When a man confines himself to his own little locality, id looks around him on the subject earth, which his plastic and converts from a wilderness into a garden; or on the >wer animals, whom he subdues to his will, and causes, by le superiority of his mental powers, to supply his wants, and dminister to his comforts; or, even on the waters of the farpread ocean, whose proud waves he conquers, and over vhose trackless wastes he makes his way; or on the free and capricious air, whose fury he controls, and whose blandness he renders subservient to his pleasures or his profit,-in such contemplations he may find much to foster self-complacency, and to persuade him that he is, in reality, that lordly being which pride and vanity delight to portray. But the scenes which astronomy unfolds are altogether of a different tendency, and ought to repress those swellings of self-love, which a more partial and contracted view of his situation may excite. The voyager who has compassed the earth, when he returns to his native village, is surprised to find that every thing has, to his view, contracted in its dimensions, and become comparatively mean and sordid in its appearance. The houses have shrunk into hovels; the village-green, from a broad-spread lawn, has dwindled into a miserable courtyard; miles have diminished into furlongs; and magnificent estates into sorry farms. This effect has been produced by a contrast with the expansion of his own views, and a similar result arises, or, at least, ought to arise, from the contemplations of the astronomer. Expatiating in the infinity of the universe, the things of earth seem to lessen while he regards them. As he pursues his inquiries, the contrast becomes daily more apparent and more humbling. He begins to perceive an emptiness in those things that formerly engaged his attention, and interested his affections, which he did not previously suspect. He finds himself placed on a little planet, whose comparative insignificance is such, that, were it struck from the face of creation, its fate would be but like that of a fallen star, which loses itself in the heavens, and is remem bered no more. And, as to himself, what an atom is he! This is the But the mind cannot rest here. If the creation be so inconceivably extensive, what is the Creator? most interesting and elevating of all inquiries. mind has dwelt upon it, till its importance is appreciated, and its various bearings perceived, and then turns back upon itself, the reflection naturally occurs,' Am not I a child of this Almighty Parent? Is it not in His universe that I exist? Has he not constituted me a part of the system which His Infinite Wisdom has established? And what, then, is that system with reference to me, and the race with which I am connected? Such views open, to the inquiring mind, the whole field of Natural and Revealed Religion, and lead irresistibly to the conclusion, that there is no satisfactory account of man's nature and destiny, but in the inspired word, and no restingplace for his hopes, but in the life and immortality which have been brought to light in the Gospel of Jesus. FOURTH WEEK-TUESDAY. II. THE STARRY HEAVENS.-GRAVITATION AND INERTIA. If it be true, as there is every reason to believe, that the fixed stars, which sparkle in the heavens, are suns like our own, shining, as they certainly do, by their own light, and shedding their radiance on other worlds, a view of creation is unfolded to us, which it is both delightful and overwhelming to contemplate; and to this view we shall afterwards turn. At present let us take a rapid survey of the system of which we ourselves form a part. Our star (for the sun, considered with reference to the universe, deserves no higher name) appears larger than other stars to us, only on account of its nearness; but when we call it near, we speak relatively; for it is known to be separated from us by the amazing distance of 95,000,000 of miles. It is the centre of our planetary system; that is to say, there are certain bodies similar to our own globe, which bear to the sun the same relation, being, like the earth, attracted to it by the all-pervading law of gravitation, and only kept from falling into it, as a stone when thrown falls to the ground,-by the velocity with which they move in a different direction. The two well-known laws, so simple in their nature, and yet so vast in their effects, by which the whole creation is moulded and regulated, have, ever since their discovery as universal agents, been most justly regarded with the highest admiration; and it is not easy to conceive any thing capable of impressing on the mind a more exalted view of the power and wisdom of the Creator. It would be inconsistent with our plan to enter deeply into this subject; but some cursory observations on a matter of such intense interest, and so directly illustrative of the perfections of God, cannot be considered out of place. Every one is familiar with the law of gravity or weight, that mysterious power, which, acting uniformly, draws all things downwards, towards the centre of