Kitabı oku: «Harper's New Monthly Magazine, No. XXVI, July 1852, Vol. V», sayfa 14

WHAT THE SUNBEAM DOES

Heat, or the caloric portion of the sunbeam, is the great cause of life and motion in this our world. As it were with a magical energy, it causes the winds to blow and the waters to flow, vivifies and animates all nature, and then bathes it in refreshing dew. The intensity of the heat which we receive depends on the distance of the earth from the sun, its great source, and still more on the relative position of the two orbs; since in winter we are nearer the sun than we are in summer, yet, in consequence of the position of the earth at that season, the sun's rays fall obliquely on its northern hemisphere, rendering it far colder than at any other period of the year.

A great portion of the heat-rays which are emitted by the sun are absorbed in their passage through the atmosphere which surrounds our globe. It is calculated that about one-third of the heat-rays which fall on it never reach the earth, which fact adds another to the many beneficent purposes fulfilled by our gaseous envelope, screening us from the otherwise scorching heat. It is curious to trace the varied fates of the calorific rays which strike on the surface of the earth. Some at once on falling are reflected, and, passing back through the atmosphere, are lost amid the immensity of space; others are absorbed or imbibed by different bodies, and, after a time, are radiated from them; but the greater part of the beams which reach the earth during the summer are absorbed by it, and conveyed downward to a considerable distance, by conduction from particle to particle. Heat also spreads laterally from the regions of the equator toward the poles, thereby moderating the intense cold of the arctic and antarctic circles, and in winter, when the forest-trees are covered with snow, their deeply-penetrating roots are warmed by the heat, which, as in a vast store-house, has been laid up in the earth, to preserve life during the dreary winter. The rays which fall on the tropical seas descend to the depth of about three hundred feet. The sun's attraction for the earth, being also stronger at that quarter of the world, the heated waters are drawn upward, the colder waters from the poles rush in, and thus a great heated current is produced, flowing from the equator northward and southward, which tends to equalize the temperature of the earth. The sailor also knows how to avail himself of this phenomenon. When out at sea, despite his most skillful steering, he is in constant danger of shipwreck, if he fails to estimate truly the force and direction of those currents which are dragging him insensibly out of the true course. His compass does not help him here, neither does any log yet known give a perfectly authentic result. But he knows that this great gulf-stream has a stated path and time, and, by testing from hour to hour the temperature of the water through which he is proceeding, he knows at what point he is meeting this current, and reckons accordingly.

We have already said that heat was the producer of the winds, which are so essential to the preservation of the purity of the atmosphere. In order to understand their action, we shall consider the stupendous phenomenon of the trade-winds, which is similar to that of the current we have described. The rays of the sun falling vertically on the regions between the tropics, the air there becomes much heated. It is the property of air to expand when heated, and, when expanded, it is necessarily lighter than the cooler air around it. Consequently it rises. As it rises, the cooler air at once takes its place. Rushing from the temperate and polar regions to supply the want, the warm air which has risen flows toward the poles, and descends there, loses its heat, and again travels to the tropics. Thus a grand circulation is continually maintained in the atmosphere. These aerial currents, being affected by the revolution of the earth, do not move due north and south, as they otherwise would. Hence, while they equalize the temperature of the atmosphere, they also preserve its purity; for the pure oxygen evolved by the luxuriant vegetation of the equatorial regions is wafted by the winds to support life in the teeming population of the temperate zones, while the air from the poles bears carbonic acid gas on its wings to furnish food for the rich and gorgeous plants of the tropics. Thus the splendid water-lily of the Amazon, the stately palm-tree of Africa, and the great banyan of India, depend for nourishment on the breath of men and animals in lands thousands of miles distant from them, and, in return, they supply their benefactors with vivifying oxygen.

