We do not know that any new and higher forces have been added to matter since man's acquaintance with it. But it would be easy to add any number of them, or change any lower into higher. That is the meaning of the falling granite that becomes soil, of the pulverized lava that decks the volcano's trembling sides with flowers; that is the meaning of the grass becoming flesh, and of all high forces constitutionally arranged for mastery over lower. Take the ore from the mountain. It is loose, friable, worthless in itself. Raise it in capacity to cast-iron, wrought-iron, steel, it becomes a highway for the commerce of nations, over the mountains and under them. It becomes bones, muscles, body for the inspiring soul of steam. It holds up the airy bridge over the deep chasm. It is obedient in your hand as blade, hammer, bar, or spring. It is inspirable by electricity, and bears human hopes, fears, and loves in its own bosom. It has been raised from valueless ore. Change it again to something as far above steel as that is above ore. Change all earthly ores to highest possibility; string them to finest tissues, and the new result may fit God's hand as tools, and thrill with his wisdom and creative processes, a body fitted for God's spirit as well as the steel is fitted to your hand. From this world take opacity, gravity, darkness, bring in more mind, love, and God, and then we will have heaven. An immanent God makes a plastic world.

When man shall have mastered the forces that now exist, the original Creator and Sustainer will say, "Behold, I create all things new." Nature shall be called nearer to God, be more full of his power. To the long-wandering æneas, his divine mother sometimes came to cheer his heart and to direct his steps. But the goddess only showed herself divine by her departure; only when he stood in desolation did the hero know he had stood face to face with divine power, beauty, and love. Not so the Christian scholars, the wanderers in Nature's bowers to-day. In the first dawn of discovery, we see her full of beauty and strength; in closer communion, we find her full of wisdom; to our perfect knowledge, she reveals an indwelling God in her; to our ardent love, she reveals an indwelling God in us.

But the evidence of the progressive refinements of habitation is no more clear than that of progressive refinement of the inhabitant: there must be some one to use these finer things. An empty house is not God's ideal nor man's. The child may handle a toy, but a man must mount a locomotive; and before there can be New Jerusalems with golden streets, there must be men more avaricious of knowledge than of gold, or they would dig them up; more zealous for love than jewels, or they would unhang the pearly gates. The uplifting refinement of the material world has been kept back until there should appear masterful spirits able to handle the higher forces. Doors have opened on every side to new realms of power, when men have been able to wield them. If men lose that ability they close again, and shut out the knowledge and light. Then ages, dark and feeble, follow.

Some explore prophecy for the date of the grand transformation of matter by the coming of the Son of Man, for a new creation. A little study of nature would show that the date cannot be fixed. A little study of Peter would show the same thing. He says, "What manner of persons ought ye to be, in all holy conversation and godliness, looking for and hastening the coming of the day of God, wherein the heavens being on fire shall be dissolved, and the elements shall melt with fervent heat? Nevertheless we, according to his promise, look for a new heaven and a new earth."

The idea is, that the grand transformation of matter waits the readiness of man. The kingdom waits the king. The scattered cantons of Italy were only prostrate provinces till Victor Emanuel came, then they were developed into united Italy. The prostrate provinces of matter are not developed until the man is victor, able to rule there a realm equal to ten cities here. Every good man hastens the coming of the day of God and nature's renovation. Not only does inference teach that there must be finer men, but fact affirms that transformation has already taken place. Life is meant to have power over chemical forces. It separates carbon from its compounds and builds a tree, separates the elements and builds the body, holds them separate until life withdraws. More life means higher being. Certainly men can be refined and recapacitated as well as ore. In Ovid's "Metamorphoses" he represents the lion in process of formation from earth, hind quarters still clay, but fore quarters, head, erect mane, and blazing eye—live lion—and pawing to get free. We have seen winged spirits yet linked to forms of clay, but beating the celestial air, endeavoring to be free; and we have seen them, dowered with new sight, filled with new love, break loose and rise to higher being.

