no more than the forty thousandth part of the terraqueous* globe; so that, before we can acquire an adequate conception of the magnitude of our own world, we must conceive 40,000 landscapes, of a similar extent, to pass in review before us; and, were a scene, of the magnitude now stated, to pass before us every hour, till all the diversified scenery of the earth were brought under our view, and were 12 hours a day allotted for the observation, it would require 9 years and 48 days before the whole surface of the globe could be contemplated, even in this general and rapid manner. 4. But such a variety of successive landscapes passing before the eye, even although it were possible to be realized, would convey only a very vague and imperfect conception of the scenery of our world; for objects at the distance of 40 miles cannot be distinctly perceived; the only view which would be satisfactory, would be that which is comprehended within the range of 3 or 4 miles from the spectator. 5. Again, I have already stated, that the surface of the earth contains nearly 200,000,000 of square miles. Now, were a person to set out on a minute survey of the terraqueous globe, and to travel till he passed along every square mile on its surface, and to continue his route without intermission, at the rate of 30 miles every day, it would require 18,264 years before he could finish his tour, and complete the survey of" this huge rotundity on which we tread;" so that, had he commenced his excursion on the day in which Adam was created, and continued it to the present hour, he would not have accomplished one third part of this vast tour. Questions.-What is a globe? What is the meaning of diameter ? of circumference? terraqueous? What is the extent of the earth's surface, par. 5? What is a square mile? LESSON CXX. Number and Magnitude of the Stars. 1. If we extend our views from the solar system to the starry heavens, we have to penetrate, in our imagination, a space which the swiftest ball that was ever projected, though *Terraqueous, from two Latin words, meaning land and water. Terraqueous globe, a land and water globe,-the globe on which we live. in perpetual motion, would not traverse in ten hundred thousand years. In those trackless regions of immensity, we behold an assemblage of resplendent globes, similar to the sun in size, and in glory, and, doubtless, accompanied with a retinue of worlds, revolving, like our own, around their attractive influence. The immense distance at which the nearest stars are known to be placed, proves that they are bodies of a prodigious size, not inferior to our own sun, and that they shine, not by reflected rays, but by their own native light. 2. But bodies encircled with such refulgent splendor, would be of little use in the economy of Jehovah's empire, unless surrounding worlds were cheered by their benign influence, and enlightened by their beams. Every star is, therefore, with good reason, concluded to be a sun, no less spacious than ours, surrounded by a host of planetary globes, which revolve around it as a centre, and derive from it light, and heat, and comfort. 3. Nearly a thousand of these luminaries may be seen in a clear winter night, by the naked eye; so that a mass of matter equal to a thousand solar systems, or to thirteen hundred and twenty millions of globes of the size of the earth, may be perceived, by every common observer, in the canopy of heaven.. But all the celestial orbs which are perceived by the unassisted sight, do not form the eighty thousandth part of those which may be descried by the help of optical in struments. 4. The telescope has enabled us to descry, in certain spaces of the heavens, thousands of stars, where the naked eye could scarcely discern twenty. The late celebrated astronomer, Dr. Herschel, has informed us, that, in the most crowded parts of the Milky-way, when exploring that region with his best glasses, he has had fields of view which contained no less than 588 stars, and these were continued for many minutes; so that "in one quarter of an hour's time there passed no less than one hundred and sixteen thousand stars through the field of view of his telescope." 5. It has been computed, that nearly one hundred millions of stars might be perceived by the most perfect instruments, were all the regions of the sky thoroughly explored. And yet all this vast assemblage of suns and worlds, when compared with what lies beyond the utmost boundaries of human vision, in the immeasurable spaces of creation, may be no more than as the smallest particle of vapor to the immense ocean. Immeasurable regions of space lie beyond the utmost limits of mortal view, into which even imagination itself can scarcely penetrate, and which are, doubtless, replenished with the operations of Divine Wisdom and Omnipotence. 6. For it cannot be supposed that a being so diminutive as man, whose stature scarcely exceeds six feet-who vanishes from the sight at the distance of a league-whose whole habitation is invisible from the nearest star-whose powers of vision are so imperfect, and whose mental faculties are so limited-it cannot be supposed that man, who "dwells in tabernacles of clay, who is crushed before the moth," and chained down, by the force of gravitation, to the surface of a small planet,—should be able to descry the utmost boundaries of the empire of Him who fills immensity, and dwells in "light unapproachable." 