Little less important, and still more beautiful, is the phenomenon of dew, which is produced by the power of radiating heat, possessed in different degrees by all bodies. The powers both of absorbing and of radiating heat, in great measure, depend on the color of bodies – the darker the color, the greater the power; so that each lovely flower bears within its petals a delicate thermometer, which determines the amount of heat each shall receive, and which is always the amount essential to their well-being. The queenly rose, the brilliant carnation, the fair lily, and the many-colored anemone, all basking in the same bright sunshine, enjoy different degrees of warmth, and when night descends, and the heat absorbed by day is radiated back, and bodies become cooler than the surrounding air, the vapor contained in the atmosphere is deposited in the form of dew. Those bodies which radiate most quickly receive the most copious supply of the refreshing fluid. This radiating power depends on the condition of the surface, as well as upon color, so that we may often see the grass garden bathed in dew, while the gravel walks which run through it are perfectly dry, and, again, the smooth, shining, juicy leaves of the laurel are quite dry, while the rose-tree beneath it is saturated with moisture.

The great effect produced on the vegetable kingdom by the heat-rays may be judged of from the fact, that almost all the plants which exhibit the remarkable phenomena of irritability, almost approaching to animal life, are confined to those regions where the heat is extreme. On the banks of the Indian rivers grows a plant in almost constant motion. In the hottest of the conservatories at Kew is a curious plant, whose leaflets rise by a succession of little starts. The same house contains Venus's fly-trap. Light seems to have no effect in quickening their movements; but the effect of increased heat is at once seen. They exhibit their remarkable powers most during the still hot nights of an Indian summer.

Heat is of essential importance in the production and ripening of fruit. Many trees will not bear fruit in our cold climate, which are most productive in the sunny south. Animal as well as vegetable life is in great measure dependent on heat. Look at the insect tribes. The greater number of them pass their winter in the pupa state. Hidden in some sheltered nook, or buried in the earth, they sleep on, until the warmth of returning spring awakens them to life and happiness; and if, by artificial means, the cold be prolonged, they still sleep on, whereas, if they he exposed to artificial heat, their change is hastened, and butterflies may be seen sporting about the flowers of a hothouse, when their less favored relatives are still wrapped in the deepest slumber. To judge of the influence of heat on the animal and vegetable economy, we need but contrast summer and winter – the one radiant and vocal with life and beauty, the other dark, dreary, and silent.

The third constituent of the sunbeam is actinism – its property being to produce chemical effects. So long ago as 1556, it was noticed by those strange seekers after impossibilities, the alchemists, that horn silver, exposed to the sunbeam, was blackened by it. This phenomenon contained the germ of those most interesting discoveries which have distinguished the present age; but, in their ardent search for the philosopher's stone and the elixir of life, they overlooked many an effect of their labors which might have led them to important truths.

As yet, the effects of actinism have been more studied in the inanimate than the organic creation. Still, in the vegetable kingdom, its power is known to be of the utmost importance. A seed exposed to the entire sunbeam will not germinate; but bury it in the earth, at a depth sufficient to exclude the light, yet enough to admit actinism, which, like heat, penetrates the earth to some distance, and soon a chemical change will take place; the starch contained in the seed is converted into gum and water, forming the nutriment of the young plant; the tiny root plunges downward, the slender stem rises to the light, the first leaves, or cotyledons, then unfold, and now fully expand to the light, and a series of chemical changes of a totally different nature commence, which we have before noticed, when speaking of light. Experiments clearly prove that this change is to be attributed to actinism, and not to heat. Glass has been interposed of a dark blue color, which is transparent to actinism, though opaque to light and heat, and germination has been thereby quickened. Gardeners have long known this fact practically, and are accustomed to raise their cuttings under blue shades. There is no doubt that actinism exercises a powerful and beneficent influence on plants during their whole existence, but science has yet to demonstrate its nature; and it is curious to observe that the actinic element is most abundant in the sunbeam in the spring, when its presence is most essential in promoting germination – in summer the luminous rays are in excess, when they are most needed for the formation of woody fibre – and in autumn the heat-rays prevail, and ripen the golden grain and the delicious fruit; in each day the proportions of the different rays vary – in the morning the actinic principle abounds most, at noon the light, and at eventide the heat.

