London on the 20th of March 1727, having long enjoyed the honours due to his exalted genius, and been furnished with the means of acquiring considerable wealth. All through life he recognised the primary importance of religion, especially the claims of revealed religion, and the paramount authority of the word of God. Towards the close of his days, when an invalid, he read much; and the book which was commonly lying before him, and to which he most frequently turned at last, was a duodecimo Bible. His death was deplored as a national loss; and his obsequies were celebrated with peculiar distinction. The body, after lying in state in the Jerusalem Chamber, was interred in Westminster Abbey, six peers bearing the pall. A Latin inscription on the monument that marks the grave closes with the sentence mortals congratulate themselves that so great an ornament of the human race has existed." The Royal Society of London possesses his telescope; the Royal Society of Edinburgh the door of his book-case; and Trinity College, Cambridge, has a lock of his silver white hair.

"Let

While Newton completely established the existence of the principle of gravitation, succeeding physical astronomers have more fully developed its consequences, and unfolded its empire, successfully applying it to phenomena beyond the bounds of our system, as to the binary and multiple schemes of stars, which the powerful telescopes of modern date have discovered. They have also demonstrated, that under its rule, stability and permanence are consistent with constant perturbation and incessant change. As each of the worlds around us exerts an influence upon all the others, planet swaying planet, and satellite bending to

satellite their orbits are not invariable, but slowly rock to and fro, contracting and expanding, as the effect of their mutual attraction. Hence, at first sight, nothing seems more probable, than that such disturbances may lead eventually, by accumulation, to the destruction of the system. But it has been placed beyond a doubt, that every irregularity in the motion of the planets, and in the form of their orbits, is periodical; in other words, the inequality has its assigned limits, beyond which it can never pass: so that, after reaching its maximum, it will diminish according to the same law by which it increased. Ever since the date of the earliest astronomical observations, the orbit of the earth has been slowly losing its eccentricity, and changing from an ellipse into a circle, thereby accelerating the mean motion of the moon. But after a certain cycle, this change, by virtue of the same cause that produces it, will be corrected, and the orbit gradually return to its former ellipticity, the moon's motion being proportionally retarded. In a similar manner, all the planets experience perturbations, which oscillate through long cycles of time within definite limits, having a bound set to them by a "perpetual decree." There is thus no chance-work or faulty architecture in the construction of our mighty system; neither has it been arranged upon the principle of self-destruction. It is not wearing itself out. The great Machinist is ever with the work of his own hands, observing and directing every motion; and whenever an end shall come to the present constitution of things, it will not be the result of nature's decay or disorder, but of the fiat of the Almighty.

CHAPTER III.

THE GREATER LIGHT.

Distance of the Sun-Mean Distance-Solar Diameter - CircumferenceVolumes and Masses of the Sun and the Earth-Results-Solar Rotation -Spots observed by the Naked Eye-Early Telescopic Observations Appearances caused by the Solar Rotation - Rapid changes of the SpotsTheir Magnitude-Nucleus and Penumbra - Bright Spots - Theory of Wilson-Views of Herschel-Observations of the Solar Spectrum-Fraunhofer's lines-Spectrum of the Solar Prominences-The ChromosphereAnalysis of the Sunbeam--Importance of the Luminous Principle-Influence on Vegetation - The Solar Heat-Chemical Rays Zodiacal Light-Blessings of the Light.

THE Sun, "the light that rules the day," is a selfradiant spheroid of matchless splendour, the mighty ruler, and animating principle of a group of circumvolving worlds, seated at the centre; for the farthest member of the planetary system is, equally with the nearest, directed in its movements, and maintained in its orbit, by the force of the solar attraction. The grand luminary has dimensions in accordance with this supremacy of aspect, position, and office; but appears only as a small circlet in the firmament, owing to the vastness of its distance from the terrestrial spectator. By careful computations, chiefly based upon observations of the transits of Venus, it has been found that the sun's mean distance from the earth is, in round numbers, ninetytwo millions of miles; and this conclusion is supposed to involve no inaccuracy greater than oth part of the whole. Though light travels across the mighty gulf in eight minutes, yet with any velocity which we can create, it would require a long interval of time to make the passage. A cannon ball, retaining through

out its full force, would be about seven years in effecting it; and a railway train, moving incessantly thirty miles an hour, would be three centuries and a half on the route. To the uninstructed, it appears marvellous in the extreme, and scarcely credible, that the distances of the heavenly bodies, with their magnitudes and velocities, can be calculated with any degree of exactness. But those who cannot fully understand the way in which such problems are solved, may be convinced of their accuracy and truth, by remembering the precision with which eclipses, occultations, and transits are predicted. The remark may be added, that nothing is more common in surveying countries, and conducting siege operations, than for the distance of terrestrial objects to be determined, without traversing the intervening ground; and the measurement of distances in the heavens depends on the same infallible geometry.

The mean distance of the sun supposes a greater and a less. There would be no variation if the earth described a perfect circle in the course of its annual revolution. But moving in an elliptical orbit, it is nearer the sun at one point by about three millions of miles than at another. An interval of six months elapses between the two extremes; and the mean distance is a balance struck between them. This periodic variation of distance is manifested by a slight difference in the apparent magnitude of the solar globe. When the earth is at its nearest point to the sun, the latter has an apparent diameter of 32′ 35′′-6, which is reduced to 31' 30", at an opposite season, when most remote. It may here be stated, that the sun's apparent diameter at any given time is the same, whether measured in the horizontal or vertical direction, except when near the horizon. Then the disk occasionally

exhihits an oval form, owing to the rays of light from the upper and lower limbs being unequally refracted in passing through the atmosphere. Intelligently have the foundations of the earth been laid, at such a distance from the source of light and heat, as is exactly suited to the organized forms upon its surface. If much nearer or more remote, animals and plants would perish, without some change of constitution, owing to increased heat or cold; and the blaze of light would be insufferable, or its amount too small to serve the purposes of vision.

It is obvious that a body must be of stupendous size to form such a conspicuous circle in the heavens as the sun, while at the distance of nearly a hundred millions of miles from us. The sun's diameter is not less than 856,500 miles, or rather more than one hundred and eight times the diameter of the earth. It is difficult to conceive aright of this enormous magnitude; but it may be illustrated by the statement that the solar globe would fill up the entire orbit of the moon, and stretch beyond it more than two hundred thousand miles in every direction. Were the sun a hollow sphere perforated by a thousand openings to admit the twinkling of the luminous atmosphere without, then a globe as large as our own might be placed at the centre, with a satellite as large as the moon, and at the same distance from it as she is from the earth, and there would be present to the eye of the spectator, on the interior globe, a universe as extensive as the whole creation was conceived to be in the infancy of astronomy, and as splendid as the heavens appear at present to the uninstructed gazer. Supposing the earth to be represented by a ball of one inch in diameter, another of nine feet four inches would represent the size of the sun. The loftiest of the earth's