she took in the first instance, her face being turned so directly toward the north wall that her tail projected at right angles from the nest. After seeing half a dozen exchanges in position made by the birds, I was satisfied that one parent, which I called the female, always sat straight upon the nest, and the other, which for the sake of distinguishing them I called the male, always sat obliquely.
To see only the bottom of the nest, yet to know that within it lay young swifts which were being fed in some way by their parents, was tantalizing. I recalled a former year, when I wished to secure a swift's nest with its full set of eggs, and so had kept watch of the nest; not by climbing to the chimney top and peering down, but by raising a small mirror, by whose aid I had seen the reflected nest from below. The mirror served its purpose a second time. I lashed it to the tip of a fishing rod, and pushed the slender joint up the chimney, adding first the middle joint and then the butt, in order to bring the glass well above the nest. Something white was in the nest—just what, I could not at first tell, for mortar dust had fallen into my eyes, and it was difficult to keep the glass still enough to see with my eyes blinking and weeping. The mother-bird had been driven from the nest by the appearance of the strange, misshapen thing which I had forced toward her from below, and she was now making short flights back and forth in the upper part of the chimney, producing sounds and sudden variations in light and darkness which would surely have frightened away any but a human intruder. Wiping my eyes and steadying the glass, I took a careful look at the contents of the nest. The white object, or at all events its whitest part, was an eggshell from whose opened halves a young bird was feebly trying to escape. Without waiting to see more, I withdrew the mirror from the chimney and removed all disturbing objects, myself included, from the fireplace. My heart reproached me. Had my violence driven the birds from their nest, thus making probable the death of the young at this trying crisis in their career? More than fifteen minutes passed before booming wings in the swift's grewsome nursery assured me that a parent had returned.
These events happened on Monday, and not until the following Saturday did I again intrude upon my batlike neighbors. Meanwhile I was not unaware of their near presence, for at all hours of the day and night the thunder of their wings and their high-pitched voices invaded my room. After exchanging places at intervals of from fifteen to forty-five minutes all day long, it seemed to my human intelligence that they might keep still at night. But no, during evening twilight, and at ten, twelve, one, and three o'clock, and then with tenfold energy between dawn
