solid stratum. Savages are in the habit of putting their ear to the ground to ascertain if their foes are approaching; and, in the whispering gallery of St. Paul's Cathedral, London, a person may hear the softest whisper apparently uttered in a much louder voice, although he is standing at a distance of 140 feet from the speaker. The mode in which sound is produced has been repeatedly demonstrated by actual experiment. If a spiral spring be struck, a vibration is produced which may be readily distinguished by applying the end of the finger or the finger-nail to it. This vibration causes an impulse in the air, which yielding to its pressure, a condensation or compression is produced, and a corresponding rarefaction on its opposite side, the spring immediately returns to its former position, and passes to nearly as great a distance on the opposite side (friction and the resistance of the air preventing it from going quite so far), and, in accordance with a well known axiom in mechanical philosophy, the position of the air is also changed, that space which before had contained rarefied air, is occupied with condensed air, and vice versa. The condensed air instantly expands, and communicates an impulse to the air next in contact with it, which process is repeated until the successive impulses thus produced are transmitted to the tympanum or drum of the ear, and the mind thus receives the idea or impression which we call sound. This effect may be produced by various means: a bell, or a tuning-fork being struck, causes a tremulous motion, or a succession of vibrations in the air. And on the organs of the voice, a musical pipe, or any other description of wind instrument, the effect is the same, the column of air vibrating and communicating its motion from side to side throughout the length of the tube. If the string of a pianoforte be struck, it is drawn out of the right line which it previously formed, producing compression on one side, and rarefaction on the opposite, which by the recoil of the string is repeated; and, as already shown, this effect is transmitted to the surrounding atmosphere, until, by friction and the resistance of the air, the string arrives at a state of rest. The vibrations of a musical spring, or other sounding body, are nearly isochronous; and it appears, from recent experiments, that the nearer perfect isochronism can be obtained, the more superior will be the quality of tone. If the vibrations do not amount to at least thirty per second, the ear is incapable of distinguishing tone. In proportion as the number of vibrations or beats which are performed in a certain time, are greater or less, so is the difference which we express by saying that one is higher or lower than the other. That which we call highest has the greatest number of vibrations in the same time, and that which we call lowest has the least. By an ingenious invention, a mode of counting the vibrations has been introduced, so that we can now with ease effect that which there was formerly great difficulty if not impossibility in accomplishing, we can now have one fixed uniform standard of sound, and transmit to a correspondent, at any distance of place, or of time, the exact type of any musical sound we may desire. By the aid of this invention, it has been ascertained that the C of the Philharmonic Society consists of 506 vibrations or beats in the second. The continental C consists of 520 beats,-as 512 is so nearly the mean between 506 and 520, that its difference can scarcely be detected by the most accurate ear; and as that number affords facilities for subdivision down to unity, it is now becoming extensively adopted as a standard, an improvement which will be appreciated by practical musicians, especially those who occasionally have to do with continental music. The velocity of sound is not nearly so great as the velocity of light; this may be proved by standing at a distance from a gun when it is fired, the flash may be seen considerably before the report is heard. Sir John Herschell, from the mean of the best experiments, has determined the velocity of sound to be 1125 feet per second, the temperature of the atmosphere being 62° of Fahrenheit's thermometer; by this means the distance or vicinity of a thunder storm may be readily calculated, as we have only to observe the interval between the flash and the report, and allow four seconds and a half for every mile, or 1125 feet per second, and by the same means the distance at which heavy ordinance is being fired may be accurately ascertained; a difference of temperature will however affect the velocity, as at the temperature of the freezing point, or 32o, the velocity is 35 feet per second less, or 1090 feet per second, but the temperature being known, it is easy to make the necessary allowance. What an evidence of creative design is here afforded us. How wondrous is the skill of the great artificer, by whom effects so complex and intricate are accomplished by means so simple, yet so universal! Throughout the domain of nature, so far as the limits of our observation can extend, we find one simple and universal mode by which we are rendered accessible to the sensation of sound, and all its important consequences in the economy of our existence. Thus, by the most simple means, effects the most various and diversified are accomplished. By its agency, speech, the power of communicating to our fellow man, the emotions and the passions by which our minds are actuated, is possessed. By its means are we alive to the influence of music-by its means are we aware of the deafening roar of the cataract, the terrible roll of the foaming billow, or the thunder's awful voice. At one moment we listen with delight