LECTURE XII.

MORAL INFLUENCES OF THE WINDS.

ALLOW me to dwell for a moment on the sounds of the wind and the voices of nature, in their influence upon the spirit of man. There are intonations of the voices of nature, which exercise a controlling influence upon a meditative mind. They place him alone with nature and its Author, and naturally associate his thoughts with the past and the future.

The poetry of the ancients is beautiful and endearing, because they had ears exquisitely attuned to the perception of these voices. In this view you see the cause, why they surrounded their temples and tombs with forests. Still deeper associations are created by these sounds when heard from ancient and mouldering towers, the vaults of deserted cloisters, and the monuments of cities crumbling to ruins. Imagination hears them as the speech of time, uttering a lament over the memory of life, busy exultation, and gladness, which were once heard there and are now heard no more. It is said that in the north of Scotland, a country of storms, mountains, and ruins, the people have learned to increase the effect of such sounds, by suspending Eolian harps to the walls of ruined towers and the forest trees. These ærial sounds are heard to swell and die away, near at hand, retiring, or far in the distance, varying like the sweet modulations of the harmonica. The imaginative traveller easily supposes that he hears the bards of Ossian discoursing from their clouds of their wars and loves, and of the memory of their joys that are past.

Antiquity offers similar examples. The walls of Thebes were in this way harmonious; and the statue of Memnon appeared to become animated by the first rays of the morn

ing., The Chinese, in particular, have carried the art of varying the modulations of the wind, in the form of harmony, to the highest degree of perfection. By harmonic illusions of this sort, they give an air of enchantment to their voluptuous gardens. Sometimes the agitated earth trembles under the feet of the listener. Terrible sounds, and the groans of pain, are heard. The visitant imagines, that he hears the cries of combatants, the neighing of steeds, and the sound of the trumpet. Sometimes along the walks of a smiling valley, the song of birds mingles with the sound of a rustic flute. Sometimes rocks appear in the distance, enveloped with mist, and bordered with arid sands. The traveller stops, and imagines he hears the roar of the sea in a tempest.

What a diversity of sentiments even the natural movements and sounds of the atmosphere, constituting, if I may so express it, the voluntary of nature, are capable of inspiring! The mariner, returning to his natal fields, walks beside the waving grain. The movement of the breeze upon the wheat fields, seems to his eye as it waves along the changeable verdure, as the ripple of the sea when gently agitated. The tempests, the waves, the perils, the far countries, all return to his thoughts.

Burning under the ardors of the sun, the traveller turns from the dusty road, and courts the shelter of the aspen shade. While the zephyr fans his temples and stirs the rustling foliage, half lulled to sleep, he imagines that he hears the brawling of the spring near the spot where he was born. But none of these voices of nature so readily evoke solemn thought, as the noise of a storm swelling and dying away in the tops of a wide pine forest, when heard from our bed in a night of rain and tempest.

Poets have often found a theme in painting the mixed associations of joy and sadness, called forth from the shadowy halls of thought and memory, in listening to this music of nature. They have yet to explain, in their songs, the harmony of these phenomena with the heart, both in its extremes of joy and sadness. The same sounds, the same

verdure, the same blithe vernal splendor of nature, which animate the youthful sports and dances of the young inhabitants of the country, impart matter of melancholy musing to the hoary senior, who is seeking the green tree under which he would wish to take his last sleep. The same rustling of the leaves that lulls and charms a cheerful spirit, inspires revery and sadness in one that is sorrowful.

It belongs to the poet to yield himself to these grand spectacles, these inspiring sounds. These voices, these aspects, are the sources of his sublimest inspiration. Schiller, like all poets of a high order, loved to meditate upon the arid rocks of the mountains. In the midst of a storm, he was often seen to throw himself into a boat, and abandon himself to the dashing waves of the Elbe. He felt his thoughts rise with the increasing fury of the storm; and his conceptions swelled with the roar of the tempest. He saluted these aspects of nature, in her terrors, with cries of gladness; and an inexpressible joy pervaded his mind.