7. That portion of his dominions, however, which lies within the range of our view, presents such a scene of magnificence and grandeur, as must fill the mind of every reflecting person with astonishment and reverence, and constrain him to exclaim, "Great is our Lord, and of great power; his understanding is infinite." "When I consider thy heavens, the work of thy fingers, the moon and the stars which thou hast ordained,-what is man, that thou art mindful of him!" Questions. What are each of the fixed stars supposed to be? How many may be seen by the naked eye? How many, is it supposed, might be seen by the most perfect instruments? What is the name of the instrument used to assist the eye in looking at distant objects? LESSON CXXI. Rapid Motions of the Celestial Bodies. 1. THE rapid motions of the great bodies of the universe, no less than their magnitudes, display the Infinite Power of the Creator. We can acquire accurate ideas of the relative velocities of moving bodies, only by comparing the motions, with which we are familiar, with one another, and with those which lie beyond the general range of our minute inspection. 2. We can acquire a pretty accurate conception of the velocity of a ship impelled by the wind-of a steam-boatof a race-horse-of a bird darting through the air—of an arrow flying from a bow—and of the clouds, when impelled by a stormy wind. The velocity of a ship is from 8 to 12. miles an hour,—of a race-horse, from 20 to 30 miles—of a bird, say from 50 to 60 miles, and of the clouds, in a violent hurricane, from 80 to 100 miles an hour. 3. The motion of a ball from a loaded cannon is incomparably swifter than any of the motions now stated; but of the velocity of such a body, we have a less accurate idea; because, its rapidity being so great, we cannot trace it distinctly by the eye, through its whole range, from the mouth of the cannon to the object against which it is impelled. By experiments, it has been found, that its rate of motion is from 480 to 800 miles in an hour; but it is retarded every moment by the resistance of the air and the attraction of the earth. 4. This velocity, however, great as it is, bears no sensible proportion to the rate of motion which is found among the celestial orbs. That such enormous masses of matter should move at all, is wonderful; but when we consider the amazing velocity with which they are impelled, we are lost in astonishment. The planet Jupiter, in describing his circuit round the sun, moves at the rate of 29,000 miles an hour. 5. The planet Veņus, one of the nearest and most brilliant of the celestial bodies, and about the same size as the earth, is found to move through the spaces of the firmament at the rate of 76,000 miles an hour; and the planet Mercury, with a velocity of no less than 150,000 miles an hour, or 1750 miles in a minute-a motion two hundred times swifter than that of a cannon ball. These velocities will appear still more astonishing, if we consider the magnitude of the bodies which are thus impelled, and the immense forces which are requisite to carry them along in their courses. 6. However rapidly a ball flies from the mouth of a cannon, it is the flight of a body only a few inches in diameter; but one of the bodies, whose motion has been just now stated, is eighty-nine thousand miles in diameter, and would comprehend, within its vast circumference, more than a thousand globes as large as the earth. Could we contemplate such motions, from a fixed point, at the distance of only a few hundreds of miles from the bodies thus impelled, it would raise our admiration to the highest pitch; it would overwhelm all our faculties, and, in our present state, would produce an impression of awe, and even of terror, beyond the power of language to express. Questions-What is the meaning of velocity? What is the velocity of a ship, per hour? of a race-horse? of a bird? of a cannon ball? of the planet Jupiter? Venus? Mercury? LESSON CXXII. Popular Illustration of the Motions of the Earth and Heavens. 1. PERSONS of common understanding may be made to comprehend the leading ideas of extended space, magnitude, and motion, which have been stated above, provided the description be sufficiently simple, clear, and well defined; and should they be at a loss to comprehend the principles on which the conclusions rest, or the mode by which the magnificence of the works of God has been ascertained, an occasional reference to such topics would incite them to inquiry and investigation, and to the exercise of their powers of observation and reasoning on such subjects-which are too frequently directed to far less important objects. 2. The following illustration, however, stands clear of every objection of this kind, and is level to the comprehension of every man of common sense.-Either the earth moves round its axis once in twenty-four hours-or the sun, moon, planets, comets, stars, and the whole frame of the universe, move round the earth, in the same time. There is no alternative, or third opinion, that can be formed on this point. 3. If the earth revolve on its axis every twenty-four hours, to produce the alternate succession of day and night, the portions of its surface about the equator must move at the rate of more than a thousand miles an hour, since the earth is more than twenty-four thousand miles in circumference. This view of the fact, when attentively considered, furnishes a most sublime and astonishing idea. 4. That a globe of so vast dimensions, with all its load of mountains, continents, and oceans, comprising within its circumference a mass of two hundred and sixty-four thou |