The influence of actinism on the animal world is not well known; but it is probable that many of the effects hitherto referred to light are in reality due to actinism. It has the strange power of darkening the human skin, causing the deep color of those tribes who inhabit the sunniest regions of the earth; and even in our own country, in summer, that darkening of the skin called sun-burning. Doubtless, more careful investigation will discover this principle to be equally important to the life and health of animals as either of its closely allied powers of light and heat.

Our knowledge of actinic influence on inanimate nature is not so scanty, for it is now a well established fact, that the sunbeam can not fall on any body, whether simple or compound, without producing on its surface a chemical and molecular change. The immovable rocks which bound our shores, the mountain which rears its lofty head above the clouds, the magnificent cathedral, the very triumph of art, and the beautiful statue in bronze or marble, are all acted on destructively by the sunbeam, and would soon perish beneath its irresistible energy, but for the beautiful provision made for their restoration during the darkness of night – the repose of darkness being no less essential to inorganic, than it is to animated nature. During its silent hours, the chemical and molecular changes are all undone, and the destruction of the day repaired, we know not how.

The art of painting by the sunbeam has been rather unfortunately called photography, which means light-painting, for the process is not due to light, but is rather interfered with by it; and, contrary to all preconceived ideas, the pictures taken in our comparatively sombre country, are more easily and brilliantly produced than in brighter and more sunny lands – so much so, that a gentleman, who took the requisite materials to Mexico, in order to take views of its principal buildings, met with failure after failure, and it was not until the darker days of the rainy season that he met with any measure of success.

THE RECORD OF A MADNESS WHICH WAS NOT INSANITY

A fresh, bright dawn, the loveliest hour of an English summer, was rousing the slumbering life in woods and fields, and painting the heavens and the earth in the gorgeous hues of the sunrise.

Beautiful it was to see the first blush of day mantling over the distant hills, tinging them with a faint crimson, and the first smile shooting, in one bright beam through the sky, while it lit up the fair face of nature with a sparkling light. Lilias Randolph stood on the flight of steps which led from the Abbey to the park, and looked down on the joyous scene. She seemed herself a very type of the morning, with her sunny eyes, and her golden hair; and her gaze wandered glad and free over the spreading landscape, while her thoughts roamed far away in regions yet more bright – even the sunlit fields of fancy.

It was the day and the hour when she was to go and meet Richard Sydney, in order to have, at length, a full revelation of his mysterious connection with her cousin. She knew that it was an interview of solemn import to both of those, in whom she felt so deep an interest; yet, so entirely were one thought and one feeling alone gaining empire over her spirit that, even then, in that momentous hour, they had no share in the visions with which her heart was busy.

So soon, therefore, as Lilias came within sight of Richard Sydney, who had arrived first at the place of rendezvous, she resolutely banished the thoughts that were so absorbing to her own glad heart, and set herself seriously to give her entire attention to the work now before her, if, haply, it might be given her, in some degree, to minister unto their grievous misery. And truly her first glance upon the face of the man who stood there, with his eyes fixed on the path which was to bring her and her hoped-for succor near to him, would have sufficed to have driven all ideas from her mind, save the one conviction, that in that look alone she had acquired a deeper knowledge of suffering than her own past life, in all its details, had ever afforded her. Sydney heard her step, long before she believed it possible, and, bounding toward her, he seized her hand with a grasp which was almost convulsive. He drew her aside to some little distance from her nurse, who sat down on a bank to wait for them.

Lilias bent down her head that she might not seem to note the workings of his countenance, as he laid bare before her the most hidden springs of his soul, and he began:

"I was born heir to a curse. Centuries ago an ancestor of mine murdered a woman he once had loved, because his neglect had driven her mad, and that in her ravings she revealed his many crimes. With her dying breath she invoked the curse of insanity on him and his house forever, and the cry of her departing soul was heard. There has not been a generation in our family since that hour which has not had its shrieking maniac to echo in our ears the murdered woman's scream. Some there have been among the Sydneys of peculiar constitution, as it would seem, who have not actually been visited with the malady; but they have never failed to transmit it to their children. Of such am I; while my father died a suicide by his own senseless act, and his only other child besides myself, my sister, wears her coronet of straw in the Dublin Asylum, and calls herself a queen.

