Her position was the same which