Popular Science Monthly/Volume 45/May 1894/Up the Chimney
By FRANK BOLLES.
LYING flat upon my back on my bedroom floor, with my bead in the fireplace, pillowed upon the andirons, and my gaze directed intently up the chimney, I watched, hour by hour, the strange domestic doings of two of my tenants. The fireplace was so arranged, and its opening into the chimney so shaped, that I could see much of that part of the interior of the chimney which rose above me, leading toward the little patch of blue sky far away. The whole of the west wall of the black flue, and a little more than half of both the north and south walls, were visible to me. The surface of these walls was rough, having been daubed with mortar which formed undulations and ridges. The lower faces of these irregularities were soft, dull black, but the parts inclined toward the sky caught the glare of light from above and shone as though ebonized. About eight feet above me, as I lay in the second-story fireplace, something about the size of half a small saucer projected like a tree fungus from the northern wall of the flue. Its edges gleamed like silvery gelatin, and light shone through its fabric in many places. This fabric seemed to be made of dozens of small twigs matted and woven together in semi-saucer form, and held firmly in place by some translucent, gelatinous substance of a yellowish-white color. Masses of the same substance held the shallow nest in its place against the hard, cold wall of brick and mortar. Protruding from the nest were the long and slender wings of a bird, which was sitting snugly upon the structure, with her face turned directly to the bricks. The tapering wings crossed near the body, and their tips spread like a Y, under which a short, stiff, fan-shaped tail extended, for a part of the distance covered by the wings. These stiff tail feathers, kept spread all the time, terminated in sharp spines, readily discernible. Occasionally, as I watched, the sitting bird wriggled on her nest, and her wings moved restlessly.
Suddenly the column of air in the chimney was thrown into vibration, and a dull booming sound resulted. Something darkened the opening of the shaft, the interrupted light trembled in a confusing way; I was strongly inclined to get out from under, and found it impossible to avoid closing my eyes. Simultaneously with these disturbing events, a bird's voice in the chimney produced a series of rapid whistling or peeping notes, so mingled as to render the hearer uncertain as to the number of birds making them. A second bird had entered the chimney. Seen from outside, he had dropped into it, and, watched by perturbed vision 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 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 and six in the morning, they came and went, went and came with apparently sleepless energy. The nights were clear and dry, and in the sky or over the white surface of the lake, insects were probably easily seen at any hour by birds accustomed to such gloom as that of my chimney. Still it was wonderful to think of their strength and patience, and of their knowledge of place. Many, if not most, of us poor mortals lose our paths under the simplest conditions, even with the sun smiling down upon us, or the stars writing their ancient guide-boards anew for us in the dark heavens, toward which we will not turn for aid. These swifts, however, seem to plow through darkness or light with equal confidence, cleaving the cool wind at the rate of more than a mile a minute, seeing first the pale lake below their chimney's shadow, then the vast peak of Chocorua, framed in its somber spruces, and again some far range of untrodden mountains where fellow swifts still nest in hollow tree trunks, after the ancient practice of their family. What marvelous sense is it which brings them back by day or by night, in sunlight or in storm, straight as thought itself, to home and rest?
I never have met a man who remembered having seen a swift perch. It was formerly supposed that they had no feet, and some people still believe the fable. In building time the birds come spinning through the air like projectiles, and while flying thus, snap small terminal twigs from sycamores and other brittle trees, and carry them back to their chimneys, to be painstakingly glued into their fragile nests. After seeing my swifts use their feet so readily in getting to and from their nest, I shall not be much surprised some day to see a swift alight upon some convenient perch outside his chimney. Nevertheless, so far as is now known, the swifts take no rest even after flying many miles with incredible speed, until their accustomed shelter is regained.
When Saturday came, I felt that it was time to see more of my noisy tenants. In the intervening days something which looked like a happy thought had come to me. Why should I lie supine among the fire irons, gazing up the black chimney hole, when, by judicious use of a few mirrors, I could bring the swifts and their cavern within range of my writing table? Saturday morning the small mirror climbed the flue a second time, and was firmly lashed in position a few inches above the nest. The lashing, of course, was applied to the butt of the fishing rod, at the point where it rested in the fireplace among andirons and tongs. Then a narrow, old-fashioned mirror, in which somebody's great-grandmother may have admired her pretty face in the days of a long-forgotten honeymoon, was gently rested upon the single stick of wood at the back of the fireplace so that its face inclined slightly toward me. Wonderful!—there were the shiny flue, the nest, the frightened bird perching far up the shaft, and the narrow line of sky above her; and there also was the small glass at the tip of my fishing rod, and in its oval face was an image of the inside of the shallow nest with two fat, featherless, sightless swifts flopping about in it. Nothing could now be easier than to watch the entire process of rearing the infant projectiles from a state of feebleness and imbecility to that marvelous condition of grace, speed, and intelligence at which they would, in the natural course of events, arrive in a few brief days.
