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We are now in a position to understand why a stone, thrown into the air, soon falls again. Obviously, because the great mass of the earth exerts a strong attraction upon it. It is no doubt true that this attraction is mutual, that the stone, in its turn, attracts the earth with an equal force, and accordingly we might expect to see the earth rising to meet it as it falls. But it must be remembered that the space through which the earth moves, in obedience to this attraction, is small in proportion as the earth itself is large. Hence it is imperceptible.
The attraction of the earth, generally spoken of as gravity, acts powerfully on all terrestrial objects. By it our houses, our goods, our cattle, and even our own bodies, are made to rest firmly on the ground, instead of flying off into empty space. But for it, bodies would have no weight, for their weight is simply the force with which the earth attracts them. Thus, as if by an invisible chain, held by an invisible, but Almighty hand, we are bound to the world given us for a habitation; and not only so, but the whole frame of nature is linked together by the same all-pervading influence, by which also the motions of all its parts are directed and controlled.
QUESTIONS FOR EXAMINATION.
What is matter? What is its opposite? Name some of the general properties of matter. What is meant by impenetrability? Give an example of impenetrability in liquids, in gases, in solids. Explain compressibility, dilatability, contractibility. Give examples of each. On what other property do these last mentioned properties depend? Explain the term density. Is matter supposed to be infinitely divisible? Is there any practical limit to its divisibility, and if so, what is it? In what class of substances has artificial division been carried farthest? Give an example. What is meant by inertia? Why does a rolling stone stop? Give an example of inertia as it effects living bodies. What counteracts inertia? What are the several effects which a force may produce? When does it not produce motion? What is the subject of KaturalPhilosophy? Give examples of different kinds of force. Of what use is friction? What is cohesion? Of what use is it? What is the attraction of gravitation? How is it affected by distance? by mass? Mention some of its effects at the earth's surface, and in the heavens.
[samuel Rogers, a distinguished poet, was born near London in 1762, and died in 1855. He was trained as a banker, which profession he continued to pursue through life. His writings are remarkable for elegance of diction, purity of taste, and beauty of sentiment. His larger works are, "The Pleasures of Memory," "Human Life," "Columbus," and " Italy."]
The lark has sung his carol in the sky;
The bees have hummed their noontide lullaby;
Still in the vale the village-bells ring round,
Still in Llewellyn-hall the jests resound;
For now the caudle-cup is circling there,
Now, glad at heart, the gossips breathe their prayer,
And crowding stop the cradle to admire
The babe, the sleeping image of his sire.
A few short years—and then these sounds shall hail
And soon again shall music swell the breeze;
And once, alas! nor in a distant hour,
When by his children borne, and from his door
Slowly departing to return no more,
He rests in holy earth with them that went before.
And such is human life;—so gliding on,
THE VOICE OF THE SHELL.
I have seen
THE VISION OF MIKZA.
On the fifth day of the moon, which I always keep holy, after having washed myself and offered up my morning devotions, I ascended the high hills of Bagdad, in order to pass the rest of the day' in meditation and prayer. As I was airing myself on the tops of the mountains, I fell into a profound contemplation' on the vanity of human life; and passing from one thought to another, "Surely," said I, "man is but a shadow, and life' a dream." Whilst I was thus musing, the Genius who haunts the mountain' came to me, and, taking me by the hand, said, with a look of compassion and affability, "Mirza, I have heard thee in thy soliloquies; follow me."
He then led me to the highest pinnacle, and placing me on the top of it, "Cast thy eyes eastward," said he, "and tell me what thou seest." "I see," said I, "a huge valleyl and a prodigious tide of water rolling through it." "Tho valley that thou seest," said he, "is the Vale of Misery, and the tide of water that thou seest' is part of the great Tide of Eternity." "What is the reason," said I, "that the tide that I see' rises out of a thick mist at one end, and again loses itself' in a thick mist at the other?" "What thou seest," said he, "is that portion of Eternity' which is called time, measured out by the sun, and reaching from the beginning of the world' to its consummation. Examine now this sea, and tell me' what thou discoverest in it." "I see a bridge," said I, "standing in the midst of the tide." "The bridge thou seest," said he, "is human Life; consider it attentively." Upon a more leisurely survey of it, I found that it consisted of threescore and ten entire arches, with several broken arches, which, added to those that were entire, made up the number about a hundred. As I was counting the arches, the Genius told me' that this bridge consisted at first of a thousand arches, but that a great flood swept away the rest, and left the bridge in the ruinous condition I now beheld it. "But tell me further," said he, "what discoverest thou on it." "I see multitudes of people passing over it," said I, "and a black cloud' hanging on each end of it." As I looked more attentively, I saw several of the passengers dropping through the bridge' into the great tide that flowed underneath it; and upon further examination, perceived there were innumerable trap-doors that lay concealed in the bridge, which the passengers no sooner trod uponl than they fell through them into the tide, and immediately disappeared. These hidden pitfalls' were set very thick at the entrance of the bridge, so that throngs of people' no sooner broke through the cloud' than many fell
into them. They grew thinner towards the middle, but multiplied and lay closer together! towards the end of the arches that were entire. There were indeed some persons, but their number was very small, that continued a kind of hobbling march' on the broken arches, but fell through' one after another, being quite tired and spent' with so long a walk.
I passed some time' in the contemplation of this wonderful structure, and the variety of objects which it presented; and as I looked, my heart was filled with a deep melancholy. "Alas," said I, "man' was made in vain! How is he given away to misery and mortality!" The G&nius, being moved with compassion towards me, bid me quit so uncomfortable a prospect. "Look no more," said he, "on man in the first stage of his existence, in his setting out for eternity; but cast thine eye on that thick mist' into which the tide bears the several generations of mortals that fall into it." I directed my sight' as I was ordered, and (whether or no the good Genius' strengthened it with any supernatural force, or dissipated part of the mist' that was before too thick for the eye to penetrate) I saw the valley opening at the further end, and spreading forth into an immense ocean, that had a huge rock of adamant' running through the midst of it, and dividing it into two equal parts. The clouds still rested on one half of it, insomuch' that I could discover nothing in it; but the other appeared to me a vast ocean' planted with innumerable Islands, that were covered with fruits and flowers, and interwoven with a thousand little shining seas' that ran among them. I could see persons' dressed in glorious habits, with garlands upon their heads, passing among the trees, lying down by the sides of fountains, or resting on beds of flowers; and could hear a confused harmony of singing birds, falling waters, human voices, and musical instruments. Gladness grew in me' upon the discovery of so delightful a scene. I wished for the wings of an eagle' that I might fly away' to those happy seats. But the Genius told me' that there was no passage to them, except through the gates of death' that I saw opening every moment upon the bridge.