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with reference to the moral government of the human race, which I have been endeavouring all along to establish? This is a chequered scene of brightness and gloom, of sunshine and shade, of enjoyment and depression; and such is the discipline best suited to our fallen condition.

In turning from our own satellite to those of the other planets, a similar train of reasoning may be applied. These nightly luminaries attached to Jupiter, Saturn, and Uranus, certainly compensate in some degree, by their numbers, for the increased deficiency of light arising from the remoteness of their primaries from the sun. This view will not be successfully redargued by the fact already stated, that Mars, and the four small planets still more distant than he from the source of light, are destitute of these useful appendages. The answer to such an objection just is, that, according to the analogy of creation, we may expect exceptions for which we may be altogether incapable of assigning an adequate cause; but the ignorance inherent in our limited views, can never invalidate the evidence of facts and principles clearly established.

FIFTH WEEK-TUESDAY.

VIII. THE STARRY HEAVENS.-RELATIVE PROPORTIONS OF THE

PLANETARY SYSTEM.

BEFORE Concluding our remarks on the system with which we are more immediately connected, it may be useful to take a general survey of the whole, in its relative proportions, that we may be enabled to form to ourselves some idea of the enormous scale on which even our comparatively diminutive department of the universe is constructed. It is exceedingly difficult for the mind to compare very great things with each other; because, beyond a certain point, all proportions seem to be lost in a kind of undefined immensity. We are commonly conversant with things on so minute a scale, being

ourselves mere atoms, as it were, of a little planet, that it requires an effort to raise our thoughts to so vast a subject; and, in contemplating it, we are, at every step, forced to feel the inadequacy of our own powers of comprehension. It is reported of some savages, that the scantiness and trifling nature of the objects which occupy their attention, have so contracted their faculty of estimating quantities, that they have no means of enumeration beyond the number of their fingers; and all groups of objects above ten are expressed in their language by a word which implies what is innumerable, on account of its immensity. We are surprised at the want of comprehension which this indicates; but it is, in reality, only a greater degree of a defect which belongs to the condition of our nature and circumstances as human beings; and the astronomer himself, familiar as he is with numbers and quantities, the very statement of which startles a less practised mind, comes quickly to a point, at which, though his mechanical power of calculation may continue, his imagination flags, his judgment is confounded, and he finds himself much in the state of the untutored savage.

The author from whom we yesterday made an interesting quotation adverting to this difficulty, has taken an ingenious method of bringing the relative proportions and distances of the bodies connected with our system, nearer to a level with a common apprehension, by reducing their dimensions. If we suppose the earth,' says he, 'to be represented by a globe, a foot in diameter, the distance of the sun from the earth will be about two miles; the diameter of the sun, on the same supposition, will be something above a hundred feet; and, consequently, his bulk such as might be made up of two hemispheres, each about the size of the dome of St. Paul's. The moon will be thirty feet from us, and her diameter three inches, about that of a cricket ball. Thus, the sun would much more than occupy all the space within the moon's orbit. On the same scale, Jupiter would be above ten miles from the sun, and Uranus forty. We see, then, how thinly scattered through space are the heavenly bodies. The fixe

stars would be at an unknown distance; but, probably, if all distances were thus diminished, no star would be nearer to such a one foot earth than the moon now is to us. On such a terrestrial globe, the highest mountains would be about one-eightieth of an inch high, and, consequently, only just distinguishable. We may imagine, therefore, how imperceptible would be the largest animals. The whole organized covering of such an earth would be quite undiscoverable by the eye, except perhaps by colour, like the bloom on a plum.*

*

'In order to restore the earth and its inhabitants to their true dimensions, we must magnify the length, breadth, and thickness, of every part of our supposed models, forty millions of times; and, to preserve the proportions, we must increase equally the distances of the sun and of the stars from us. They seem thus to pass off into infinity; yet each of them, thus removed, has its system of mechanical, and perhaps of organic, processes, going on upon its surface.'†