My first desire was to ascertain how they were fed. The barn swallows, who by some freak have taken possession of a pewee's nest just under the eaves of my cottage, feed their young with insects which they bring bristling in their beaks. I had expected to see the swifts bring insects to their babies, but my closest scrutiny failed to discover anything in their beaks when they arrived, or when they went upon the nest. Under the new conditions I watched with double care and attention. At first, for nearly an hour, the birds were too much disturbed by the glass and fishing rod to settle upon the nest. They came close to it and chattered, but flew nervously and noisily, as though to frighten away the intruder. After a while they grew quieter, and finally one arrived with food. She came to the nest, mounted its edge, and leaned toward the open-mouthed young. Then she moved violently, and seemed to hang over the infants, to pound them, shake them, and push them back and forth in a singularly rough and unkind way. Seeing all these things by double reflection and in the dim light of the chimney, I could not be certain of details, but all that I saw reminded me of descriptions I had heard and read, of feeding young birds by regurgitation, while nothing that went on looked like the quiet and matter-of-fact process of dropping a fly into a little bird's gaping mouth. It seemed to me that the parent inserted her bill in the young one's throat, and then presumably pumped into it, by the violent motions which she made, a portion of the food previously swallowed by her. After being fed, the young dropped back limp or satisfied into the nest, and were promptly sat upon and hustled into a comfortable and orderly condition. Apparently both birds joined in feeding their offspring, for I saw first one and then the other go through this peculiar process.
Supposing that I should have ample opportunity for several days to watch the feeding, I did not devote myself to its study as faithfully as I should have, had I foreseen the distressing event which was in store for my tenants. On Saturday afternoon a light rain fell. The faithful mother sat upon her nest while multitudes of tiny drops floated down the chimney. They did not fall, but seemed to sail unwillingly through the gloom, held aloft by the ascending currents of air. Each globule shone with light, and looked almost as white as a snowflake. As they approached the nest few seemed to touch it, but curved away from it in some eddy of the air, and settled down into the depths of darkness below. During the rain both birds remained in the chimney most of the time. Sunday, July 16th, proved to be an unusually warm day, and, what was perhaps of more moment to the swifts, a very dry day, there seeming to be no moisture left in air or vegetation. About noon, while writing at my table, I heard the familiar booming, whistling, and chirping in the chimney, and as I glanced up I saw that one of the birds was coming to the nest and the other just going off up chimney. Suddenly there was a grating sound, a sharp outcry, more booming and fluttering, and I jumped to my feet and knelt before the glass to gain a closer view of the chimney. The nest had vanished. Only a tiny piece of glue adhered to the slight curve in the bricks under which the nest had been attached. The parent bird, with ruffled plumage and rapidly moving head, clung near the spot where her home had been, and seemed to me to be looking with terror far down into that horrible abyss where her young had fallen, and from which they sent back no cry. Taking down the pointed rod, I used the small mirror to search every part of the great chimney cavern which could be reached, but in vain. The nest had gone straight down without touching any fireplace, and had been lost forever in the débris and stifling dust at the bottom of the shaft.
During the remainder of the day the birds fluttered back and forth and lamented. They did not go more than two or three inches below the spot where the ill-fated nest had been. At intervals during the night I heard them moving in the chimney, but on Monday they stayed away most of the time, even during a heavy shower which fell late in the afternoon. Toward evening I saw both of them perched near the site of their fallen home, and during that night and on other days and nights the sound of their wings occasionally came to me as a reminder of their vanished happiness. They made no effort to rebuild in my chimney, yet their presence in it seemed to show that they had not begun housekeeping elsewhere. I doubt not that another summer, that love of home which is so closely connected with birds' ability to find a familiar spot by day or by night, even after months of absence, will bring my swifts back to their old flue.
It appears from the altitudes of the highest clouds measured at Upsala, Sweden, Kew, England,and Blue Hill, Mass., that the upper limit of ordinary clouds in temperate latitudes is between thirteen and fifteen kilometres, or nine miles; but it is possible that more numerous measurements may extend it to ten miles.