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and planet being only as the pores in a grain of sand, and the spaces between system and system no more than the intervals between one grain and the grain adjacent."1

NICHOL.

DISCOVERY OF PARALLAX AMONG THE FIXED STARS.

This is the greatest and most glorious triumph 2 that practical astronomy has ever witnessed. Perhaps I ought not to speak so strongly-perhaps I should hold some reserve in favour of the bare possibility that it may be all an illusion— and that farther researches, as they have repeatedly before, so may now, fail to substantiate this noble result. But I confess myself unequal to such prudence under such excitement. Let us rather accept the joyful omens of the time, and trust that, as the barrier has begun to yield, it will speedily be effectually prostrated. Such truths are among the fairest flowers of civilisation; they justify the vast expenditure of time and talent which have led up to them; they justify the language which men of science hold, or ought to hold, when they appeal to the governments of their respective countries for the liberal direction of the national means in furtherance of the great objects they propose to accomplish. They enable them not only to hold out, but to redeem their promises, when they profess themselves productive labourers in a higher and richer field than that of mere material and physical advantages. It is, then, when they become (if I may venture on such a figure without irreverence) the messengers from heaven to earth of such stupendous announcements as must strike every one who hears them with almost awful admiration, that they may claim to be listened to;—when they repeat, in every variety of ur

1 This is merely an expansion of the thought of Newton, that there is no contact in the particles of matter, that the densest body is porous, and that the interspaces of such a body may contain inicroscopic organic worlds.

2 Parallax, see note 1, p. 21:-Triumph; this is said in reference to the results of the observations of Struve, the superintendent of the Russian Imperial Observatory at Dorpat in Livonia; of the German astronomer Bessel; of Professor Henderson of Edinburgh, &c. The discovery of the parallax furnishes the data for ascertaining the distances of the stars; thus Bessel demonstrates the double star 61 Cygni, (see note 2, p. 20,) with a parallax of one-third of a second, to be 667,780 times the distance of our Sun; and Struve shows that a Lyræ, with a parallactic angle of one-fourth of a second, is 876,000 times farther from us than the Sun. The difficulty of observing the parallactic angles of the stars arises from the fact, that their distance is such that the diameter of the Earth's orbit, whose extremities are the points of observation, forms in comparison with it an inappreciable quantity.

In reference to the munificence of the Czar's patronage of science.

gent instance, that these are not the last of such announcements which they shall have to communicate; that there are yet behind, to search out and to declare, not only secrets of nature which shall increase the wealth or power of man, but truths which shall ennoble the age and country in which they are divulged, and, by dilating the intellect, react on the moral character of mankind. Such truths are things quite as worthy of struggles and sacrifices as many of the objects for which nations contend and exhaust their physical and moral energies and resources. They are gems of real and durable glory in the diadems of princes; and conquests which, while they leave no tears behind them, continue for ever inalienable.-SIR JOHN HERSCHEL.1

VELOCITY OF THE TRANSLATORY MOTION OF STELLAR ORBS IN SPACE.

Let us turn our thoughts onward, and ask what is the nature and velocity of this grand solar motion? Singular though it may seem, it appears probable that we can now approach the solution even of this most remote and difficult question, and this by means of one of those stars whose distances we have discerned from our sphere. It is Bessel's 61 Cygni. The circumstances are briefly these:-The remoteness of this star from our planetary sphere is definitely about 670,000 times our distance from the Sun; and we have accurately determined its apparent motion through space. Its distance from the point of observation being known, that apparent angular motion can be converted into an apparent motion of so many miles; just as a traveller could tell, should a remote object appear to be in motion-if he knew the interval dividing him from it-the exact amount of its displacement. Now, if this displacement of 61 Cygni is owing, as it is in all likelihood, not to its proper motion, but to the translation of the Sun, we may clearly infer, on the simple principle above stated, with what velocity we are darting through space. In Bessel's opinion, we may move in this immense orbit thrice as fast as the Earth travels in its planetary ellipse, or with a speed so swift that we might reach 61 Cygni in 41,000 years. Now, large though this period is, there is nothing in it whatever to overwhelm our imagina

1 This extract is taken from Nichol's Stellar Universe.

tion. If geology is not the veriest fable, if we are not to return to the old conceptions, that the rocks of our world's crust, with their entombed creatures, have been laid down there purposely as the most mocking of enigmas1-an enigma that seems to have a meaning and yet has none even this great course of years is only a very brief point amid the latest changes affecting the surface of the Earth. Free then from fear, let us rise far higher; and assuming that Bessel's star indicates the average distance of the nearest orbs, we infer that the Sun would require no more than 500,000 years to reach that extremest verge at which the eye can descry a single star; nay, it could reach that remotest distance to which Lord Rosse's telescope can pierce, in about two hundred and fifty millions of years; and so far is even this stupendous period from sounding all the working time of Nature, that many of the mountains of our earth may, through its whole duration, have been in being, rearing their peaks towards different constellations, and surviving, in their littleness and fragility, even these immense transitions! The numbers I have quoted are indeed only approximate, but, in rendering conceivable a subject so vast and vague, they have, notwithstanding their necessary inaccuracy, an importUnder their direct announcements, the stability of our supposed universe wholly disappears. The stars that shine over us now may indeed be those that arrested the ardent gaze of the Chaldeans; but at depths of time by no means beyond our reach, we must have passed through many arrangements of orbs; and if, as assuredly they do, these stars move like the Sun, our majestic cluster may not now, in any part, have even a similitude of what it was! How stupendous such ceaseless evolutions! How overwhelming the thought, that what above all things seemed the fitting emblem of the Eternal, is thus almost visibly subject to transiency; even in its most august and awful forms, only one phase of the fleeting and phantasmal.

ant use.