In this grand apotheosis of man which nature teaches, progress lias already been made. Man has already outgrown his harmony with the environment of mere matter. He has given his hand to science, and been lifted up above the earth into the voids of infinite space. He has gone on and on, till thought, wearied amidst the infinities of velocity and distance, has ceased to note them. But he is not content; all his faculties are not filled. He feels that his future self is in danger of not being satisfied with space, and worlds, and all mental delights, even as his manhood fails to be satisfied with the materiel toys of his babyhood. He asks for an Author and Maker of things, infinitely above them. He has seen wisdom unsearchable, power illimitable; but he asks for personal sympathy and love. Paul expresses his feeling: every creature—not the whole creation—groaneth and travaileth in pain together until now, waiting for the adoption—the uplifting from orphanage to parentage—a translation out of darkness into the kingdom of God's dear Son. He hears that a man in Christ is a new creation: old things pass away, all things become new. There is then a possibility of finding the Author of nature, and the Father of man. He begins his studies anew. Now he sees that all lines of knowledge converge as they go out toward the infinite mystery; sees that these converging lines are the reins of government in this world; sees the converging lines grasped by an almighty hand; sees a loving face and form behind; sees that these lines of knowledge and power are his personal nerves, along which flashes his will, and every force in the universe answers like a perfect muscle.

Then he asks if this Personality is as full of love as of power. He is told of a tenderness too deep for tears, a love that has the Cross for its symbol, and a dying cry for its expression: seeking it, he is a new creation. He sees more wondrous things in the Word than in the world. He comes to know God with his heart, better than he knows God's works by his mind.

Every song closes with the key-note with which it began, and the brief cadence at the close hints the realms of sound through which it has tried its wings. The brief cadence at the close is this: All force runs back into mind for its source, constant support, and uplifts into higher grades.

Mr. Grove says, "Causation is the will, creation is the act, of God." Creation is planned and inspired for the attainment of constantly rising results. The order is chaos, light, worlds, vegetable forms, animal life, then man. There is no reason to pause here. This is not perfection, not even perpetuity. Original plans are not accomplished, nor original force exhausted. In another world, free from sickness, sorrow, pain, and death, perfection of abode is offered. Perfection of inhabitant is necessary; and as the creative power is everywhere present for the various uplifts and refinements of matter, it is everywhere present with appropriate power for the uplifting and refinement of mind and spirit.

SUMMARY OF LATEST DISCOVERIES AND CONCLUSIONS.

Movements on the Sun.—The discovery and measurement of the up-rush, down-rush, and whirl of currents about the sunspots, also of the determination of the velocity of rotation by means of the spectroscope, as described (page 53), is one of the most delicate and difficult achievements of modern science.

Movement of Stars in Line of Sight (page 51).—The following table shows this movement of stars, so far as at present known:

Sun's Appearance.—This was formerly supposed to be an even, regular, dazzling brightness, except where the spots appeared. But the sun's surface is now known to be mottled with what are called rice grains or willow leaves. But the rice grains are as large as the continent of America. The spaces between are called pores. They constitute an innumerable number of small spots. This appearance of the general surface is well portrayed in the cut on page 92.

Close Relation between Sun and Earth.-Men always knew that the earth received light from the sun. They subsequently discovered that the earth was momentarily held by the power of gravitation. But it is a recent discovery that the light is one of the principal agents in chemical changes, in molecular grouping and world-building, thus making all kinds of life possible (p. 30-36). The close connection of the sun and the earth will be still farther shown in the relation of sun-spots and auroras. One of the most significant instances is related on page 19, when the earth felt the fall of bolides upon the sun. Members of the body no more answer to the heart than the planets do to the sun.

Hydrogen Flames.—It has been demonstrated that the sun flames 200,000 miles high are hydrogen in a state of flaming incandescence (page 85).