to the melodies of the feathered choir. Again we tremble at the devastating effects of the whirlwind's furious blast. One moment our senses are ravished and our feelings absorbed in ecstatic delight, by the harmonies from the "swelling choir." Again, we tremble as we acknowledge our own impotence, when "the God of glory thundereth," and the very foundations of the earth appear to be riven from their basis by the violence of the concussion. We hang with rapture on the lips of eloquence, while the noblest powers of our souls are aroused, to emulate deeds of philanthropy, of benevolence, and of worth. We tremble as we listen to the hellish enginery of war belching forth its horrors, and our souls are sickened with the thought that one and another of our fellow-beings have by the very act which accompanied its voice been hurled into eternity. How tremendous is the consideration that we shall have to give an account of the manner in which we have employed this agency; and that, by the exertion of this simple power, results so momentous in the relation of man to man are accomplished-results so fearful in his whole history are effected-results so important in the final destiny of created being are completed. ON INDECISION OF CHARACTER. Ir is difficult to conceive a more pitiable or contemptible state of existence than that of a man who indolently yields himself a prey to indecision and irresolution. In the ordinary affairs of life, this cast of character constantly subjects its possessor to vexation and trouble, and frequently to misery. Anxiety of mind is its inseparable attendant; for how can he be at rest who knows not what course of action he will pursue under any given circumstance; who is unable to say with what habit of mind any event that may happen will invest him-whose will is not under the direction of his judgment; who only progresses, because, by the immutable laws of Nature, he cannot remain totally inert and stationary, and who must necessarily, by this imbecility of mind, become the sport of circumstance, rather than be governed by any fixed principle of action? Let us imagine a character of this unfortunate cast, possessing a thirst for distinction. If his desire be for political renown, how uncertain, or rather, how impossible is his success! We will suppose that he purposes to ameliorate the condition of mankind, to ennoble his race by plans of philanthropy, and of sound and energetic policy. But his insidious enemy -indecision, arraying itself in the garb of an angel of light, instils into his mind that "in prudence lieth wisdom." This sound maxim becomes his bane, this wholesome precept becomes a poisonous fallacy to his wavering understanding. This prudence, (or to give it its proper appellation,) this irresolution, will not allow him to decide on any of the manifold plans which his reason suggests, and his time is consequently consumed, and his opportunities of usefulness wasted in idle speculations. He beholds, with vain regret, one, perhaps, of meaner powers, but of a more resolute character, step before him, snatch the proffered advantage from his feeble grasp, and reap the renown which he fondly expected to crown his own exertions. Or, if he have so much resolution, as by an astonishing effort, to determine on a particular course, and actually to commence a career, his evil genius still besets him; and, by throwing in doubts, fears, and misgivings, entirely paralyses his efforts, and prevents his success. If his predilection be towards the paths of literary fame, his irresolution presents an insuperable barrier to his advancement; for how can the man who is incapable of arriving at a fixed determination, presume to instruct others? In commerce he is equally unfortunate: while he is endeavouring to persuade himself that an opportunity of aggrandizement which occurs is such as he may prudently embrace, the time for action passes away, and he remains still the anxious and self-accusing prey of indecision. Like This distressing frame of mind induces inconsistency, and too frequently depravity of character, inasmuch as it weakens the mental stamina. the sand upon the sea-shore, to which each wave gives a different impress, the irresolute man is at the mercy of the world, which gives a different bias to his mind, as ambition, selfishness, philanthropy, or folly, touches its chords. Surely he, of all others, may exclaim, in reference to this mental debility, that "he knows not what a day may bring forth." In the concerns of religion, such a character is inconceivably unhappy. Whilst afraid to plunge into the vortex of the world's gratifications and pleasures, yet too imbecile to conform his actions to that which both his judgment and his conscience tell him to be the only path to peace and serenity of mind, he enjoys not the one, and is a stranger to the happiness resulting from a steady pursuance of the other. He experiences the remorse of the children of this world, without participating to any extent in their indulgences; he suffers the tribulation of virtue without its reward. A most serious effect likewise accrues in the loss of that self-respect which is so necessary to the proper government of a sentient and responsible being, in his intercourse with the world, and which is his due in his intellectual and moral capacity. Constant failures, and repeated proofs of incapacity, superinduce a peevish and fretful temperament, and are calculated to make life miserable, and its enjoyments distasteful; whilst the tormenting consciousness, that all this has befallen him from his inertness of will and culpable indecision, wears into and saps his vital energies. Every fresh instance of this infirmity decreases his capacity of