refer objects to a place in the straight line of the direction of the ray, at the moment it enters the eye. It follows, that sun, moon, and stars, are seen for a short time before they actually rise, and for a short time after they have set.

In giving the earth to the children of men, the Most High prepared it for their accommodation with wisdom, benignity, and power; for while the arrangements of terrestrial nature abound with instances of skilful and beneficent contrivance, their efficiency has been maintained unimpaired age after age. "For ever, O Lord, thy word is settled in heaven. Thy faithfulness is unto all generations: thou hast established the earth, and it abideth; they continue this day according to thine ordinances: for all are thy servants." Days, with the succession of light and darkness, the morning and evening twilight, have followed each other at definite intervals with precision, by the earth rolling upon its axis with uniform velocity; years, with the cycle of the same seasons, have revolved with unfailing regularity, because the course of our planet round the sun has been incessantly pursued, never shifting the direction of the axis of rotation; the atmosphere has faithfully performed its functions, the ocean has steadily kept its bounds, and the continents have everywhere nad their vegetation spontaneously renewed, while, as the reward of industry, giving seed to the sower, and bread to the eater. Familiarity with the phrases, diurnal rotation and annual revolution, is apt to weaken impressions respecting the movements they denote. But their magnificence, ease, and noiselessness amply deserve attention. It is a truly astonishing thought, that, "awake, asleep, at home, abroad," we are constantly carried round with the terrestrial mass, at the

rate of eleven miles a minute in our latitude, and are, at the same time, travelling with it in space with a velocity of sixty-six thousand miles an hour. Thus, during the twenty minutes consumed in walking a mile from our thresholds, we are silently conveyed more than twenty thousand miles from one portion of space to another; and during a night of eight hours' rest, or tossing to and fro, we are unconsciously translated through an extent equal to twice the distance of the lunar world. Viewed in connexion with parallel phenomena in the system, such examples of ponderous masses combining marvellous velocities with perfect order, will seal the truth upon the reflecting mind, "The Lord God omnipotent reigneth." "Blessed be

the Lord God, the God of Israel, who only doeth wondrous things. And blessed be his glorious name for ever: and let the whole earth be filled with his glory."

I

CHAPTER VI.

THE LESSER LIGHT.

Scheme of Satellites-Magnitude and Distance of the Moon-Variation of Distance-Proper Motion of the Moon-Sidereal and Synodic Revolution -Phases of the Moon-Lunar Crescent-Earth-light-Months and Weeks -New Moon of the Jews-Rotation upon an Axis-Its Peculiarity-No Atmospheric Indications-Dusky Patches on the Disk-Singular Explanation-Lunar Maps-Models-Supposed Lunar Seas-Evidence of Superficial Inequalities-Mountains of the Moon-Remarkable StructureRing-mountains and Bulwark-plains-Tycho-The Apennines-Eratosthenes-Mare Imbrium described-Supposed Lunar Effects-Influence on the Weather-Felling Timber-The Red Moon-Statements of Travellers-Explanation-Lunacy-The Tides-The Harvest Moon - General

Inference.

THOUGH One of the most inconsiderable bodies in the heavens as to magnitude, the moon is to mankind, next to the sun, the most engaging and useful, as the light that "rules the night," the main cause of the tides, while guiding the mariner across the ocean by the advantage which science has taken of her rapid changes of position with reference to the stars. In courtly and rustic life-in palaces and cottages-the lunar world has been regarded in all ages with respect and admiration, as an emblem of modest beauty and faithful attendance; and while her varying aspects have indicated to barbarous tribes weeks and months, times and seasons, astronomers have studied them with greater attention than any other celestial appearances, owing to her greater proximity bringing the orb within more convenient range of their telescopes. Some of the finest bursts of poetry have been inspired by the

placid loveliness of the queen of night, such as the description of the Greek bivouac in the Iliad, the merit of which, in the following version, is perhaps less due to Homer than to Pope :

"As when the moon, refulgent lamp of night,

O'er heaven's clear azure spreads her sacred light,
When not a breath disturbs the deep serene,
And not a cloud o'ercasts the solemn scene;
Around her throne the vivid planets roll,
And stars unnumber'd gild the glowing pole ;
O'er the dark trees a yellower verdure shed,
And tip with silver every mountain's head;
Then shine the vales, the rocks in prospect rise,
A flood of glory bursts from all the skies:
The conscious swains, rejoicing in the sight,

Eye the blue vault, and bless the useful light."

With this stedfast companion of the earth the scheme of satellites in the system commences; and, with the exception of Mars, it is a feature belonging to the great planets exterior to the earth. The want of a satellite, in the instance mentioned, may be provided for by the extent and density of the planet's atmosphere. These secondary bodies are not improbably designed to supply their primaries with reflected solar light when deprived of its direct beams, and to compensate for the diminished power of the "sun's directer ray," consequent on their vast distance. Hence, while the earth has only a single moon, Jupiter, at five times its distance from the luminary, has four; and Saturn, at nine times the distance, has eight, with an apparatus of rings, equal in illumination to many such attendants. The still more remote planets are similarly provided, and may have extensive trains which escape our notice, owing to the immensity of the intermediate space. Of the eighteen satellites at present recognized as belonging to the system, seventeer. would have remained for ever unknown but for the telescope. Of these nine have been discovered exclu

ively with the refracting, and seven exclusively with the reflecting telescope, while the remaining one was discovered by the independent, but simultaneous use of two instruments, a refractor and reflector. It is probably a law with all these secondary bodies, that they have an axial rotation, performed in exactly the same time as their revolution round their primaries. This is true of our own moon, and of the satellites of Jupiter; but it is one of those mechanical arrangements in the universe utterly inscrutable in its design.

The moon, though apparently as large as the sun, is the smallest of all the heavenly bodies obvious to the naked eye, having a diameter of only 2164 miles. Her surface is, consequently, thirteen times less than that of the earth; her bulk forty-nine times less; and it would require seventy millions of such bodies to be rolled together to equal the volume of the sun. But the mean distance of the moon from the earth being but 238,000 miles, or one four-hundredth part that of the sun, she rivals the great orb of day in apparent magnitude, and figures conspicuously in the nightly firmament. Moving round the earth in an elliptical orbit, the real distance of the satellite varies to the extent of 30,000 miles; and the apparent lunar diameter varies proportionably, from 33′ 31′′ when nearest to us, to 29' 21" when furthest off. This variation of distance and apparent diameter is made manifest by eclipses. Sometimes, as when nearest the earth, the lunar disk is larger than the solar, and a total eclipse of the sun is caused by its interposition. At other times, when most distant, the lunar disk is smaller than the solar, and under similar circumstances, a portion of the sun is seen encircling the dark orb of the moon, producing a ring-like, or annular eclipse.