Sun's Distance.—The former estimate, 95,513,794 miles, has been reduced by nearly one-thirtieth. Lockyer has stated it as low as 89,895,000 miles, and Proctor, in "Encyclopædia Britannica," at 91,430,000 miles, but discovered errors show that these estimates are too small. Newcomb gives 92,400,000 as within 200,000 miles of the correct distance. The data for a new determination of this distance, obtained from the transit of Venus, December 8th, 1874, have not yet been deciphered; a fact that shows the difficulty and laboriousness of the work. Meanwhile it begins to be evident that observations of the transit of Venus do not afford the best basis for the most perfect determination of the sun's distance.

Since the earth's distance is our astronomical unit of measure, it follows that all other distances will be changed, when expressed in miles, by this ascertained change of the value of the standard.

Oxygen in the Sun.—In 1877 Professor Draper announced the discovery of oxygen lines in the spectrum of the sun. The discovery was doubted, and the methods used were criticised by Lockyer and others, but later and more delicate experiments substantiate Professor Draper's claim to the discovery. The elements known to exist in the sun are salt, iron, hydrogen, magnesium, barium, copper, zinc, cromium, and nickel. Some elements in the sun are scarcely, if at all, discoverable on the earth, and some on the earth not yet discernible in the sun.

Substance of Stars.—Aldebaran (Frontispiece) shows salt, magnesium, hydrogen, calcium, iron, bismuth, tellurium, antimony, and mercury. Some of the sun's metals do not appear. Stars differ in their very substance, and will, no doubt, introduce new elements to us unknown before.

The theory that all nebulæ are very distant clusters of stars is utterly disproved by the clearest proof that some of them are only incandescent gases of one or two kinds.

Discoveries of New Bodies.—Vulcan, the planet nearest the sun (page 138). The two satellites of Mars were discovered by Mr. Hall, U. S. Naval Observatory, August 11th, 1877 (page 161). "The outer one is called Diemas; the inner, Phobus.

Sir William Herschel thought he discovered six satellites of Uranus. The existence of four of them has been disproved by the researches of men with larger telescopes. Two new ones, however, were discovered by Mr. Lassell in 1846.

Saturn's Rings are proved to be in a state of fluidity and contraction (page 171).

Meteors and Comets.—The orbits of over one hundred swarms of meteoric bodies are fixed: their relation to, and in some cases indentity with, comets determined. Some comets are proved to be masses of great weight and solidity (page 133).

Aerolites.-Some have a texture like our lowest strata of rocks. There is a geology of stars and meteors as well as of the earth. M. Meunier has just received the Lalande Medal from the Paris Academy for his treatise showing that, so far as our present knowledge can determine, some of these meteors once belonged to a globe developed in true geological epochs, and which has been separated into fragments by agencies with which we are not acquainted.

The Horizontal Pendulum.—This delicate instrument is represented in Fig. 82. It consists of an upright standard, strongly braced; a weight, m, suspended by the hair-spring of a watch, B D, and held in a horizontal position by another watch-spring, A C. The weight is deflected from side to side by the slightest influence. The least change in the level of a base thirty-nine inches long that could be detected by a spirit-level is 0".1 of an arc—equal to raising one end 1/2068 of an inch. But the pendulum detects a raising of one end 1/36000000 of an inch. To observe the movements of the pendulum, it is kept in a dark room, and a ray of light is directed to the mirror, m, and thence reflected upon a screen. Thus the least movement may be enormously magnified, and read and measured by the moving spot on the screen. It has been discovered that when the sun rises it has sufficient attraction to incline this instrument to the east; when it sets, to incline it to the west. The same is true of the moon. When either is exactly overhead or underfoot, of course there is no deflection. The mean deflection caused by the moon at rising or setting is 0".0174; by the sun, 0".008. Great results are expected from this instrument hardly known as yet: among others, whether gravitation acts instantly or consumes time in coming from the sun. This will be shown by the time of the change of the pendulum from east to west when the sun reaches the zenith, and vice versa when it crosses the nadir. The sun will be best studied without light, in the quiet and darkness of some deep mine.

