Part 17
I have in another essay spoken of the scarcity of birds and other animals in the primitive forest. They are not numerous there, because the forest would yield them only a scanty subsistence. The forest border is their nursery and their shelter, but their best feeding-places are the cultivated grounds. There is not a single species whose means of subsistence are not increased by the clearing of the forest and the cultivation of the land; but they require a certain proportion of wild wood for their habitation. Very few species build their nests in the trees and shrubbery of our gardens, unless they are near a wood. In that case the catbird often nestles in the garden, that during the rearing of its young it may be near the grounds that produce larvæ. Most of the woodpeckers, the sylvias, and the small thrushes, including some of our most valuable birds, cannot rear their young except in a wild wood. Yet all these, solitary as they are in their habits, increase under favorable circumstances with the multiplication of insects consequent upon the culture of the soil. It may be affirmed as an indisputable truth, that if their increase were not checked by the sporting habits of men and boys, and the clearing and grubbing habits of “model farmers,” birds of every species would increase in the same ratio with the multiplication of their insect food, and proportionally diminish their ravages.
THE BLACK OR CHERRY BIRCH.
The epithets “black,” “white,” “red,” and “yellow,” which are so commonly misapplied to certain trees for specific distinction,—a misapplication very remarkable with reference to the poplar,—are very well applied to the different species of birch, and serve as intelligible marks of identity. The Black Birch, for example, is clothed with a dark-colored bark, which comes nearer a pure black than any other color. No person would dispute the color of the white birches; that of the yellow birch, though not pure, would never be mistaken for anything but yellow; and the bark of the red birch, though nearly white, is so thoroughly stained with red as to demonstrate the propriety of its name.
The Black Birch is also named the Cherry Birch, from the resemblance of the tree to the American black cherry. Its inner bark has the flavor of checkerberry, and its wood some of the colors of mahogany; and it has received names corresponding with these characters, such as Sweet Birch and Mahogany Birch, and was formerly a favorite material for cabinet furniture. The bark of this species and of the yellow birch has very little of that leathery or papyraceous quality which is so remarkable in that of the white birches. This species does not extend so far north as the others, but has a wider geographical range in and below the latitude of New England.
The Black Birch puts forth its flowers very early in the year, of a deep yellow and purple and sensibly fragrant. The foliage also appears early. The leaves are finely serrate, oval, with conspicuous veins, turning yellow in the autumn. Not one of the birches ever shows a tint approaching to red or purple in its foliage. The Black Birch delights in moist grounds, and commonly occupies a stand on mountain slopes and on the banks of rivers. When growing singly on a plain, or in an open space, it takes a hemispherical shape, with its terminal and lower branches drooping to some extent like those of the elm. This tree is conspicuous on craggy precipices, among the mountains, where it extends its roots into the crevices of the rocks, and spreads its branches over chasms and hollows. On these sites it displays a variety of picturesque forms, corresponding with the rudeness and the wildness of the scenery around it. Nature has furnished this tree with a chaffy or winged seed, which is soon wafted and sown by the winds upon mountain-sides and among inaccessible rocks, where the soil collected in thin fissures supplies it with sustenance.
THE YELLOW BIRCH.
The Yellow Birch, named _excelsa_ by botanists, from its superior height, is perhaps the most beautiful of the genus. Its branches are extremely numerous, long and slender, corresponding with the superior length of its trunk, and they are prone, like those of the elm, to equality in size, and to divergency from nearly a common centre. Indeed, where this tree has grown as an isolated standard, it commonly displays a very symmetrical head, differing in form from a perfect elm only by less inclination to droop. The leaves of this species have much of the same quality which I have remarked as peculiar to the beech, every leaf standing erect upon its stem. The flexible appearance of the tree is derived entirely from its slender flowing branches.
The Yellow Birch is very abundant in Maine and New Brunswick, and formerly constituted the greater part of the wood which was brought into Massachusetts for fuel. Many of the logs were of immense size before the primitive forest was removed. At the present day we seldom find one more than eighteen inches in diameter, though many slender individuals still occupy our woods. It delights in cold, damp soils, and I have seen the finest standards near springs on an open hillside. The Yellow Birch derives its name from the golden hue of the bark that covers the trunk and larger limbs. This silken bark, which is rolled into multitudes of soft ringlets, is peculiar to this tree.
THE RED BIRCH.