"It would appall you to hear the fearful calamities which each succeeding family has undergone through this awful curse. At last, as the catalogue of tragic events grew darker and darker, it became a solemn matter of discussion to our unhappy race, whether it were not an absolute duty that the members of a house so doomed, should cease at last to propagate the curse, and by a resolute abandonment of all earthly ties, cause our name and misery to perish from the earth. The necessity for this righteous sacrifice was admitted; but the resolution in each separate individual to become the destined holocaust, has hitherto forever failed before the power of the mighty human love that lured them ever to its pure resistless joys. It was so with my father – like myself he was an only son; and, in the ardor of a generous youth, he vowed to be the offering needful to still the cry of that innocent blood for vengeance; but the sweet face of my mother came between him and his holy vow. He married her, and the punishment came down with fearful weight on both, when her fond heart broke at sight of his ghastly corpse. Then it was she knew the retribution in their case had been just; and on her dying bed, with the yet unclosed coffin of her husband by her side, she made me vow upon the holy cross that I, myself, would be the sacrifice – that never would I take a wife unto my heart or home; and that never, from my life, should any helpless being inherit existence with a curse. That vow I took, that vow I kept, and that vow I will keep, though Aletheia, beloved of my heart and soul, dearer than all beneath the skies, were to lay herself down beneath my very feet to die. Oh! shall we not rest in heaven."

He bowed his head for a moment, and his frame shook with emotion, but driving back the tide of anguish, he went on: "After my mother's death and my sister's removal, who had been insane almost from childhood, I shut myself up entirely at Sydney Court, and gave way to a species of morbid melancholy which was thought to be fearfully dangerous for one in my position. I had friends, however; and the best and truest was Colonel Randolph, my Aletheia's father, the early companion of my own poor, hapless parent. He was resolved to save me from the miserable condition in which I then was. He came to me and told me, with all the authority of his long friendship, that I must go with him to the M – , where he had been appointed governor. He said it was a crime to waste a life, which, though unblest by human ties, might be made most useful to my fellow-creatures. I had studied much in brighter days, and given to the world the fruits of my labors. These had not passed unheeded; he told me they had proved that talents had been committed to me whereby I might be a benefactor to my race, all the more that no soft endearments of domestic joys would wean my thoughts from sterner duties. I was to go with him; he insisted it would benefit myself, and would injure none. His family consisted of his one daughter, his precious, beloved Aletheia, for he doated on her with more than the ordinary love of a father. She knew my history, and would be to me a sister. Alas! alas! for her destruction, I consented."

Again, a momentary pause. Lilias gently raised her compassionate eyes, but he saw her not; he seemed lost in a vision of the past, and soon went on:

"That lovely land where I dwelt with her, it seems a type of the beauty and happiness which was around me then! And, oh! what a dream it is to think of now – the cloudless sky – the glorious sun – and her eyes undimmed, her smile unfaded! Oh! Aletheia – my Aletheia – treasure of many lives! bright and joyous – light to the eyes that looked on her, blessing to the hearts that loved her – would that I had died or ever I drew her very soul into mine, and left her the poor, crushed, helpless being that she is! You can not picture to yourself the fascination that was around her then – high-minded, noble in heart, lofty in soul; her bright spirit stamped its glory on her face, and she was beautiful, with all spiritual loveliness. None ever saw her who loved her not – her rare talents – her enchanting voice; that voice of her very soul, which spoke in such wonderful music, drew to her feet every creature who knew her; for with all these gifts, this wonderful intellect, and rarest powers of mind, she was playful, winning, simple as an innocent child. I say none saw her, and loved her not; how, think you, I loved her? – the doomed man, the desolate being, whose barren, joyless life walked hand in hand with a curse. Let this anguish tell you how I loved her;" and he turned on Lilias a face of ghastly paleness, convulsed with agony, and wet with the dews of suffering; but he did not pause, he went on rapidly: "I was mad, then, in one sense, though it was the madness of the heart, and not the brain. Poor wretch, I thought I would wring a joy out of my blasted life in spite of fate, and, while none other claimed her as their own, I would revel in her presence, and in the rapture of her tenderness. I knew it was mockery when I bid her call me brother – a sister truly is loved with other love than that I gave her. I would have seen every relation I had ever known laid dead at my feet, could I have thereby purchased for her, my thrice-beloved one, one moment's pleasure.

