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ON THE PERPETUATION OF PLANTS. The essential protection which the calyx affords, The care which the Creator has bestowed on the by enveloping everything while yet in a tender state, perpetuation of plants offers a wide field of inquiry. must not be forgotten; apt as we are to look on it as The collateral as well as the direct means of propa- a superfluous part, from attending only to the exgation are very numerous, and the results very ex- panded flower. It would be endless to point out the tensive and valuable.
numerous forms and modes under which it guards The circumstance which is, perhaps, most striking the unopened flower, and above all from the access in the mode of propagation by seeds, is the apparent of water. The calyx of the rose, so useless when anxiety for their production, in the means adopted. expanded, is a familiar instance of protection afforded This is less sensible to common observation, where by a structure which, compared to the purpose, is the magnitude, the duration, and the uses of the very inartificial ; and yet in this, and all similar plant itself, are conspicuous; but it becomes striking forms, that protection is complete. In the cistus, in the smaller and more perishable ones, and is often possessing a flower of unusual tenderness and delivery remarkable in the lowest parts of the scale. cacy, a varnish is superadded, for the purpose of Thus in the oak, we pay little attention to the pro- warding off the rains. The monophyllous calyces duction of seeds; or if noting it, we still know that present a structure more apparently efficacious, yet there is before us a being, destined to a life of so the protection is not more complete. And if the many centuries, that we scarcely think of its death, scale calyces of the grasses offer a much simpler or of the necessity of a system of perpetuation. contrivance, the security which they afford is not the
It is in the biennial and the annual plants that this less perfect. The calyx of the poppy is lax, and not anxiety for the continuation of the races is most very firmly closed; but as a counterbalance to this, obvious to common observation. Millions of indi- the flower bud is bent down by a curvature of the viduals seem to be utterly worthless : and there are stem, and erects itself only when the protection of even species without end, for which we can discover this deciduous guard is no longer wanted. The obno use, though desirous to find at least an insect stinacy with which this bud refuses to flower till it attached to each. Amid the hundreds of lichens and can erect itself, belongs to a still more interesting mosses, a very few would, as far as we can see, have circumstance in the physiology of plants: but under fulfilled the purpose which they appear solely to the present view, the inverted position enables the serve, in producing soils on naked surfaces. Yet in back of the calyx to ward off that water which these we trace the same care and the same anxiety. might have penetrated the less perfect junction at the The annual seems to grow for no other purpose than summit. to produce seeds; and that being accomplished, it That provision may here be pointed out in the dies. For this it struggles against every difficulty: | liliaceous flowers, which, as a sheath, forms the suband under every check, every accident, every mutila- stitute for the absent calyx, while the leaves also are tion, it still labours for this end, as if it were a con. sometimes arranged to perform the needful function. scious agent. We cut off its flowers, or cut down Under many different modes, the tulip, the genus itself, obstruet, impede it, in every manner, but it Allium, the grasses, and far more, will afford examples still resists, proceeding with an obstinacy of deter- of protection, given either to supply the want of a mination to effect this great object; while if, tired of calyx, or to add to the security which that affords. opposing it, we cease, it recommences, and having at And thus the seeds of the mosses are so embosomed length gained its purpose, dies. We can often even in the plant, at first, as almost to elude the botanist; prolong the annual life for another year, or more, by while they escape the chance of injury; to be elevated the same opposition; as if it was determined not to for dispersation, only when all hazard of failure is part with existence till it had obeyed its orders and past. fulfilled its destiny.