Light of Unseen Stars.—From careful examination, it appears that three-fourths of the light on a fine starlight night comes from stars that cannot be discerned by the naked eye. The whole amount of star light is about one-eightieth of that of the full moon.

Lateral Movements of Stars, page 226-28.

Future Discoveries—A Trans-Neptunian Planet.—Professor Asaph Hall says: "It is known to me that at least two American astronomers, armed with powerful telescopes, have been searching quite recently for a trans-Neptunian planet. These searches have been caused by the fact that Professor Newcomb's tables of Uranus and Neptune already begin to differ from observation. But are we to infer from these errors of the planetary tables the existence of a trans-Neptunian planet? It is possible that such a planet may exist, but the probability is, I think, that the differences are caused by errors in the theories of these planets. * * * A few years ago the remark was frequently made that the labors of astronomers on the solar system were finished, and that henceforth they could turn their whole attention to sidereal astronomy. But to-day we have the lunar theory in a very discouraging condition, and the theories of Mercury, Jupiter, Saturn, Uranus, and Neptune all in need of revision; unless, indeed, Leverrier's theories of the last two planets shall stand the test of observation. But, after all, such a condition of things is only the natural result of long and accurate series of observations, which make evident the small inequalities in the motions, and bring to light the errors of theory."

Future discoveries will mostly reveal the laws and conditions of the higher and finer forces. Already Professor Loomis telegraphs twenty miles without wire, by the electric currents between mountains. We begin to use electricity for light, and feel after it for a motor. Comets and Auroras show its presence between worlds, and in the interstellar spaces. Let another Newton arise.

SOME ELEMENTS OF THE SOLAR SYSTEM

EXPLANATION OF ASTRONOMICAL SYMBOLS.

SIGNS OF THE ZODIAC

OTHER ABBREVIATIONS USED IN THE ALMANAC.

S., South, i.e., crosses the meridian; M., morning; A, Afternoon; Gr. H. L. N., greatest heliocentric latitude north, i.e., greatest distance north of the ecliptic, as seen from the sun. conjunction Mercury Sun Inf., inferior conjunction; Sup., superior conjunction.

GREEK ALPHABET USED INDICATING THE STARS.

CHAUTAUQUA OUTLINE FOR STUDENTS.

As an aid to comprehension, every student should draw illustrative figures of the various circles, planes, and situations described. (For example, see Fig. 45, page 112.) As an aid to memory, the portion of this outline referring to each chapter should be examined at the close of the reading, and this mere sketch filled up to a perfect picture from recollection.

I. Creative Processes.—The dial-plate of the sky. Cause or different weights—on sun, moon. Two laws of gravity. Inertia. Fall of earth to sun per second. Forward motion. Elastic attraction. Perturbation of moon; of Jupiter and Saturn. Oscillations of planets.

II. Light.—From condensation. Number of vibrations of red; violet. Thermometer against air. Aerolite against earth. Two bolides against the sun. Large eye. Velocity of light. Prism. Color means different vibrations. Music of light. Light reports substance of stars. Force of; bridge, rain, dispersion, intensities, reflection, refraction, decomposition.

III. Astronomical Instruments.—Refracting telescope. Reflecting; largest. Spectroscope. Spectra of sun, hydrogen, sodium, etc. E made G by approach; C by departure. Stars approach and recede.

IV. Celestial Measurements.-Place and time by stars. Degrees, minutes, seconds. Mapping stars. Mural circle. Slow watch. Hoosac Tunnel. Fine measurements. Sidereal time. Spider-lines. Personal equation. Measure distance—height. Ten-inch base line. Parallax of sun, stars. Longitude at sea. Distance of Polaris, α Centauri, 61 Cygni. Orbits of asteroids.