volition; "unstable as water, he cannot excel." His own life is miserable, and its influence on those around him is unhappy; for he carries this wavering, inconstant, uncertain disposition with him into the smallest and commonest concerns of life. He is the sport of every passing wind; his friends cannot depend upon him, who can place no reliance on himself; his enemies (for this state of mind necessarily creates him many,) take advantage of it, and we may receive it as an axiom, that such a character cannot prosper in any thing that he undertakes. Let not any who peruse this paper imagine that it would be vain to attempt to eradicate this temper of mind; or suppose that it is one to which those who are afflicted with it must submit, as to a disease from which it is impossible to free themselves. Can we, for a moment, imagine it possible that man is sent forth from his Creator's hands, with all his faculties in a capacity for action, and yet with an irremediable curse of this kind clinging to him and rendering all his efforts abortive? No; it has its source in indolence, that bane to the developement of all our powers, whether of mind or body. It is curable, or rather, it is a disposition of mind which should never be contracted; and for which those who suffer themselves to become its prey will assuredly not be held guiltless. Let all, then, who feel the first approaches of this insidious, but fell destroyer, which, though sometimes assuming the garb of virtue, is alike destructive to man's happiness and prosperity, take a strong resolution to combat sloth in all its varied forms of approach, and never suffer their slightest resolve, when maturely considered, to remain unexecuted. The pious George Herbert's advice, though quaintly expressed, is sound: "When thou dost purpose aught within thy power, For, reader, be assured of this, that although prudence be commendable, and a modest humility of our own merits be a cardinal virtue, no great or good action, no honourable and praiseworthy achievement has ever been recorded of the irresolute waverer, the infirm of purpose:— "Who breaks his own bond, forfeiteth himself.” And how can we expect the man, who cannot keep faith with himself, to keep it with others, or become a benefactor to his species? AQUARIUS. ROUSSEAU'S OPINION ON THEATRICAL ENTERTAINMENTS. WE are aware that the character of Rousseau, judging it from his own unblushing "confessions," will not bear the slightest scrutiny, and that his example can never be held up for imitation. We know, too, that his writings, generally speaking, are distinguished alike for the dangerous notions they convey, in reference to the religious and social duties of mankind, as for the speciously delightful garb in which they are clothed. It must, nevertheless, be acknowledged, that he always wrote with an untrammelled spirit, and, indeed, seemed to delight in the singularity of the views he put forth, and in their opposition to generally-received opinions. Accordingly, in many instances, we find the practices and tastes of civilized society exposed with a force and ingenuity hardly paralleled. As an illustration, we present our readers with some extracts from his letter to D'Alembert, the celebrated French Encyclopædist, on "The Effects of Theatrical Entertainments on the Manners of Mankind," which contain, we apprehend, no small amount of truth. "Public entertainments are made for the people, and it is only by their effects on them that we can determine their absolute qualities. There may be an infinite variety of these entertainments, as there is an infinite variety of manners, constitutions, and characters of different nations. Nature is the same, I allow; but nature modified by religion, government, law, customs, prejudice, and climates, becomes so different from itself, that we must no longer inquire for what is suitable to man in general, but what is proper for him in such a place or country. Hence Menander's plays, which had been written for the Athenian stage, did not at all suit that of Rome; hence the shows of gladiators, which, in the times of the republic, used to inspire the Romans with courage, had no other effect, under the emperors, than to make those very Romans ferocious and cruel: from the same spectacle, exhibited at different times, the people learned at first to undervalue their own lives, and afterwards to sport with those of others. "With regard to the species of public entertainments, this must be determined, by the pleasure they afford, and not by their utility. If there is any utility to be obtained by them, well and good: but the chief intent is to please; and, provided the people are amused, this view is fulfilled. This alone will ever hinder these institutions from having all the advantages of which they are susceptible; and they must be greatly mistaken, who form an idea of perfection, which cannot be reduced to practice, without offending those whom we would willingly instruct. Hence ariseth the difference of entertainments according to the different character of nations. A people of an intrepid spirit, but determined and cruel, will have 'spectacles full of danger, where valour and resolution are most conspicuous. A hot fiery people are for bloodshed, for battles, for the indulging of sanguinary passions. A voluptuous nation wants music and dancing. A polite people require love and gallantry. A trifling people are for mirth and ridicule: trabit sua quemque voluptas. To please all these, the entertainments must encourage; whereas, in right reason, they ought to moderate their affections. "The stage in general is a picture of the human passions, the original of which is imprinted in every heart; but if the painter did not |