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"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, Epicureans, 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.
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 tbe 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 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.
NORTIIERN CIRCUMPOLAR CONSTELLATIONS.
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.
TJrsa JMEajor is represented under the figure of a great hear. It contains 138 stars visible to the naked eye. The constellation has been celebrated
Principal stars.—A noticeable cluster of seven stars—six of the second and one of the fourth magnitude—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 (S), 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,
And lest the supplicating brute might reach
Some time afterward, Callisto's son, Areas, being out hunting, pursued his mother and was about to transfix her with his uplifted spear, when Jupiter in pity transferred them both to the heavens, and placed them among the constellations as Ursa Major and Ursa Minor.
Ursa Minor is represented under the figure of a small bear. It contains twenty-four stars, of which only three are of the third, and four of the fourth magnitude.
Principal stars.— A cluster of seven stars forms what is termed the "Little Dipper." Three of them are small, and are seen with difficulty. Polaris, at the extremity of the handle, has been known from time immemorial as the North Polar Star. Among the Greeks it was styled Cynosure. Until the mariner's compass came into use, it was the star
"Whose faithful beams conduct the wandering ship
Polaris does not mark the exact position of the pole, since that is about 1£° toward the Pointers. This distance will gradually diminish, until in time it will be only \°: then it will increase again, until in the lapse of ages—12,000 years hence—the bril