It is under all this care and concealment, that the The first mark of care, if a remote one, is found essential parts, destined to produce the perfect seed, in the contrivances for protecting the future flower are growing within; free from all hazard, till the ex. through the Winter, wherever such protection is ne- panding flower opens to the light that the work may cessary. In the buds, the beautiful packing, the be completed. And then do we begin to perceive investing scales, the down or hairs in some cases, and the utility of many other preparations towards this the varnish in others, are familiar: and; by these great end, the purposes of wbich we might not have contrivances, aided by that vital power, the action of understood before, and which he who looks on this which in resisting cold has not been explained, the interesting part of creation with a common eye, never most complete protection is afforded. In the bul. The vanity of philosophy may smile, if it bous-rooted plants, the bud is not less effectually pleases, at what it may choose to term fanaticism, protected beneath the ground, partly by the depth of but it is he who seeks for the hand of the Creator in earth, and partly by the singular chemical properties every one of His works, who has found the true clue of the coverings, aided by the same resisting vitality of investigation ; since the purpose is that clue, and,
In other cases, the flower bud is not produced that to study the design and the Designer, are one. till the frosts are passed; and our attention may now And if the care of a parent for its offspring, the ar.. be directed to the provisions within it for the forma- ticipations, the preparations, the watchfuiness o'i a tion and ripening of the seeds. In a certain sense, mother, are objects of our admiration, shall we not indeed, the flower is a superfluity, an example of at least investigate the contrivances, the thoug it, the gratuitous beauty, while it also contains provisions anxiety, of the Great Parent of all, for the safety, for the feeding of insects; yet with these are always and the life of these, His beautiful, but His lowest combined some uses for the seed itself, as, in many children; not inquire of his care for their fierpetuit y, cases, they are so numerous and remarkable that that not one shall be lost ? Could more have been they cannot be overlooked. The reader need only be done; and if He has not done it, by whrm then was reminded of the various ways in which they protect it effected ? Who is it that contrived, who is it that the essential parts of the fructification, the stamina, watches over the lilies of the field, that v.oť one of them and the pistils, on which the future seed depends ; should perish from his land? Who is it that g aards and of the contrivances for bringing the pollen into to maturity, even the minutest moss, and ens ares it contact with the latter.
a posterity, that it shall not fail from the mr Atitude
Fig. 3. A
of His children, who, even in the vegetable world, simplest construction, but possessing the disadvantage look to Him for their food, their life, and their enjoy- of reflecting an inverted image. ment? Was it He: and is it He who cares not for But the inversion can be corrected by taking a little man, provides not for him, governs him not, watches more pains. Let A be a him not? Be it so, if it can afford satisfaction to piece of looking-glass fixthink that so it is : but it will not be so to him who ed in a wooden or brass will open
his eyes on the world around him, and who frame, and connected has learned, in everything, to look to the Cause, the with a pieceof clear glass, Parent, of the universe. Would that I could per- B, so that the angle C B A suade him who has hitherto walked through creation shall be an angle of one without eyes, without thought, without a heart, to hundred and thirty-five take into his hand the first flower that shall present degrees, the image of an
Fig. 2. itself, and examine it as the work of some Being at object placed at F will be reflected from the lookleast who intended, and wrought, and cared. If elo- ing-glass at A, and proceed to the clear glass at B: quence has long done its worst for this unfortunate from this it will be reflected upwards to the eye at cause, there must be one who can sit down with the G, and the glass being transparent, the image and next flower that meets him in his Summer walk, and the hand will be seen at the same time; in this case ask himself, Whence came this, why is it here, why the image is erect. But, in general, neither of these all this beauty, why all this care? I have seen it plans are resorted to, for in both cases, as there are rise from a minute seed, I trace a series of cares and two reflecting surfaces from the glass, there will necontrivances that seed shall spring from it again, I cessarily be two reflected images, one of them certrace these under a thousand forms, I marvel at their tainly much less vivid than the other, but still suffiingenuity and their wisdom, I am astonished at an ciently visible to distract the eye anxiety which has neglected nothing, I see that an The optical portion of the Camera Lucida which end was intended, and I find that end attained. is usually sold consists of a prism, What more does man ever do to attain his objects, Fig. 3 is a section of the prism emwhen does he labour with more care and more know- ployed; the angle A is equal to 22} ledge, and when does he succeed with more certainty? degrees, c to 135 degrees, D 22 deDoes woman show more anxiety, more contrivance, grees, and B is a right angle of 90 for her offspring, than the Parent of this little flower degrees. The solid nature of the prism has displayed ? And who can that careful, that will not allow the hand to be seen through its thick. affectionate parent be? No one ! Even so was it ness, and the instrument is used in a different manner no one that reared me from helplessness to maturity, to the last contrivance. A is the I knew no parent's thought, no mother's care : there prism, B a moveable piece of brass, is no God. Can such a conclusion ever have entered having a small eye-hole in it at B; the heart of man? We know not how to believe him the reflected ray from c is received who has declared it.