The Red Birch is a rare species, and but very little known. By careless observers it might be mistaken for a white birch, the redness of its bark seeming only a departure from its usual type. The only trees of this species I have seen in Massachusetts were in Andover, in a swamp through which the Shawsheen River flows. If you would behold this tree to the best advantage, you must follow the streams that glide along the level woodlands which are inundated a part of the year. There it may be seen, like some pilgrim bending worshipfully over the stream, by whose beneficent waters it is sustained in beauty and health. Its picturesque attractions, arising from the great variety of its outlines and the peculiar wreathing of its foliage around the stem, are not surpassed by those of the willow, that delights in similar places. The reddish whiteness of the bark and wood has given the name to this tree. It is a tall, bushy tree of rapid growth, rolling up its bark in coarse ringlets, which are whitish with a stain of crimson.
THE INDIAN SUMMER.
When November arrives, leading along with it the short days and the darkness of winter, it opens the windows of the deep woods, pervaded all summer by a sort of artificial twilight. The general denuded state of the forest admits the sunshine into its interior, and brightens it with a cheerfulness exceeding that of any other season. Some light-tinted leaves still remain upon the trees which have been screened by their situation from the frost and the wind, and many an interesting object is exposed to view which was concealed by the foliage in summer. A few asters and gentians still linger in some protected nook, and the chickadees and hemp-birds make the wood lively by their garrulity and their motions. The ground is covered with red, brown, and yellow leaves, making a pleasant carpet for our feet, and increasing all the pleasures of a woodland ramble.
After the fall of the leaf is completed, then, according to tradition, comes the Indian Summer,—a fruitful theme both for poets and philosophical writers, but of which no one knows anything from experience. It may, after all, be only a myth, like the halcyon days of the ancients, the offspring of a tradition that originated with certain customs of the Indian, and which occasional days of fine weather in the autumn have served to perpetuate. It is certain that we have now in the Eastern States no regular coming of this delightful term of mildness and serenity, this smiling interruption of the melancholy days of autumn. We are greeted occasionally by two or three days resembling it after the first cool weather of October, and these short visits are in some years repeated several times. But a true Indian Summer, attended with all the peculiar phenomena described by some of our early writers both in prose and verse, rarely accompanies a modern autumn. It has fled from our land before the progress of civilization; it has departed with the primitive forest. I will, however, for the present, set aside all my conjectures of its mythical character, and treat it as a matter of fact.
The Indian Summer, if such a season was ever known, was a phenomenon produced by some unexplained circumstances attending the universal wooded state of the country that existed for many years after its settlement. According to the most apparently authentic accounts, it did not arrive until November, nor until a series of hard frosts had destroyed all the leaves of the forest. It then appeared regularly every year. At the present time people know so little about it that they cannot name the period of the autumn when, if it were not a thing of the past, it should be expected. Will the disappearance of this phenomenon admit of a philosophic explanation? Let us consider some of its probable causes, and the effects of the changes which have taken place in our land.
It has been observed that a meadow covered with luxuriant grass and other herbage cools the atmosphere that rests upon it much more rapidly than a similar meadow covered with a scanty herbage. The moisture exhaled into the air by vegetable perspiration is greater than from any other natural surface; and as the radiation of heat is rapid in proportion to the moist condition of the atmosphere, the cooling process over a grassy meadow is vastly greater than over a similar ground bare of vegetation. A wood, in like manner, by exhaling through its foliage the moisture it draws from the earth, cools the atmosphere in proportion to the amount of its foliage, while at the same time it shades the ground from the sun. Anything that should check this vegetable perspiration would in the same ratio preserve the heat of the atmosphere by diminishing the radiation of heat that takes place more slowly in dry than in moist air.
This is precisely what happens soon after the first severe frosts of November, when the whole extent of the forest over thousands of miles is laid bare in the brief space of two or three days. There is a sudden and universal diminution of the moisture that was given out from the leaves of trees and other plants before the frost had destroyed them; for the evaporation caused by the drying of fallen leaves and herbage is comparatively slight, and ceases after a few hours’ exposure to the sun. The atmosphere being dry, and the radiation of heat proportionally small in quantity, all these circumstances, if no unusual atmospheric disturbances occur from any other hidden cause, unite in producing a sudden and universal accumulation of heat. The warm period that follows is the Indian Summer.
A writer in “Silliman’s Journal” of 1833, who advances a very different theory to explain this phenomenon, makes a statement that favors my view: “It appears to us that the existence and duration of the Indian Summer in this country has an important connection with the extensive forests and uncultivated lands peculiar to America. And it is worthy of remark, that, according to the recollection of the oldest of our inhabitants, its former duration was often three or four weeks; whereas its present continuance is short and uncertain, seldom exceeding ten or fifteen days. It appears also that this decline has been somewhat regular, keeping pace with, and evidently influenced by, the gradual uncovering of the country.”