There are people who pass their whole lives amidst these exciting spectacles and sounds. Goldsmith has faithfully depicted the peaceful Swiss exulting amidst his rocks and mountains:

Dear is the shed to which his soul conforms,
And dear the hill that lifts him to the storms;
And as the child, whom scaring sounds molest,
Clings close and closer to the mother's breast,
So the loud torrent, and the tempest's roar,
But bind him to his native mountains more.'

In the midst of the deserts, the Arab leads a wandering and exposed life. The aspect of a flowering Oasis, an isle of verdure in the burning sands, indemnifies him for fatigue, hunger, thirst, and danger. But he soon wearies of the cool fountain, the verdure, and shade; and he resumes his adventurous journeys across the ocean of sand, where the tempest brings no rain, the wind no coolness, and the burning sky is tempered by no clouds.

The red man of the American forest sleeps soundest,

when cradled by the roar of storms; proud in the consciousness how little he depends on any thing but himself. The boundless range of woods is his home; and it is only among fields and harvests that he feels himself a stranger. Nature bids him be strong or die, and he feels that in spirit he is strong. He loves the woods, for they are desolate, like himself.

In the severe and wintry climates of the polar regions, enveloped in perpetual fog, or beaten with incessant tempest, the inhabitants love their ice, storms, and rocks, and the hoarse roar of the storm-driven surge. They find happiness in the contemplation of these stern and awful scenes, and perpetual food for courage in daring to encounter, and learning to conquer them. The souls of their heroes, in the ancient days, swelled with no higher aspiration than after death to incorporate with the storms, and to return to behold their posterity from their clouds. Ossian, bard of melancholy, what dost thou, sitting on the stone of tombs ? Art thou dwelling on the memory of heroes that are no more? I hear the sad tones of thy harp. Thy kindred shades, leaning from the misty halls of their ærial palaces, listen with joy. Malvina, pouring her dirge for the loss of Oscar, acThe funereal burden companies the strain with her voice.

of her song is, 'the spring will come without renewing my vernal days. I vanish, like the mist of the hills. The warrior will search for me on the green heights, but will not find me.'

Such are the influences of the voices of nature, as depicted by the Caledonian bard. Thus he consoles himself for the loss of children that are no more. The grass waving on their tombs, or rustling in the breeze, recals the memory of his forefathers, and the distant roar of storms awakens the thoughts of his youth. Who has not been aroused to feel the musing sadness, connected with the memory of those who are no more, by these voices of nature? The soul instinctively attaches itself to such thoughts; for they are associated with immortal hopes, and with the eternity of the past and the future.

LECTURE XIII.

WEIGHT OF THE ATMOSPHERE.

In briefly discussing the weight of the air, I shall recall to your recollection some of the most extraordinary and beautiful phenomena of physics. Let us weigh the air with Galileo, Torricelli, and Pascal, who first demonstrated that it has weight. To the discovery of the weight of the atmosphere, we owe the most useful of pneumatic machines, the air pump and the barometer. The pressure which the air exerts upon a man of ordinary size has been calculated, and found to amount to thirty-three thousand, six hundred pounds. It is a fact worthy of admiration. The air, introduced into our lungs by respiration, is sufficient to maintain the equilibrium, and to sustain us without a sense of pressure under this enormous weight. If the air could be entirely exhausted from our bodies by the air-pump, the internal resistance to this great external pressure being removed, our bodies would be crushed like a potter's vessel. The ancients denied the pressure of the air, though sustaining it at the very moment of denial.

The barometer is a graduated glass tube, hermetically sealed at one end and open at the other. It is filled with liquid mercury, which has been carefully boiled to deprive it entirely of air and humidity. Putting the finger upon the orifice, the tube is inverted. The finger being withdrawn from the orifice, the mercury descends in the tube to the height of about twenty-eight inches. At that height it is sustained by the pressure of the atmosphere on the bottom of the tube. You easily comprehend the cause of this phenomenon, and that it exactly indicates the pressure of a column of air, of the same dimensions with that of the mercury in the tube, to the height of the atmosphere.

If the weight of the atmosphere from any cause dimin