Images de page

made the comparatively new and central idea of these lectures sufficiently clear to the minds of our readers. If they have grasped for themselves the conception of heat as molecular motion, they will be able, by a little reflection upon common things about them, to apply it in an almost endless variety of interesting ways. They will see, for example, that when mechanical force is brought to bear upon different forms of matter, a struggle takes place between their ultimate particles through their natural cohesion, or force of gravitation, as it may be termed, towards each other. In one case, the limits being small, and the moving particles small, the motion is invisible, and can only be known by the heat given off, as in the case of the lead bullet struck by the hammer. In this case the vibration of the particles among themselves is a matter of conception and imagination. In another case the cohesion of the ultimate actions is slighter, and is so far modified, that a change takes place in the form of the body itself, a solid, for example, as ice, is changed into a liquid as water. In a third case, as in that of water, "the particles break the last fetter of cohesion, and fly asunder to form bubbles of vapour. Thus freed from the influence of cohesion, we have matter in vaporous or gaseous form.” Thus we have answered the question, what is heat ? The further application of this principle we must leave our readers to seek for themselves in the volume we are desirous of introducing to them. They will find there a full explanation of the interesting processes of expansion and combustion; and of the more difficult theory of calorific conduction and radiant heat. We have not space to allow of further information in that direction, but in what remains to us, we wish to direct attention from the earth to the sun. It is from the sun the earth derives its heat, but we are told that the amount of heat received by the earth is an inconceivable portion of what the sun is constantly giving forth. The total amount of heat emitted by the sun in a minute is capable of boiling 12,000 millions of cubic miles of ice-cold water. This statement does not help us much, except to produce the general sense of something inconceivably vast: and leads us to ask, where then does the sun obtain all this heat? It cannot be expending its capital, for it appears that if it were a solid globe of burning coal, in less than 5,000 years it would be all burned out. A conjectural answer has been given to the question as follows: and it derives additional interest from that was seen in our heavens a few weeks ago. For three or four hours during a November night, there fell an unbroken shower of brilliant stars : none of them, so far as we know, touched the earth. Coming toward us in great rapidity, they were raised by their motion to such a degree of incandescence, that before they reached us they were dissipated by their own heat. Now let it be supposed that the lens-shaped envelope which surrounds the sun, and which is known to astronomers, as the Zodiacal Light, be a crowd of meteors; if they are moving in a resisting medium, and with rapidity continually approaching to the sun, they will ultimately fall into it, and in a state of heat. Under these circumstances, they would be competent to produce the heat observed, and this would constitute a source from which the annual loss of heat would be made good. It is calculated that an asteroid, on striking the sun with a velocity of 390 miles a second, would develope more than 9,000 times the heat generated by the combustion of an equal asteroid of solid coal. This is only of one of many answers which have been suggested to this question. That they are but suggestions we need scarcely add. But this brings us back to the point from which we started. “Grand, however, and marvellous as are these questions regarding the physical constitution of the sun, they are but a portion of the wonders connected with our luminary. His relationship to life, is yet to be referred to. The earth's atmosphere contains carbonic acid, and the earth's surface bears living plants; the former is the nutriment of the latter. The planet apparently seizes the combined carbon and oxygen ; tears them asunder, storing up the carbon, and letting the oxygen go free. By no special force, different in quality from other forces, do plants exercise this power,—the real magician is the sun. We have seen how heat is consumed in forcing asunder the atoms and molecules of solids and liquids, converting itself into potential energy, which re-appeared as heat, when the attractions of the separated atoms were again allowed to come into play. Precisely the same considerations which we then applied to heat, we have now to apply to light; for it is at the expense of the solar light that the decomposition of the carbonic acid is effected. Without the sun the reduction cannot take place, and an amount of sunlight is consumed exactly equivalent to the molecular work accomplished. Thus trees are formed, thus the meadows grow, thus the flowers bloom. Let the solar rays fall upon a surface of sand, the sand is heated, and finally radiates away as much as it receives ; let the same rays fall upon a forest, the quantity of heat given back is less than is received, for the energy of a portion of the sunbeams is invested in the building of the trees. I have here a bundle of cotton, which I ignite; it bursts into flame, and yields a definite amount of heat; precisely that amount of heat was abstracted from the sun in order to form that bit of cotton. This is a representative case;—every tree, plant, or flower, grows and flourishes by the grace and bounty of the sun." (Pp. 430, 431.)


Englishmee passion forength, which pe still haunts. iki so ha

I WRITE in a cosy bedroom—a bright fire burning in the gratemy slippered feet resting on the softest of all possible cushions

-at my elbow a glass of mild wine-and-water, in which floats an almost transparent film of lemon peel-on the hob simmers a cup of beef-tea-in a word, I am confined to the house by a bad cold. After struggling down to the office for some weeks, and feebly essaying to go through my ordinary duties, I have been taken in hand by the powers that be, lest worse should come of it. Will the Editor of the CHRISTIAN SPECTATOR accept, in default of better, the fancies and vagaries of a sick room? A periodical which has admitted prelections on the Advantages of a bad temper and the Disadvantages of early rising may not turn up its nose at a disquisition on the compensations which attend my present condition.

