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decrease in size and close in behind him, forming clusters and groups which constantly change as he passes along; so, as our earth travels with the solar system on its immense sidereal journey, the stars will grow larger and brighter in front, while those behind us will appear smaller and dimmer. Since, in addition to this, the stars themselves are in motion with varying velocity and in different directions, the constellations must change still more rapidly, so as ultimately to transform entirely the appearance of the heavens. In time, the "bands of Orion" will be loosened, and the "Seven Sisters" will glide apart into remote space. Such are the distances however, that, although these movements have been going on constantly, yet since the creation of man no variation has occurred that is perceptible, save to the watchful astronomer. Nothing in nature is as invariable as the stars. They are the standards of time. Myriads of years must elapse before new starmaps will be required. We need not, then, allow any fear of confusion to disturb us while we study the sky as it is.

VALUE OF THE STARS IN PRACTICAL LIFE. "The stars are the landmarks of the universe." They seem to be placed in the heavens by the Creator, not alone to elevate our thoughts and expand our conceptions of the infinite and eternal, but to afford us, amid the constant fluctuations of our own earth, something unchangeable and abiding. Every landmark about us is constantly changing, but over all shine the

"eternal stars," each with its place so accurately marked, that to the astronomer and geographer no deception is possible. To the mariner, the heavens become a dial-plate, the figures on its face set with glittering stars, along which the moon travels as a shining hand that marks off the hours with an accuracy no clock can ever rival. Standing on the deck of his vessel, far out at sea, a single observation of the sun or stars decides his location in the waste of waters as accurately as if he were at home, and had caught sight of some old landmark he had known from his boyhood. In all the intricacies of surveying, the stars furnish the only immutable guide. Our clocks vainly strive to keep time with the celestial host. Thus, by a wise provision of Providence, even in the most common affairs of life, are we compelled to look for guidance from the shifting objects of earth up to the heavens above.

THE VIEWS OF THE ANCIENTS.-Standing in the light of our present knowledge, the ideas of the ancients seem almost incredible, and we can hardly understand how they could have been seriously entertained. Anaximenes (550 B. c.) thought that the stars were for ornament, and were nailed like bright studs into the crystalline sphere. Anaxagoras (450 B. C.) considered that they were stones whirled up from the earth by the rapid motion of the ether around us, and that its inflammable properties set them on fire and caused them to shine as stars. Many schools of the Grecian philosophers-the Stoics, Epicu

reans, etc.-believed that they were celestial fires kept alive by matter that constantly streamed up to them from the centre of the heavens. The stars were at one time said to feed on air; at another, to be the breathing holes of the universe.

THREE ZONES OF STARS.-If we recall what was said on page 104, concerning the paths of the stars and appearance of the heavens at different seasons of the year, we shall see that the constellations are naturally divided into three zones. The first embraces those which are visible through the entire year; the second, those whose orbits can be seen only in part on any given night; and the third, those whose paths just graze our southern horizon, or never pass above it.

THE CONSTELLATIONS.

NORTHERN CIRCUMPOLAR CONSTELLATIONS.-These constellations in our latitude are visible every night. They may be easily traced by holding the book up toward the northern sky in such a way that Polaris and the Dipper on the map and in the heavens agree in position, and then locating the other constellations by comparison. As they revolve about Polaris, their places will vary with every successive night through the year. The cut represents them as they are seen at midnight of the winter solstice. At 6 P. M. of that day the right-hand side of the map should be held downward, and the

Big Dipper will be directly below the north star. At 6 A. M. the left-hand side should be at the bottom, and the Dipper will be above Polaris. From day to day this aspect will change, each star coming

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a little earlier to the meridian, or to its position on the preceding night. The rate of this progression is six hours, or 90°, in three months.

Ursa Major is represented under the figure of a great bear. It contains 138 stars visible to the naked eye. The constellation has been celebrated

among all nations. It is remarkable that the shepherds of Chaldea in Asia, and the Iroquois Indians of America, gave to it the same name.

Principal stars.-A noticeable cluster of seven stars-six of the second and one of the fourth magaitude-forms what is familiarly termed "The Dipper." In England it is styled Charles's Wain, from a fancied resemblance to a wagon drawn by three horses tandem. Mizar () has a minute companion, Alcor, which Humboldt tells us could be rarely seen in Europe. A person with good eyesight may now readily detect it. Megrez (5), at the junction of the handle and the bowl, is to be marked particularly, since it lies almost exactly in the colure passing through the autumnal equinox. Dubhe and Merak are termed "The Pointers," since they always point out the polar star. The bear's right fore paw and hinder paw are each marked by two small stars, as shown in the cut; a similar pair nearly in line with these denote the left hinder paw (see, Fig. 76). The pairs are 15° apart.

Mythological history.-Diana had a very beautiful attendant named Callisto. Juno, the queen of heaven, becoming jealous of the maid, transformed her into a bear.

"The prostrate wretch lifts up her head in prayer,
Her arms grow shaggy, and deformed with hair;
Her nails are sharpened into pointed claws,
Her hands bear half her weight and turn to paws.
Her lips, that once would tempt a god, begin
To grow distorted in an ugly grin.

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