V. The Sun.—World on fire. Apparent size from planets. Zodiacal light. Corona. Hydrogen—how high? Size. How many earths? Spots: 1. Motion; 2. Edges; 3. Variable; 4. Periodic; 5. Cyclonic; 6. Size; 7. Velocities. What the sun does. Experiments.

VI. The Planets from Space.—North Pole. Speed. Sizes. Axial revolution. Man's weight on. Seasons. Parallelism of axis. Earth near sun in winter. Plane of ecliptic. Orbits inclined to. Earth rotates. Proof. Sun's path among stars. Position of planets. Motion—direct, retrograde. Experiments.

VII. Meteors.—Size; number; cause of; above earth; velocity; colors; number in space; telescopic view of. Aerolites: Systems of; how many known. Comets: Orbits; number of comets; Halley's; Biela's lost; Encke's. Resisting medium. Whence come comets? Composed of what? Amount of matter in. Earth.

VIII. The Planets.—How many? Uranus discovered? Neptune? Asteroids? Vulcan? Distance from sun. Periodic time. Mercury: Elements; shapes, as seen from earth; transits. Venus: Elements; seen by day; how near earth? how far from? phases; Galileo. Earth: Elements; in space; Aurora; balance of forces. Tides: Main and subsidiary causes; eastern shores; Mediterranean Sea. Moon: Elements; hoax; moves east; see one side; three causes help to see more than half. Revolution: Why twenty-nine and a half days: heat—cold; how much light? Craters and peaks lighted; measured. Eclipses—Why not every new and full moon? Periodicity. Mars: Elements; how near earth? How far from? Apparent size; ice-fields; which end most? Satellites—Asteroids: How found? When? By whom? How many? Jupiter: Elements; trade-winds; how much light received? Own heat. Satellites: How many? Colors. Saturn: Elements; habitability; rings; flux; satellites. Uranus: Elements; discoverer; seen by; moon's motion. Neptune: Elements; discovered by; how? Review system.

IX. The Nebular Hypothesis.—State it; facts confirmatory. Objections—1. Heat; 2. Rotation; 3. Retrograde; 4. Martial moons; 5. Star of 1876. Evolution: Gaps in; conclusion.

X. The Stellar System.-Motto. Man among stars; open page; starry poem; stars located; named. Thuban. Etanin. Constellations: Know them; number of stars; double; ε Lyræ, Sirius, Procyon, Castor, 61 Cygni, γ Virginis. Colored stars; change color. Clusters: Two theories. Nebulæ: Two visible; composed of; shapes; where? Variable stars. Sun. β Lyræ, Mira, Betelguese, Algol; cause. Temporary; 1572. New star of 1866: Two theories. Star of 1876. Movements of stars; Sirius; sun; 1830 Groombridge. Stars near Pleiades: Orion, Great Dipper, Southern Cross. Centre of gravity.

XI. The Worlds and the Word.—Rich. Number. Erroneous allusions. Truth before discovery: 1. A beginning; 2. Creation before arrangement; 3. Light before sun; 4. Mountains under water; 5. Order of development; 6. Sphere of earth; 7. How upheld; 8. Number of stars; 9. Weight of air; 10. Meteorology; 11. Queries to Job; 12. Sun to end of heaven; 13. View of Mitchell; 14. Herschel. What is matter? Force? End of earth. Way to knowledge. Work of light. Transfiguration of matter. Uniformitarianism. A whisper of Him. Man for mastery. Each a type of higher. Survival of fittest. Uranus. Worlds and Word one language.