near to this corner of the prism, [Abridged from MacCulloch's Proofs and Illustrations
and reflected upwards to the eye;
the eye-hole is so adjusted that
hand and pencil can be seen. In using the instrument THE CAMERA LUCIDA.
a vast deal depends on the proper adjustment of this The Camera Lucida, an invention of Dr. Wollaston, eye-hole. like the Camera Obscura, is an instrument employed If the light is very powerful on the object, and in making copies of drawings, and in portraying much less so on the paper, the part of the prism distant objects; but it is of greater service than the exposed through the hole should be small
, and the Camera Obscura, being much more portable, and, if opening through which the paper is seen large in properly used, reflecting the image of the object with proportion. On the other hand, if the light on the out the least distortion.
drawing is weak, a larger part of the prism must be If a piece of thin glass is held at an angle of forty- uncovered. In copying a print, great care must be ive degrees with the horizon, at a small distance taken that the print itself is perfectly flat and perfrom the table, and a sheet of white paper is placed pendicular to the horizon, and that the side of the immediately beneath it, the reflected image of an object prism at B A, fig. 3, which is opposite the print, before it will be visible, by looking downwards upon shall be parallel to it. If this is not attended to
, the it; and as the glass is transparent, the hand and print will be thrown into perspective and the copy pencil can also be seen, and an outline of the image distorted. can be made upon the paper. In this case the image If the object is to be copied of its natural size, its is inverted. Such an instrument as this can be distance from the prism in front must be equal to made off-hand very easily.
the distance from the eye to the paper; if it is to be Let B be a piece of thin
reduced it must be placed at a greater distance; if to plato-glass, about an inch
be enlarged, it must be brought nearer. and a quarter long, and
The Camera Lucida has been fixed to the eye-hole three-quarters of an inch
of a telescope or a microscope, in such a manner as wide; A a piece of wood in
to allow the objects within the field of vision to be which the glass is fixed, and
copied on paper. c a piece of pasteboard with a small hole in it, forming an eye-piece to keep the
LONDON: eye directed to one point.
JOHN WILLIAM PARKER, WEST STRAND. Let this little instrument
PUBLISHED IN WEEKLY NUMBERS, PRICE ONE PENNY, AND IN MONTHLY PARTI, be fixed on the top of a small stand, and you have a Camera Lucida of the
Sold by all Booksellers and Newsveaders in the Kingdom.
nothing too minute, nothing too numerous, for his notice;
that He who could create and arrange the whole, can also “When I consider thy heavens, the work of thy fingers; watch over and preserve the minutest parts of that whole. the moon and the stars, which thou hast ordained ;—what | Our notions of great and small are derived from our own is man, that thou art mindful of him ? and the son of man, imperfect experience, and strikingly show the limited scope that thou visitest him?"—Psalm viii., 3, 4.