While, by the process of diminution, we are enabled to form a clearer estimate of the relations of those vast bodies which exist in our system, we may accomplish a similar object by magnifying those which, from their minuteness, strain our imagination on the other side. By far the greater part of organized beings are so small, that the human eye in its naked state, formed only for the discernments of objects of practical utility, cannot detect them. These the microscope

* Sir John Herschel's illustration of the relative magnitudes and orbits of the planets is not less striking:-'Choose any well levelled field or bowling-green: on it place a globe two feet diameter, this will represent the SUN; Mercury will be represented by a grain of mustard-seed, on the circumference of a circle 164 feet in diameter from its orbit; Venus, a pea, on a circle 284 feet in diameter; the Earth also a pea, on a circle of 430 feet; Mars, a rather large pin's head, on a circle of 654 feet; Juno, Ceres, Vesta, and Pallas, grains of sand, in orbits of from 1000 to 1200 feet; Jupiter, a moderate sized orange, on a circle nearly half a mile across; Saturn, a small orange on a circle of four-fifths of a mile; and Uranus, a full sized cherry or small plum, upon the circumference of a circle more than a mile and a half in diameter.'

+ Whewell's Bridgewater Treatise, pp. 273, 274.

discloses; and, while they thus become apparent to the sight, it requires a similar process of the mind to bring their amazing minuteness within the scope of the understanding. We know,' says our author, 'that we may magnify objects thousands of times, and still discover fresh complexities of structure. If we suppose, therefore, that we thus magnify every member of the universe, and every particle of matter of which it consists, we may imagine that we make perceptible to our senses the vast multitude of organized adaptations which lie hid on every side of us; and, in this manner, we approach toward an estimate of the extent through which we may trace the power and skill of the Creator, by scrutinizing his work with the utmost subtlety of our faculties.'

These views are calculated to impress the mind with very elevated and interesting conceptions of the stupendous nature of those Divine perfections, by which our system was originally called into existence, and is still upheld and governed; but it is, after all, but the entrance to a survey of the universe. The planetary system to which we belong, is but that of a single star; and, when we cast our eye over the heavens, and endeavour to rouse our faculties to the comprehension of the fact, that every one of those little twinkling lights with which the blue vault is bespangled, with the exception only of those few which are known to change their relative positions, is a sun like our own, and that each of them has, in all probability, a planetary system analogous to ours, we want words to express the sublimity of the conception, and receive a more vivid impression of the feelings of the poet of the Seasons, when overpowered by the vastness of his subject, he exclaims

'I lose

Myself in HIM-in light ineffable!

Come, then, expressive silence-muse His praise.'

FIFTH WEEK-WEDNESDAY.

IX. THE STARRY HEAVENS.-DISTANCE OF THE FIXED STARS.

THE precise distance of any of the fixed stars cannot be ascertained by such means as have hitherto been employed by astronomers, although it may be considered as certain, that the nearest of them does not approach our sun so near as nineteen trillions of miles! The calculation by which this inconceivable distance is established, is entirely satisfactory, and may readily be understood. I shall state it in as popular a manner as I can. As the earth moves round the sun at the average distance of about 95,000,000 of miles, it follows that she must be nearer those fixed stars that lie in the plane of her orbit, at one period of the year than at another, by double that distance, or 190,000,000 of miles; but it has been found that an approach of this immense amount makes not the very slightest perceptible alteration in the apparent size of these bodies; and hence we justly conclude, that 190,000,000 of miles is but as a point in comparison of the space which still intervenes between us and them. On this fact we may form a loose estimate of a distance within which the stars, situated as I have mentioned, cannot be stationed. But we must take another and somewhat more scientific method of judging with regard to the distance of those stars which are otherwise situated. It might be expected, that the vast diameter of the earth's orbit would produce some perceptible amount of annual parallax in the stars; that is to say, that in moving over this immense space, some change would be effected in their relative position, just as a lateral movement of a few miles along a road produces a change in the outline even of the most distant hills. Were this the case, the distance of the stars might be ascertained with some degree of accuracy. But it is not so: 'After exhausting every refinement,' says Sir John Herschel, 'astron omers have been unable to come to any positive or coincident

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