XII. The Ultimate Force.—Universe shows power: 1. Rain; Niagara; 2. Vegetable growth; 3. Worlds carried; 4. Sun; fill dome with worlds; 5. Double suns; 6. Galaxies. Correlation. What ultimate? Mind and will. What continuous relation? Watch. Theories of gravitation: Newton's, Le Sage's, Bible's. High-class energy deteriorates. Search for atoms: 1. Microscope; 2. Gold; 3. Infusoria; 4. Musk. Properties of atoms: 1. Impenetrable; 2. Indivisible; 3. Shape; 4. Quality; 5. Crystallization; 6. Not touch each other; 7. Active; 8. Attractive; 9. Intelligent. Whose? Relation of matter to God; rock to soil. Push upward. Highest has mastery. Man advances by highest. Matter recapacitated. Refined habitations. Inhabitants. All force leads back to mind. Personal and infinite.

GLOSSARY OF ASTRONOMICAL TERMS AND INDEX.

Abbreviations used in astronomies, 275.

Aberration of light (a wandering away), an apparent displacement of a star, owing to the progressive motion of light combined with that of the earth and its orbit, 199.

Aerolite (air-stone), 122.

Air, refraction of the, 40.

Algol, the variable star, 222.

Almanac, Nautical, 71; explanation of signs used, 275.

Alphabet, Greek, 275.

Altitude, angular elevation of a body above the horizon.

Angle, difference in directions of two straight lines that meet.

Annular (ring-shaped) eclipses, 158; nebulæ, 218, 220.

Aphelion, the point in an orbit farthest from the sun.

Apogee, the point of an orbit which is farthest from the earth.

Apsis, plural apsides, the line joining the aphelion and perihelion points; or the major axis of elliptical orbits.

Arc, a part of a circle.

Ascension, right, the angular distance of a heavenly body from the first point of Aries, measured on the equator.

Asteroids (star-like), 162; orbits of interlaced, 74.

Astronomical instruments, 43.

Astronomy, use of, 57.

Atom, size of, 255; power of, 256.

Aurora Borealis, 143.

Axis, the line about which a body rotates.

Azimuth, the angular distance of any point or body in the horizon from the north or south points.

Bailey's beads, dots of light on the edge of the moon seen in a solar eclipse, caused by the moon's inequalities of surface.

Base line, 68.

Biela's comet, 129.

Binary system, a double star, the component parts of which revolve around their centre of gravity.

Bode's law of planetary distances is no law at all, but a study of coincidences.

Bolides, small masses of matter in space. They are usually called meteors when luminous by contact with air, 120.

Celestial sphere, the apparent dome in which the heavenly bodies seem to be set; appears to revolve, 3.

Centre of gravity, the point on which a body, or two or more related bodies, balances.

Centrifugal force (centre fleeing).

Chromolithic plate of spectra of metals, to face 50.

Circumpolar stars, map of north, 201.

Colors of stars, 214.

Colures, the four principal meridians of the celestial sphere passing from the pole, one through each equinox, and one through each solstice.

Comets, 126; Halley's, 128; Biela's lost, 129; Encke's, 130; constitution of, 131; will they strike the earth? 133.

Conjunction. Two or more bodies are in conjunction when they are in a straight line (disregarding inclination of orbit) with the sun. Planets nearer the sun than the earth are in inferior conjunction when they are between the earth and the sun; superior conjunction when they are beyond the sun.

Constellation, a group of stars supposed to represent some figure: circumpolar, 201; equatorial, for December, 202; for January, 203; April, 204; June, 205; September, 206; November, 207; southern circumpolar, 208.

Culmination, the passage of a heavenly body across the meridian or south point of a place; it is the highest point reached in its path.

Cusp, the extremities of the crescent form of the moon or an interior planet.

Declination, the angular distance of a celestial body north or south from the celestial equator.

Degree, the 1/360 part of a circle.

Direct motion, a motion from west to east among stars.

Disk, the visible surface of sun, moon, or planets.

Distance of stars, 70.

Double stars, 210.

Earth, revolution of, 109; in space, 142; irregular figure, 145.

Eccentricity of an ellipse, the distance of either focus from centre divided by half the major axis.