of our minds. The distance of the sun from the earth is a When the inspired Psalmist gave utterance to these quantity so immense, as almost to perplex the mind which words, he was evidently under the intluence of those feelings reflects on it; and yet that distance is small, compared of awe, wonder, and admiration, which are sure to be ex- with the distance of the fixed stars :-again, the minutecited in every intelligent mind, by the splendid and sublime ness of the nerves and smaller blood-vessels of the human phenomena presented to us by the heavenly bodies. When body, is such as to require the microscope to aid us in an We consider ihe magnitude and the number of those bodies, examination of their structure, and yet there are other the immense distances which separate them one from entire animals, endowed with life and powers of motion, another, the almost inconceivable velocity with which they which are so minute that the eye cannot perceive them. move, and that those which we can see form, probably, but The words great and small, then, are for man's use; to the a very small part of the whole number;—when we revolve Almighty nothing is great, nothing is small; the revolving these things in our minds, we are naturally brought to planet, and the animalcule whose world is a drop of water, reflect on our own insignificance in the grand scheme of being equally objects of his ever-active care. This divinelycreation. If a man, after having applied to himself the sustaining power of Him, in whom “we live, and move, Fain and self-satisfying appellation of " lord of the creation," and have our being," is so obvious, that we may exclaim Were to remember that the glorious sun, and the planets with the poet Thomsonwhich revolve around it, form but one particular division,
Were every falt’ring tongue of man, class, or system in the universe,—that the earth is but an
Almighty Father ! silent in thy praise, bumble member of that system, and that he, man himself, Thy Works themselves would raise a general voice, is but a moving particle on the surface of this earth - he E'en in the depth of solitary woods may well be expected to give utterance to the sentiments
By human foot untrod ;-proclaim thy power, of David, and to wonder how the Great Deity can regard
And to the choir celestial Thee resound, with parental care so humble a member of so magnificent
Th' eternal cause, support, and end, of all !
Nothing is more calculated to elevate the mind, and to But this feeling, as Addison has beautifully shown, arises display to us the wonders of Creation, than the study of from the narrow powers of our own minds. 'We know that Astronomy. We propose, therefore, to place before our our perceptive faculties soon reach a boundary beyond readers a popular view of the elements, which serve for the which we cannot pass : we study the laws of Optics, but basis of the astronomer's study. In doing this, we need We know not the nature of Light:-we feel that we live not have recourse to the mathematical reasonings on which and think, but we know not what constitutes life and the various statements of the astronomer are founded; but thought. When, therefore, we judge of the Great Creator, we shall confine ourselves to such a simple explanation
of our own standard, we are lost in wonder at the vastness the Mechanism of the Heavens as may pave the way for and at the minuteness, as also at the countless number of the study of a more systematic treatise. We trust, therethe objects which are under the Divine protection. But fore, that both those who have, and those who have not, an When we consider God as an Omnipresent and Omniscient opportunity of referring to more elaborate works, will not
we then admit, indeed, that nothing is too vast, I find the following pages devoid of instruction, Vol. XII.
GENERAL APPEARANCE OF THE HEAVENS. It matters not what part of the world be chosen as the place
of experiment; the result is almost exactly the same etery Let us suppose a man to be totally ignorant of Astronomy, and to turn his attention from events occurring upon earth,
where, and the amount of the bending of the surface of to those which are presented by the heavens. He sees a
the ocean may be illustrated thus :—If we had a piece of brilliant and glowing body, the Sun, rise in the east, at
string four miles long, and were to apply both ends to the
surface of still water, and could possibly draw the string from four to eight o'clock in the morning, (according to the
into a perfectly straight line, the middle of the string would season of the year.) This body gradually attains a con
be about sixteen inches below the surface of the water; siderable altitude in the heavens, and continues to rise until month it then gradually descends, and in its descent, bends thus us wing that the water is not quite flat.
Thus might be supposed to arise the first conjecture that
the earth is round, like a ball; a fact which was clearly earth,) some time between four and eight o'clock in the afternoon. The spectator now loses sight of the glorious
proved by Captain Cook, who was the first to perform a orb, which does not again become visible for several hours; He left a given spot, and arrived again at that spot by an
voyage completely round the earth, about the year 1769. and when it does again appear, it is not at the point where it escaped from view, but at the opposite side of the heavens,
opposite course. There is an abundance of proof, derived
from other sources, that the earth is a globe; but those will namely, at the point where it first appeared on the preceding day. On watching the progress of the sun, he finds that
open upon us more plainly, as we advance.