It is surprising that the writer, after making these observations, should resort to some unintelligible reasoning about the trade-winds, and certain assumed electric phenomena, to account for the Indian Summer. I can easily believe that before the encroachments upon the American forest were very extensive, this halcyon period of autumn may have occurred every year with great regularity. But since the clearing is almost universal, these conditions have been entirely changed. During the primitive state of the forest, its sudden denudation produced a more complete revolution on the face of the country than could possibly happen at the present time. The clearing of the woods has also cast down the barriers that impeded the circulation of the winds; at present these winds, sweeping freely over the continent, would counteract any influences, whatever they might be, that would produce an Indian Summer in any locality.
The true Indian Summer was a period of very mild weather, lasting from ten to fifteen days, and accompanied neither by wind nor rain. It has been incorrectly described by certain writers as attended with fog. The sky, though somewhat dim, was not obscured by vapor, but by a sort of ruddy haze, that veiled the prospect, as it often will during a series of warm, still days happening at any season. I draw my inferences from what I have reason to consider the most authentic accounts. The air was dry; and it could not have been otherwise. If it were moist, the increased radiation would soon dissipate the heat and put an end to the Indian Summer, which was never known to survive a copious and extensive fall of rain. The atmosphere was described as being obscured by smoke, rather than vapor, and this was most apparent in the latter part of the day. This smoky atmosphere has led some writers to suppose the whole phenomenon to be caused by fires in the woods.
According to tradition, no part of the year was more delightful than this short period. Those accounts, however, that extended its duration beyond the space of fourteen or fifteen days were undoubtedly exaggerated. The nearest approaches to an Indian Summer which I have witnessed in its proper season have never lasted a week. In our day, when a warm week occurs in the autumn, it comes at no regular or expected time. This irregularity of its occurrence proves that it is not to be identified as the Indian Summer, which was regular in its happening immediately after the entire denudation of the forest. Similar but shorter periods of mild and serene weather may happen, at the present epoch, in winter and spring as well as in autumn. These irregularities of the weather cannot be explained; nor can we make predictions of the time when any of them may happen. But a warm period in October or December or January is not an Indian Summer, which belonged to November, and is only a relic of the past.
The origin of the name is explained by Dr. Lyman Foot, in the third volume of “Silliman’s Journal.” He says: “If you ask an Indian in the fall when he is going to his hunting-ground, he will tell you when the fall summer comes, or when the Great Spirit sends our fall summer; meaning the time in November which we call the Indian Summer. And the Indians actually believe that the Great Spirit sends this mild season in November for their special benefit.”
THE POPLAR.
In the latter part of April, some of the most conspicuous groups in many of the wooded districts of Northern New England are Poplar woods, full of olivegreen aments, and giving the hue of their blossoms and of their pale green spray to large portions of the forest in scattered assemblages. At this period the poplars are an important ingredient in our wood-scenery, especially as their colors vary considerably from those of other trees until all kinds are in full foliage. They have the merit also of preceding a greater part of the forest in the development of their flowers. The aments of a few species are variegated with red and purple stamens; but the generality do not vary from a pure olive. The Poplar has not many of the qualities of a beautiful or picturesque tree. It is marked by a coarse and straggling spray, without any variety in its combination. It is deficient in beauty and density of foliage, which is chiefly remarkable for its fragrance and tremulous habit.
All the poplars are rapid in their growth, and will prosper in almost all situations. They prefer a moist, sandy soil, but shun the peat meadow. Their rapidity of growth renders them valuable where a speedy plantation is wanted. Hence they are very generally planted by the sides of dusty thoroughfares, not being dainty in their choice of soil and situation. The species generally employed for such purposes is the Abele, or Silver Poplar, which possesses these requisite properties in a higher degree than our native trees. It displays also more beauty of foliage, and takes a rounder and handsomer shape than most others. One of the defects which I have frequently observed in the shape of the large poplars is a leaning of the branches rather awkwardly toward the south-east, caused by the prevalent north-west winds acting upon branches of great proportional length, and possessing very little elasticity. This inclination is observed more or less in other soft-wooded deciduous trees.
THE CANADA POPLAR.