the earth. It is in virtue of this law, that, were I to open my fingers, the pen with which I write would fall flat upon the paper. It is the same law which causes the ink to flow upon the paper from my pen, the paper to lie steadily on my desk, and the desk itself to stand firmly on the floor. Nay, it is this very law which gives solidity to the ground on which I tread, which has formed it into a globe, and which prevents it from breaking up into shapeless and unconnected masses. properties of this unseen agent are too palpable, in relation to sphere, to have escaped the attention of the earliest inquirers into nature. But it was reserved to a far later period to demonstrate, or even to conjecture, that the very same power, which produces such salutary effects in the earth, is not only an essential property of all matter, but acts at the greatest distances, and preserves the balance of the uni our own verse. The The other property, which, combined with gravitation, is employed in regulating the machinery of creation on the great scale, is also familiar to the most ignorant, in regard to some of its qualities. Every child knows, that a stone thrown forcibly from the hand, or an arrow shot from a bow, will continue for some time to move forward in the direction in which it has been projected; but, then, this power of continued motion, as it comes under ordinary observation, is only very limited in its operation, because it is counteracted both by the attraction of the earth and the resistance of the air, and no force which human skill can apply, is sufficiently powerful to give an impetus to any body, capable of overcoming, for a length of time, these opposing forces. In the principle itself, however, there is no limit; and the law is simply this, that while a body at rest will, if not disturbed, remain for ever in that state, a body once set in motion, will, when not acted on by some modifying or counteracting force, move on continually without deviation or intermission, in a straight line. This is the law of inertia,-a law which is not less universal than that of gravitation. Now, to understand the operation of these two laws in relation to each other,-first, suppose a small body, placed at rest, in the neighbourhood of a large one, also at rest, both of them in empty space. The mutual attraction would immediately begin to operate, and they would move toward each other till they met, and that with a rapidity proportioned to the quantity of matter contained in each, the larger most powerfully attracting the smaller. Suppose, again, that the smaller body, instead of being placed at rest, was projected with a certain velocity in a direction different from that in which the other was situated. That velocity might be very great; and then, after a mutual disturbance, arising from the reciprocal attraction, the moving body would disengage itself from the other, and fly off into boundless space; or it might be very small, and then the vis inertia would be overcome, and the two bodies would fall towards each other, and unite; but, if the projecting force were, within certain limits, proportioned to the gravitating force, the consequence would be, that there would be a certain point in the progress of the moving body, in which the two powers would balance each other, and then that body would continue to move, indeed, but in a constant circuit round the attracting force, which would thus become its centre of motion, and its course would be in an oval or in a circle, according to the force and direction of the motion originally impressed. This is, in fact, the principle by which the whole planetary system is governed. The sun, a body of vast dimensions, is the centre of attraction to which all the planets gravitate, and into which they are prevented from falling only by the opposite power of inertia. The two forces, with the nicest exactness, balance each other; the former, in reference to this principle, being called the centripetal, and the latter the centrifugal motion; and thus the great machine is kept in action, and the planets wheel steadily in their respective orbits, and perform their various beneficent functions. I may add, that this is the principle, not of the solar system only, but of the system of the universe. 'O, unprofuse magnificence divine! O, wisdom truly perfect! thus to call From a few causes such a scheme of things,— Effects so various, beautiful, and great, An universe complete!' THOMSON. FOURTH WEEK-WEDNESDAY. III. THE STAURY HEAVENS. THE PLANETARY SYSTEM. In the account of the creation given by Moses, the heavenly bodies are spoken of merely with reference to the earth, and the living beings which were created to inhabit its surface. Any other view would have been altogether misplaced, and inconsistent with the design of Revelation. The words of the inspired writer, therefore, are, 'God said, let there be lights in the firmament of the heaven, to divide the day from the night; and let them be for signs, and for seasons, and for days, and for years; and let them be for lights in the firma |