We have hitherto endeavoured to trace what would prothe path, before noticed, is again travelled over by the
bably be the feelings and opinions of one who, without luminary, which becomes lost to his view, as before, in the west.
previous instruction in Astronomy, should note the appear. A third and fourth day the same phenomenon
ances presented by the sun. But that golden orb is not occurs; and the question naturally suggests itself to the observer's mind, "Is it the same cheering and dazzling
seen to be a solitary inhabitant of the sky: another lumi. visiter which I see day after day, or are they different
nous body about as large in apparent size as the sun, would
soon attract the notice of the gazer. He would see it rise bodies, resembling one another, and following one after another?" Were he to confine his attention to the occur
in the east, soar aloft, and then sink in the west. After
the lapse of a few hours it would again appear in the east, rences of only a few days, he would, perhaps, think the latter supposition to be correct, viz., that they were different
attain a height from which bodies which thus appeared to him day after day. But if
... With a boundless tide
Of silver radiance, trembling round the world, he were to continue his observations for weeks, months, years, or the greater part of his life, and to find that the
it would again descend, to sink as before in the west. The daily appearance of such a body still continued, he could
train of reasoning which would lead the observer to conclude hardly fail to conclude that it was the same body which thus that the sun revolved round the earth, would lead him to a so frequently attracted his attention and admiration. But similar conclusion regarding the moon. But here the re how ?" (he might say,) “ do I not see this ruddy disc of semblance terminates. The sun always presents a perfect light dip into the ground in the west, and appear to me circle to the eye of the observer day after day, and month again in the east on the following morning: what becomes after month; but a few evenings suffice to show that such of it in the meanwhile ?" To answer this question, or to is not the case with the moon : at one time a crescent only obtain the means of answering it, he would, perhaps, trace is seen, whose hollow side is towards the left of the observer; more particularly the path which the sun followed from at another time the hollow side is towards the right: the morning to evening, which he would find to be a semicircle, crescent sometimes enlarges to a perfect circle; and at or a curve not differing much from it. If, likewise, he others it contracts from a circle to a crescent. If, then, the were to take note of the time occupied in these occurrences, moon be a ball or globular body, shedding light upon
the he would soon find the time that the sun is above the surface earth, there is great difficulty in conceiving what can occaof the earth to be, on an average, equal to the time that itsion the change in its apparent shape; but, if we were to is invisible.
consider the moon to be an opaque or non-luminous body, From these two facts, it would be by no means unreason- we should find the means of explaining the change in its able to arrive at the conclusion, that the sun moves in a apparent figure, by supposing that the sun shines upon the circle; and that, while he is invisible to us, he is passing moon, and that it is only by the reflection of the sun's light round the earth, in a direction from west to east, at which from the moon that the moon becomes visible to us. If we latter point he arrives at the moment that the observer sees place a large round ball on a table, in a place where the sun him rise in the morning.
is shining, we shall see the ball more or less illuminated, Here a difficulty arises, which it may well be supposed, according to our position with regard to the ball and the would perplex the uninitiated observer.
What can be
sun: in one position, the ball will appear to be equally meant by going round the earth, if the earth be, as it seems to our eyes, a flat and extended surface of ground, or water, minated and the other in the shade : in another position,
divided by a boundary line, into two semicircles, one illuwhich seems to touch the sky at the farthest points which the illuminated portion will be only a crescent, all the rest the eye can reach:-how then can the sun pass round being shaded: from another point again it will all appear this ?' There can scurcely be a more reasonable question, illuminated, except a small crescent of shade. If the obso long as we judge merely by what meets the eye; but, server watch the relative positions of the sun and moon, if we extend our observations to certain appearances on the he will see that the shape of the bright part of the moon ocean, we begin to see proof that the surface of the water depends on its relative position in respect of the sun; just is not quite Hat. On land, we have not the means of as the bright portion of the illuminated ball depended on making a similar observation, because of the intervention the position in which he viewed it. of mountains and valleys. The proof that the surface of We should in this way find the means of accounting for water is not quite flat
, is derived from the following circum- | the change in the shape of the moon. We shall, by and bye, approach of a vessel from a distance, we find that the masts | point would attract the notice of the observer, independently are visible sooner than the hull: we'first see the top of the of the change in apparent form. If the two brilliant bodies, masts: then the whole height of the masts gradually comes the sun and moon, were observed to be near each other on a into view; and finally, we see the hull. These different certain day when ihe latter appeared as a thin crescent, to observer, are represented in the following figure. This removed, and on the following day, at a still greater distance could not occur if the
earth were perfectly flat, because then from each other: if, therefore, the motion of the moon the hull and masts would come into view at the same time. round the earth be admitted, 'it is necessary to suppose
that motion to be slower than the sun's motion round the earth.