Foreigners insist, with a fair measure of truth, that we Englishmen have no capacity 'for the enjoyment of a holiday. The passion for working at something with all our heart land soul and strength, which pervades our national life, and has built up our national greatness, still haunts us when we have nothing to do. The average Briton never works so hard as during holidays. I remember to have met a typical English paterfamilias in Rome during the height of summer. It was scorching noon-tide. The natives had all become comatose, dozing undershady colonnades, or idly gossipping in dimly-lighted chambers, from which every ray of sunlight had been carefully excluded. But our Englishman, mopping his moist brow and flushed cheeks with one hand, and holding his faithful Murray in the other, steadily persevered in “doing” the regulation sights through the blazing noon. Voila, Monsieur Jean Bull, I heard whispered by a party of French Zouaves who were passing. It was, indeed, Mr. John Bull, who, in true British fashion, was toiling through his annual holiday and enjoying hirself by working twice as hard as usual. A bad cold, however, or any similar slight ailment, brings with it a gentle languor and lassitude which, relaxing “those wrestling thews that throw the world,” reduces us to the level of ordinary mortals. We are able to enjoy the luxury of doing nothing. The kief of the Egyptians, the dolce far niente of Neapolitan Lazzaroni is mine. I lie back in my easy chair, and in slumbrous peace

as during hab in Rome The natividly gossipfit had bee

hinking years on the the Prophen

let the hours go by. Seated on the carpet of indolence, I smoke the pipe of peace beneath the canopy of repose. “Visions come and go”--there are no impertinent and obtrusive duties to interrupt them. “Gorgons and hydras and chimeras dire” fashion themselves between the bars of the grate. Stately pageants grow up out of the wall-paper, and epics are enacted amongst the bed-hangings. I have neither power nor desire to do anything save doze and dream through the perpetual afternoon* of my sick room. For a few days, at least, this new life of dreamy vacuity is very pleasant.

My worthy, but long-winded friend Borem, hearing that I was not well, has just called to inquire after me. He is a very respectable fellow, but terribly wordy, reminding me, in the length and tedium of his talk, of a famous Viennese professor, of whom Thomas Fuller exclaims, “What a gift had John Halsbach in tediousness ! who, being to expound the Prophet Isaiah to his auditors, read twenty-one years on the first chapter, and yet finished it not.” Thinking I might be glad to hear the news, he was shown up into my room. Before long, he had mounted his hobby, and was beginning to ride it hard. He has some special and peculiar light on the subject of the Horns in the prophecies of Daniel. He is never weary of expounding his own theory, or of confuting all existing theories, except his own. On the present occasion, he had just formed his line of battle for a general engagement with all gainsayers. I had fallen back in my chair with that feeling of weariness, despair, and irritation with which a bore, with a crotchet, always inspires me. · Already he had commenced the action by attacking Dr. Cumming with his heavy artillery; when suddenly he was “moved on” by the policewoman in charge. No excuse was offered. No courteous fiction was thought needful. He was simply told that much talking was not good for me, and so, sans phrase, he was morally collared and turned out of doors. I am afraid he caught the twinkle in my eye, which I could not repress, as he turned disconsolately from the room, looking, though not saying

“ Perhaps you did right to dissemble your love;

But why did you kick me down stairs ?" Is it no compensation, no consolation, to see boredom thus summarily arrested and executed without form of trial ?

As poor Borem disconsolately turned away, I felt elated by a new-born sense of importance. For some days I have had what

* “ In the afternoon they came unto a land

In which it seemed always afternoon.”—The Lotos Eaters.

octuch a degrlaw, and myhould not be impendi

Sir William Hamilton used to call “ a latent consciousness” that I was being made much of. Everything in the house was subordinated to my comfort and convenience. My room was becoming the centre of the household; attendance upon my wishes had insensibly grown to be the pivot around which all domestic arrangements were made to revolve. In my ordinary state, the fact that the children were asleep, or the servants were tired, or that the cataclysm of a monthly was impending, sufficed for a reason why this or that should not be done. Now, my faintest wish becomes law, and my comfort and convenience are consulted to such a degree that even Borem, from whom my wife has expectations, is turned out of doors, because it is perceived that his presence ruffles me. I discover that my indisposition has invested me with regal authority. My place in the household is no longer that of primus inter pares. I have grown to be autocratic. Even the wash, the due recurrence of which is fixed and immutable as an astronomical phenomenon, has been postponed “till Master is better.”

Since the day before yesterday, a great gulf has opened between me and the active life of the outer world. Up to that time, I was earnest and active not only in my own affairs, but in those of my neighbours. The Times was a daily necessity; I felt ruffled and ill-used if I did not get it in due course. It was essential to my comfort that I knew how the world wagged. Until I had seen the paper, I suffered from an uncomfortable suspicion that something had gone wrong-like a nervous passenger on the coach-box, who dares not remove his eyes from the reins, lest the driver should upset the coach. I flatter myself that I was not altogether mistaken in the estimate I formed of my services. Did not I prevent the levying of that additional farthing in the pound in the paving rate ? Did not I carry Smuggs for beadle at the head of the poll over seventeen other candidates? Who but I defeated that job about gilding the hands of the clock in the market-place? But to-day all these things are nothing to me. The echoes of the outer world fall muffled and faint upon my unregarding ears. Like the thin ghosts of Virgil's heroes, or the disembodied spirits of the Schoolmen, I hear from afar the movements of the busy world, but I take slight interest therein. I smile languidly at the eager excitement they once stirred within me. It is far more important that my barley-water be sweetened and acidulated to the right point, than that the nefarious designs of Tompkins be exposed in the Board of Guardians, or that the schemes of Bismarck should be rightly understood. Emerson, in one of his Essays, describes a man coming out of a crowded and excited public meeting, into the calm still night. Beneath the silent stars, and the broad full moon, Nature

« PrécédentContinuer »