The Canada or Balm of Gilead Poplar is more frequent by our waysides than any other species. It is a tree of the first magnitude, attaining a great size in the bole as well as a superior height. It is distinguished by its large leaves, of a bright glossy verdure, and its long branches, always subordinate to the central shaft, which may be traced nearly to the summit of the tree. Before the leaves begin to expand, the buds are covered with a yellow glutinous balsam, that diffuses a peculiar and very penetrating but agreeable odor, unlike any other. Sir John Franklin remarks that this tree constitutes “the greatest part of the drift timber observed on the shores of the Arctic Sea.” It has a very wide geographical range, extending from Canada to the Missouri River, and is in many places called the Ontario Poplar. It is abundant in the northern woods, but is found in the southern parts of New England only by the roadsides and in the enclosures of dwelling-houses. The balsam is gathered in all parts of the country as a healing anodyne, and for many ailments it is a favorite remedy in domestic medicine; but no place has yet been assigned to it in the pharmacopœias. All the poplars produce more or less of this substance. It is very different from turpentine, more agreeable when perceived in the air, but pungent and disagreeable to the taste.
THE BLACK POPLAR.
There are several of the poplars that are not easily distinguished, and the different and various accounts of them by botanists have increased this confusion. Part of the difficulty arises from the diœcious character of the poplar, causing in some instances the male and female trees to be mistaken for different species. This is particularly remarkable in the Balm of Gilead poplar. The female tree is smaller than the male, with larger leaves, and annoys us by the abundance of cottony down that covers the ground for a considerable space around it. The male tree is taller and more spreading, and would hardly be recognized as the same species.
The Black Poplar is often planted by roadsides with the Canada poplar, and may be distinguished from it by the greater elegance of its proportions, its smaller foliage, and, when in flower, by its reddish and purple catkins. It is preferred to other species on account of an inferior tendency to that suckering habit which is so disagreeable in the poplar tribe. It seems to me that no persons who should see the Canada poplar and the Black Poplar growing side by side, would hesitate in giving preference to the latter, which is in almost every point a more beautiful tree.
This species is called in Europe the Athenian Poplar. According to Selby, “the classic appellation of Athenian Poplar led to the supposition in England that this species is indigenous to Greece, and that it derived its name from the city of Minerva. Several learned botanists were misled by this name; but it was finally ascertained that North America is its native country, and from its abundance in a particular township called Athens it received the imposing title of Athenian Poplar.”
THE RIVER POPLAR.
The River Poplar is not rare in the New England forest, but it is little known as an ornamental tree. Emerson says: “It is much the tallest and most graceful of those which grow naturally in New England. Its foliage is equal to that of the Balm of Gilead in size, and superior to it in depth of color; and the abundance of its aments in the spring, and the rich colors of its leaf-stalks and young branches, when growing in somewhat dry situations, make it a beautiful object.” The aments of this tree are not olive-colored, like those of the two aspens, but inclining to red, though not so bright as those of the black and Lombardy poplars. It is very justly called the River Poplar, being found chiefly in wet places, near brooksides, on the banks of rivers, and in alluvial valleys which are liable to be inundated in spring. This tree displays the characteristic peculiarities of the family in giving out its lateral branches at a sharp angle and subordinate to the trunk.
SOUNDS FROM TREES.
“The earliest chant,” says Momsen, “in the view of the Romans, was that which the trees sang to themselves, in the green solitudes of the forest. The whisperings and pipings of the _favorable spirit_ in the grove were repeated by the singer, with the accompaniment of the pipe.” Certain trees belonging to the sacred groves gave oracular sounds, which were interpreted by musicians, and received by all men with faith and reverence. From the earliest ages men have listened to sounds from trees as music and as the voice of some deity, affording auguries of future events; for, as they reasoned, if a deity speaks to us, what sounds would be a more appropriate medium of communication than those of the trees which formed their temples and their altars? The sanctity attributed to certain groves by the ancients was probably owing to some peculiar sounds emitted by the trees, no less than to the grandeur and impressiveness of their assemblages.
Every tree, when swept by the winds, gives a sound in harmony with the character of its leaves and spray. The sounds from the lofty branches of firs and pines remind the listener of the murmuring of waters, and inspire the most agreeable sensations. How often have I sat under the shade of a pine wood, and listened to the fancied roaring of the distant waves of the sea, as the winds passed through their foliage. When the breeze commences, we hear the first soft rippling of the waves; as it increases, succeeding waves of fuller swell flow tremulously upon the strand, and as the wind subsides melt into silence as they recede from the shore. Other trees produce very different sounds. The colors of their leaves, and the glittering lights from their more or less refractive surfaces, do not differ more than the modifications of sound drawn from them by the passing winds. Every tree is a delicate musical instrument, that reminds us of the character of the tree and the season of the year, from the mellow soothing tones of willow leaves in summer to the sharp rustling of the dry oak-leaf that tells of the arrival of winter.