Chapter IV: Part IV: The Fixed Stars

PAGES

Division of the Stars into Magnitudes—Division of 219-257
the Stars according to their Spectra—Stars
Larger and Smaller than the Sun—The Distances of
the Stars—Variable Stars—Double and Binary
Stars—Spectroscopic Binaries and how they are
Discovered—Proper Motions of the Stars—Number of
the Stars—New, or Temporary Stars—The Milky
Way—The Nebulæ—The Two Kinds of Nebulæ—Spiral
Nebulæ—The Nebular Hypothesis—Applications of
Photography to Stars and Nebulæ—The
Constellations—How to Learn the
Constellations—Their Antiquity—Description of
the Principal Constellations Visible from the
Northern Hemisphere at Various Times of the Year

INDEX 259

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ILLUSTRATIONS

PAGE

THE LUNAR “CRATER” COPERNICUS _Frontispiece_

PHOTOGRAPH OF SOUTH POLAR 8
REGION OF THE MOON

THE MOON NEAR THE “CRATER” 20
TYCHO

DRAWING OF JUPITER 28

DRAWING OF JUPITER 28

JUPITER 38

SATURN 46

SATURN 46

THE MILKY WAY ABOUT CHI CYGNI 58

THE GREAT SOUTHERN 64
STAR-CLUSTER IN CENTAURI

PHOTOGRAPH OF A GROUP OF 76
SUN-SPOTS

POLAR STREAMERS OF THE SUN, 89
ECLIPSE OF 1889

SOLAR CORONA AT THE ECLIPSE OF 89
1871

MOREHOUSE'S COMET, OCTOBER 15, 96
1908

MOREHOUSE'S COMET, NOVEMBER 96
15, 1908

HEAD OF THE GREAT COMET OF 105
1861

HALLEY'S COMET, MAY 5, 1910 105

THE SIX-TAILED COMET OF 1744 112

SPIRAL NEBULA IN URSA MAJOR (M 124
101)

THE WHIRLPOOL NEBULA IN CANES 124
VENATICI

TRESS NEBULA (N. G. C. 6992) 132
IN CYGNUS

THE GREAT ANDROMEDA NEBULA 140

SPIRAL NEBULA IN CEPHEUS (H. 154
IV. 76)

NEBULOUS GROUNDWORK IN TAURUS 154

NEBULA IN SAGITTARIUS (M. 8) 162

THE GREAT NEBULA IN ORION 180

PHOTOGRAPHS OF MARS 200

SCHIAPARRELLI’S CHART OF 220
MARTIAN “CANALS”

ILLUSTRATIONS IN THE TEXT

THE RATIONAL AND THE SENSIBLE 12
HORIZON

ALTITUDE AND AZIMUTH 14

RIGHT ASCENSION AND 35
DECLINATION

THE ECLIPTIC AND CELESTIAL 51
LATITUDE AND LONGITUDE

HOW THE EARTH CONTROLS THE 75
MOON

THE TIDAL FORCE OF THE MOON 79

REFRACTION 85

DIP OF THE HORIZON 87

SIDEREAL AND SOLAR TIME 93

THE CHANGE OF DAY 101

THE SEASONS 107

PARALLAX OF THE MOON 139

PARALLAX OF THE SUN FROM 141
TRANSIT OF VENUS

SPECTRUM ANALYSIS 147

THE PHASES OF THE MOON 160

ORBITS OF MARS AND THE EARTH 183

ELLIPSE, PARABOLA, AND 203
HYPERBOLA

THE NORTH CIRCUMPOLAR STARS 244

KEY TO NORTH CIRCUMPOLAR STARS 245

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PART I.

THE CELESTIAL SPHERE.

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