"Lilias, does a passion of such fearful power shock and terrify you, who have only known the placid beating of a gentle, childlike heart? Take a yet deeper lesson, then, in the dark elements of which this life may be composed, and learn that deep, and true, and mighty as was my love for her, it is as a mere name, a breath, a vapor, compared with that most awful affection which Aletheia had already, even then, vowed unto me, in the depth of her secret heart. Ah! it needed, in truth, such an agony as that which is now incorporate with it in her heart, to cope with its immensity; for, truly, no weak happiness of earth could have had affinity with it – a love so saint-like must needs have been a martyr. I will not attempt to tell you what her devotion to me was, and is, and shall be, while one faintest throb of life is stirring in her noble heart. You have seen it – you have seen that love looking through those eyes of hers, like a mighty spirit endowed with an existence separate from her own, which holds her soul in its fierce, powerful grasp.

"I must hurry on now, and my words must be rapid as the events that drove us from the serene elysian fields of that first dear companionship, through storm and whirlwind, to this wilderness of misery where I am sent to wander to and fro, like a murderer, as I am; condemned to watch the daily dying of the sweet life I have destroyed. You may think me blind and senseless, for so I surely was, but it is certain that I never suspected the love she bore me. I saw that she turned away from the crowds that flocked around, and was deaf to all the offers that were made to her, of rank, and wealth, and station, and many a true heart's love; but I thought this was because her own was yet untouched, and when I saw that I alone was singled out to be the object of her attention and solicitude, I fancied it was but the effect of her deep, generous pity for my desolate condition – and pity it was, but such as the mother feels for the suffering of the first-born, whom she adores. And the day of revelation came!

"I told you how Colonel Randolph doated on his daughter; truly, none ever loved Aletheia with a common love. When he was released from the duties of his high office, it was one of his greatest pleasures to walk, or ride with me, that he might talk to me of her. One morning he came in with a packet of letters from England, and, taking me by the arm, drew me out into the garden, that he might tell me some news, which, he said, gave him exceeding joy. The letters announced the arrival of the son of an old friend of his, who had just succeeded to his title and estates, the young Marquis of L – , and further communicated, in the most unreserved manner, that his object in coming to the M – was to make Aletheia his wife, if he could win her to himself; he had long loved her, and had only delayed his offer till he could install her in his lordly castle with all the honors of his station. To see this union accomplished, Colonel Randolph said, had been his one wish since both had played as children at his feet, and he now believed the desired consummation was at hand. Aletheia's consent was alone required, and there seemed no reason to doubt it would be given, for there was not, he asserted, in all England, one more worthy of her, by every noble gift of mind, than the high-born, generous-hearted L – .

"Why, indeed, should she not, at once, accept the brilliant destiny carved out for her! – I did not doubt it more than the exulting father, and I heard my doom fixed in the same senseless state of calm with which the criminal who knows his guilt and its penalty, hears the sentence of his execution. I had long known this hour must come; and what had I now to do but gather, as it were, a shroud round my tortured soul, and, like the Cæsars, die decently to all earthly happiness! Even in that tremendous hour, I had a consciousness of the dignity of suffering – suffering, that is, which comes from the height of heaven above, and not from the depths of crime below! I resolved that the lamp of my life's joy should go out without a sigh audible to human ears, save hers alone, who had lit that pure flame in the black night of my existence.