Eclipse (a disappearance), 157.

Ecliptic, the apparent annual path of the sun among the stars; plane of, 106.

Egress, the passing of one body off the disk of another.

Elements, the quantities which determine the motion of a planet: data for predicting astronomical phenomena; table of solar, 274.

Elements, chemical, present in the sun, 270.

Elongation, the angular distance of a planet from the sun.

Emersion, the reappearance of a body after it has been eclipsed or occulted by another.

Equator, terrestrial, the great circle half-way between the poles of the earth. When the plane of this is extended to the heavens, the line of contact is called the celestial equator.

Equinox, either of the points in which the sun, in its apparent annual course among the stars, crosses the equator, making days and nights of equal length.

Evolution, materialistic, 182; insufficient, 189.

Fizeau determines the velocity of light, 23.

Forces, delicate balance of, 144.

Galileo, construction of his telescope, 43.

Geocentric, a position of a heavenly body as seen or measured from the earth's centre.

Geodesy, the art of measuring the earth without reference to the heavenly bodies.

God, relation of, to the universe, 258.

Gravitation, laws of, 6; extends to the stars, 13; theories of, 253.

Gravity on different bodies, 6, 274.

Helical, rising or setting of a star, as near to sunrise or sunset as it can be seen.

Heliocentric, as seen from the centre of the sun.

Hoosac Tunnel, example of accuracy, 62.

Horizontal pendulum, 272.

Immersion, the disappearance of one body behind another, or in its shadow.

Inclination of an orbit, the angle between its plane and the plane of the ecliptic.

Inferior conjunction, when an interior planet is between the earth and the sun.

Jupiter, apparent path of, in 1866, 112; elements of, 164; satellites of, 165; positions of satellites, 166; elements of satellites, 166; the Jovian system, 167.

Kepler's Laws—1st, that the orbits of planets are ellipses, having the sun or central body in one of the foci; 2d, the radius-vector passes over equal spaces in equal times; 3d, the squares of the periodic times of the planets are in proportion to the cubes of their mean distances from the sun.

Latitude, the angular distance of a heavenly body from the ecliptic.

Light, the child of force, 17; number of vibrations of, 18, 25; velocity of, 22; undulatory and musical, 26; chemical force of, 30; experiments with, 37; approach and departure of a light-giving body measured, 51; aberration of, 199.

Limb, the edge of the disk of the moon, sun, or a planet.

Longitude. If a perpendicular be dropped from a body to the ecliptic, its celestial longitude is the distance of the foot of the perpendicular from the vertical equinox, counted toward the east; mode of ascertaining terrestrial, 72.

Magellanic clouds, 208.

Mars, 159; snow spots of, 160; satellites of, 161.

Mass, the quantity of matter a body contains.

Mean distance of a planet, half the sum of the aphelion and perihelion distances.

Measurements, celestial, 57.

Mercury, 138.

Meridian, terrestrial, of a place, a great circle of the heavens passing through the poles, the zenith, and the north and south points of the horizon; celestial, any great circle passing from one pole to the other.

Meteors, 119; swarm of, meeting the earth, 118; explosion of, 120; systems of, 123; relation of, to comets, 124.

Micrometer, any instrument for the accurate measurement of very small distances or angles.

Mind, origin of force, 252; continuous relation of, to the universe, 252.

Milky Way, 210, 215.

Mira, the Wonderful, 221.

Moon, the, 151; greatest and least distance from the earth, 10; telescopic appearance of, 155.

Mural circle, 61.

Nadir, the point in the celestial sphere directly beneath our feet, opposite to zenith.

Nebulæ, 217.

Nebular hypothesis, not atheistic, 182; stated, 182; confirmatory facts, 183; objections to, 185.

Neptune, elements of, 175.

Node, the point in which an orbit intersects the ecliptic, or other plane of reference; ascending, descending, line of, 107.