NICHOL.

COLOURS OF DOUBLE STARS.

It has long been observed that the stars shine with different colours; for the diversity is visible to the naked eye. Among

1 See Granville Penn's Mineral and Mosaical Geologies.

those of the first magnitude, for instance, Sirius, Vega, Altair, Spica, are white; Aldebaran, Arcturus, Betelgueux, red; Capella and Procyon,1 yellow. In lesser stars the difference is not so perceptible to the eye, but the telescope exhibits it with equal distinctness. It is likewise far more striking in countries where the atmosphere is less humid and hazy than ours. In Syria, for instance, one star shines like an emerald, another like a ruby, and the whole heavens sparkle as with various gems. Now, this attribute of variety of colour distinguishes also the double stars,2 which, indeed, was to be expected; but the association of these colours presents a new and remarkable phenomenon. Struve records, that in at least 104 binary systems the two stars exhibit the complementary colours, that is, the colour of one constituent belongs to the red, or least refrangible end of the spectrum, while that of the other belongs to the violet, or most refrangible extremity, as if the entire spectrum3 had been divided into two parts, and distributed between the two companions. It has been supposed that this phenomenon is the mere effect of contrast, or of an optical delusion, depending on the well-known law, that when the eye has looked for a time on one bright light, it is inclined to clothe any smaller light near it with the opposite or complementary colour for the sake of relief. The explanation is plausible, but it will not stand testing.4 What novelties—what peculiarities, the existence of double and parti-coloured suns must cause to the planets encircling them!"It may be easier suggested in words," says Sir John Herschel," than conceived in imagination, what a variety of

* * *

1 Sirius, the dog-star, the brightest star in the sky, in the constellation Canis Major; Vega, in Lyra; Altair, in Aquila and Antinous; Spica, (the corn-ear,) in Virgo; Aidebaran, (the bull's eye,) in Taurus; Arcturus, (the bear-ward,) in Bootes; Betelgueux, in Orion's shoulder; Capella, (the goat,) in Auriga, (the charioteer); Procyon, (the front dog,) in Canis Minor.

2 The power of modern telescopes has discovered that many stars, which appear as single to the eye or to smaller instruments, are combinations of two or more orbs, that move in relation to each other, in systems binary, ternary, &c. It was believed that this apparent proximity was accidental, arising from the manner in which the bodies were presented to the eye; but extensive observations have established the fact, that these combinations are really systems of suns, probably sustaining around their central forces thousands of illuminated planetary worlds. Among other wonders of the Stellar Astronomy are periodically variable stars; temporary stars; and mythology, in such a tale as the lost Pleiad, may indicate the fact of the disappearance in early ages from the sky of bodies familiarly observed.

3 Spectrum, the seven lines of colour into which a ray of light is divided by transmission through a prism; the positions of the colours on the spectrum arise from the different degrees of refrangibility or bending from the straight line, that exists in the rays which compose a beam of white light: the order of the colours is red, orange, yellow, green, blue, indigo, and violet.

* Because the colours are not always complementary, but frequently belong both to one end of the spectrum; and because, if the one star be hid from the eye, and the optical contrast be thus removed, the complementary star still retains its proper colour.

illumination two stars-a red and a green, or a yellow and a blue one-must afford to a planet circulating round either; and what cheering contrasts and grateful vicissitudes a red and a green day alternating with a white one and with darkness must arise from the presence or absence of one or other or both from the horizon!" All the products of the material constitution of this earth, the character of its living families, perhaps the action of its magnetic and other influences, are co-ordinated and adjusted to the regular succession of night and day, or to the supply and nature of our Solar light. No such families, then, none bearing other than remote analogies to ours can exist in planets engirdling such double And who, after all, would grieve although there be some inclosed spots-quietudes in creation, which will be unexplored, unpenetrated for ever; who that has felt the soft healing of evening, can regret that, even in the intellectual world, there are regions into which faintness and weariness may sometimes flee, and take shelter and repose, away from the scorch and glare of oppressive light! Sweet and inviting mysteries-among whose gentle shadows Hope and Fear, and all unnamed yearnings, tremblingly advance, and find or fashion for themselves images of purity, convictions of immortality, vistas of a life to come, through which the soul may wander freer and quieter than now, "having gained the privilege by Virtue."-NICHOL.

suns.

THE MICROSCOPIC WORLD.

About the time of the invention of the telescope another instrument was formed, which laid open a scene no less wonderful, and rewarded the inquisitive spirit of man with a discovery no less important. This was the microscope. The one led me to see a system in every star; the other leads me to see a world in every atom. The one taught me that this mighty globe, with the whole burden of its people and of its countries, is but a grain of sand on the high field of immensity; the other teaches me that every grain of sand may harbour within it the tribes and families of a busy population. The one told me of the insignificance of the world I tread upon; the other redeems it from all its insignificance, for it tells me that in the leaves of every forest, and in the flowers of every garden, and in the waters of every rivulet,

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