But in addition to the glowing light of the sun and moon, a glittering assemblage of smaller bodies meets the eye of the observer: a crowd of little spangles adorns the sky when the sun has left it, and softens the dreary darkness which results from his absence. These stars are seen to resemble the sun and moon in the circumstance of rising in or near the east, attaining a certain altitude, and setting in the west; from which circumstance the observer infers
that the stars, like the sun and moon, revolve round the of the observer, and do not return till after a long absence. earth. But, by a careful attention to different stars, he | To such bodies we give the name of Comets. would find that the same remark does not apply to all. Such then are the equally sublime and facinating ap Those which rise exactly in the east, set exactly in the pearances which present themselves to the eye of an west; those which rise to the south of east, set south of observer, when that eye is directed towards the heavens. west; and many which rise somewhat north of east, set That the invigorating and fructifying warmth and light somewhat north of west; but in looking northward he sees shed by the sun,-the serene, quiet light of the moon,stars which appear neither to rise nor to set, but which and the diamond-like glittering of the stars,-should invite perform a complete circle round a particular point of the men to a study of the laws which, under their Divine hearens. For example,—there are seven stars, which, to Creator, govern the motions of such exquisite globes of most persons who pay any attention to the appearance of light, is what we are not only prepared to expect, but fancy the heavens, are known under the name of the Great Bear. that we should feel disappointment in finding it otherwise. These stars never rise or set to an inhabitant of London. Man is not, by nature, the cold heartless being who can let If they become invisible, it is either because clouds obscure such beauties pass unheeded; and if he approach the study them, or the superior brilliancy of the sun drowns their with the humility which true self-knowledge is calculated comparatively feeble light. The same may be said of five to engender, he becomes more and more able to appreciate conspicuous stars known by the name of Cassiopeia's the surpassing grandeur and power of the great Being who Chair.
made and who rules all. Well, indeed, may we direct our If we watch the progress of these stars, and others in attention to the phenomena which we have briefly detheir vicinity, we shall find that they describe a circle round scribed, and to which Milton so exquisitely alludes in the a star called the Pole-star. The position of this star we following lines :shall find to be nearly this: if we suppose the distance from
First in his East the glorious lamp was seen, the north point of our horizon (which is the line in which
Regent of day, and all th' horizon round the surface of the earth appears to touch the sky) to the
Invested with bright rays, jocund to run zenith (which is the point immediately over our heads) to
His longitude through Heaven's high road; the gray
Dawn, and the Pleiades * before him danced, be divided into five equal parts, then at about the height of
Shedding sweet influence: less bright the moon, three of those parts from the earth, will be seen the Pole
But opposite in levelld West was set star.
Ilis mirror, with full face borrowing her light All this would seem to show to an observer, that the
From him ; for other light she needed none Pole-star is the end of an axis round which all the stars
In that aspect, and still that distance keeps
Till night; then in the East her turn she sbines, revolve, and that the reason why we cannot see the whole
Revolved on Heaven's great axle, and her reign circular path of any stars except of those in the vicinity of
With thousand lesser lights dividual holus, the Pole-star, is, that they pass round under the earth
With thousand thousand stars, that then appear'd during a part of their journey, and are therefore concealed
Spangling the hemisphere : then first adorn'd from our view. Those stars which are further removed
With their bright luminaries that set and rose,
Glad evening and glad morn crown'd the fourth day. from the Pole-star describe a larger circle than those which
Par. Lost, b. vii. are nearer, while the Pole-star is almost stationary. This is exactly what takes place when we see a wheel turn round; the axle remains in one spot, but any particular THEORIES TO EXPLAIN THE MOTIONS OF THE HEAVENLY point on the outer edge of the wheel describes a larger cirele than that which is described by any point between the axle and the circumference.