"Lilias, I enter into no detail of what I felt in that momentous crisis, for you have no woman's heart if you have not understood it, in its uttermost extent of misery. One thought, however, stood up pre-eminent in that chaos of suffering – the conviction that I must not see Aletheia Randolph again, or the very powers of my mind would give way in the struggle that must ensue. This thought, and one other – one solitary gleam of dreary comfort, that alone relieved the great darkness which had fallen upon me, were all that seemed distinct in my mind: that last mournful consolation was the resolution taken along with the vow to see her no more, that ere I passed forever from her memory, she should know what was the love with which I loved her.

"Quietly I gave her father my hand when I quitted him, and he said, 'We shall meet in the evening;' my own determination was never to look upon his face again. I went home, and sitting down, I wrote to Aletheia a letter, in which all the pent-up feelings of the deep, silent devotion I cherished for her, were poured out in words to which the wretchedness of my position gave a fearful intensity – burning words, indeed! She has told me since, that they seemed to eat into her heart like fire. I left the letter for her and quitted the house; and I believed my feet should never pass that beloved threshold again. There was a spot where Aletheia and I had gone almost day by day to wander, since we had dwelt in that land. She loved it, because she could look out over the ocean in its boundlessness, whose aspect soothed her, she said, as with a promise of eternity. It was a huge rock that rose perpendicularly from the sea, and sloped down on the other side, by a gentle declivity, to the plain. I have often thought what a type of our life it was; we saw nothing of the precipice as we ascended the soft and verdant mount, and suddenly it was at our feet, and if the blast of heaven had driven us another step, it had been into destruction.

"Thither, when I had parted, as I believed, forever, with that darling of my heart, I went with what intent I know not: it was not to commit suicide; although in that form, in the mad longing for it, the curse of my family has ever declared itself. I was yet sane, and my soul acknowledged and abhorred the tremendous guilt of that mysterious crime, wherein the created dashes back the life once given, in the very face of the Creator; not for suicide I went, yet, Lilias, as I stood within an inch of death, and looked down on the placid waters that had so swiftly cooled the burning anguish of my heart and brain, I felt, in the intense desire to terminate my life, and in that desire resisted, a more stinging pain than any which my bitter term of years has ever offered me. Oh, how shall I tell you what followed? I feel as though I could not: and briefly, and, indeed, incoherently, must I speak; for on the next hour – the supreme, the crowning hour of all my life – my spirit enters not, without an intensity of feeling which well-nigh paralyzes every faculty.

"I stood there, and suddenly I heard a sound – a soft, breathing sound, as of a gentle fawn wearied in some steep ascent – a sound coming nearer and nearer, bringing with it ten thousand memories of hours and days that were to come no more: a step, light and tremulous, falling on the soft grass softly, and then a voice. – Oh, when mine ears are locked in death, shall I not hear it? – a voice uttering low and sweet, my well-known name. I turned, and when I saw that face, on whose sweet beauty other eyes should feed, yea, other lips caress, for one instant the curse of my forefather seemed upon me; my brain reeled, and I would have sprung from the precipice to die. But ere I could accomplish the sudden craving of this momentary frenzy, Aletheia, my own Aletheia, was at my feet, her clinging arms were round me, her lips were pressed upon my hands, and her voice – her sweet, dear voice – went sounding through my soul like a sudden prophecy of most unearthly joy, murmuring, 'Live, live for me, mine own forever!'

"Oh, Lilias, how can I attempt with human words to tell you of these things, so far beyond the power of language to express! I felt that what she said was true – that in some way, by some wonderful means, she was in very deed and truth, 'mine own, forever,' though, in that moment of supremest joy, no less firmly than in the hour of supremest sorrow by my mother's dying bed, my heart and soul were faithful to the vow then taken, that never on my desolate breast a wife should lay her head to rest. 'Mine own forever!' – as I looked down, and met the gaze of fathomless, unutterable love with which her tearful eyes were fastened full upon my own, I was as one who having long dwelt in darkest night, was blinded with the sudden glare of new returning day. I staggered back, and leant against the rock; faint and shivering I stretched out my hands on that beloved head, longing for the power to bless her, and said, 'Oh, Aletheia, what is it you have said: have you forgotten who and what I am!'