Occultation, the hiding of a star, planet, or satellite by the interposition of a nearer body of greater angular magnitude.

Opposition. A superior planet is in opposition when the sun, earth, and the planet are in a line, the earth being in the middle.

Orbit, the path of a planet, comet, or meteor around the sun, or of a satellite around a primary; inclination of, 106; earth's, seen from the stars, 70.

Outline for students, 276.

Parallax, the difference of direction of a heavenly body as seen from two points, as the centre of the earth and some point of its surface, 69.

Parallels, imaginary circles on the earth or in the heavens parallel to the equator, having the poles for their centre.

Perigee, nearest the earth; said of a point in an orbit.

Perihelion, the point of an orbit nearest the sun.

Periodic time, time of a planet's, comet's, or satellite's revolution.

Personal equation, 65.

Perturbation, the effect of the attractions of the planets or other bodies upon each other, disturbing their regular motion; of Saturn and Jupiter, 11; of asteroids, 13; of Uranus and Neptune, 176.

Phases, the portions of the illuminated half of the moon or interior planet, as seen from the earth, called crescent, full, and gibbous.

Photosphere of the sun, 89.

Planet (a wanderer), as seen from space, 99; speed of, 101; size of, 102; movements retrograde and direct, 112.

Pointers, the, 197.

Pole, North, movement of, 198.

Poles, the extremities of an imaginary line on which a celestial body rotates.

Quadrant, the fourth part of the circumference of a circle, or 90°.

Quadrature, a position of the moon or other body when 90° from the sun.

Radiant point, that point of the heavens from which meteors seem to diverge, 118.

Radius-vector, an imaginary line joining the sun and a planet or comet in any part of its orbit.

Rain, weight of, 249.

Reflecting telescope, 44.

Refracting telescope, 43.

Refraction, a bending of light by passing through any medium, as air, water, prism.

Retrograde motion, the apparent movement of a planet from east to west among the stars.

Revolution, the movement of bodies about their centre of gravity.

Rotation, the motion of a body around its axis.

Satellites, smaller bodies revolving around planets and stars.

Saturn, elements of, 167; revolution of, 168; rings of, 169; decreasing, 171; nature of, 171; satellites of, 172.

Seasons, of the earth, 102; of other planets, 105.

Selenography (lunography), a description of the moon's surface.

Signs of the zodiac, the twelve equal parts, of 30° each, into which the zodiac is divided.

Solar system, view of, 100, 177.

Solstices, those points of the ecliptic which are most distant from the equator. The sun passes one about June 21st, and the other about December 21st, giving the longest days and nights.

Spectroscope, 46.

Spectrum of sun and metals, 50.

Stars, chemistry of, 28; distance of, 70-73; mode of naming, 196; number of, 210; double and multiple, 210; colored, 214; clusters of, 215; variable, 220; temporary, new, and lost, 223; movements of lateral, 226; in line of sight, 269.

Stationary points, places in a planet's orbit at which it has no motion among the stars.

Stellar system, the, 195.

Summary of recent discoveries, 269.

Sun, fall of two meteoric bodies into, 19; light from contraction of, 20; as seen from planets, 79; corona, 81; hydrogen flames of, 84; condition of, 89; spots, 90; experiments, 95; apparent path among the stars, 111; power of, 250.

Symbols used in astronomy, 275.

Telescope, refracting, 43; reflecting, 44; Cambridge equatorial, 46.

Telescopic work, clusters, 210; double stars, 212.

Temporary stars, 223.

Terminator, the boundary-line between light and darkness on the moon or a planet.

Tides, 146.

Transit, the passage of an object across some fixed line, as the meridian, or between the eye of an observer and an apparently larger object, as that of Mercury or Venus over the disk of the sun, and the satellites of Jupiter over its disk; of a star, 65.

Ultimate force, the, 249.

Uranus, elements of, 173; moons of, retrograde, 174; perturbed by Neptune, 176.