IN very early ages, before Europe occupied a page in the If we consider the Pole-star to form one end of the axle history of nations, the phenomena of the heavens were or axis round which the stars revolve, then it is obvious studied with great attention by several nations of the that there must be an opposite end of the same axis, in East. The Chaldeans, the Indians, the Chinese, and the the contrary direction. If then we turn towards the south, Egyptians, have all left evidences of the industry and with the expectation of seeing such a point, we shall find ingenuity with which their observations were conducted. that it will not be realized; for none of the stars in that They constructed observatories,-invented instruments for quarter are seen to describe circles ; for they all rise and observing and measuring with accuracy,-separated the set. Still, however, the semicircles or portions of semi- stars into different groups, called Constellations, for the circles, commonly called arcs, which they describe, appear facility of finding any particular star,--gave particular to have a common centre, which is some distance below the names to most of the moving stars or planets, and noted horizon; and this centre may be considered as the southern the period which each took to move through its apparent end of the axis before spoken of.
path in the heavens; and, in many other ways, the ancients If we suppose the observer to have arrived at this amount helped to lay the foundation of that mass of astronomical of information respecting the stars, he will be prepared to knowledge which the men of later ages have brought to notice the uniformity of the positions of the stars with more maturity. respect to one another. The Great Bear, for instance, Various opinions were formed respecting the motions of whether it be under or over the Pole-star, or at the right or the sun, moon, and stars of all kinds, both with reference the left of it, will always have its seven principal stars at
to one another, and also to the earth; but the first theory the same relative distances from each other. The changes which had attained a name and an importance in the early which take place in the distance of the sun from the moon,
ages of the world, was that of Ptolemy, a distinguished would lead to the opinion that these revolve round the earth | Egyptian astronomer, who lived about one hundred and in unequal times; and by similar reasoning, the constant thirty years after the birth of Christ. He conceived that maintenance of the same distance between any two stars, the various bodies which had been distinguished by the would seem to imply that the stars revolve in equal times. appellation of “the heavenly host," were disposed in the
The seeming myriads of stars which present themselves order represented in the annexed diagram. to the notice of the observer all appear to follow this rule, He supposed, according to the popular opinion, that the of remaining at the same relative distances from one
Earth was fixed as the centre of the universe, and that the another, with very few exceptions. These exceptions, are, Sun, Moon, Planets, and Stars, revolved round it in the indeed, so few, that a constant watching of the same
following order; namely—the Moon, Mercury, Venus, Sun, part of the heavens for a considerable period, would be Mars, Jupiter, and Saturn; the Moon being the nearest, necessary to determine that a star had actually changed and so on ; exterior to all of which, he supposed that a its place relatively to other stars. There have, however, great concave sphere in which all the stars were fixed, kept been discovered at different times ten stars, more or less on revolving round the earth. From the early history of brilliant, which change their relative distances from one Astronomy, we learn that before the time of Ptolemy, it another, and from other stars. These we know by the name
had been conjectured by some, that the earth passed round of Planets; and by a careful attention to their movements, the sun, and not the sun round the earth; but the difficulty it is seen that each one travels in a curved path among the
of believing a statement so contrary to appearances and to other stars, and returns again nearly to the point from the evidence of one's physical senses, led to the rejection whence it set out.
of this opinion; and although it was afterwards found to be At intervals, again, star-like bodies of another order present themselves, whose progress among the other stars
* Seven small stars clustered together in the constellation Taurus.
These stars rise with the sun about the time of Spring, and our poet, is more rapid than that of the planets; and which at a
in this passage, intimates the old and common opinion that the period more or less brief, vanish altogether from the view Creation took place in the Spring.