Chapter II: Section II: Geometrical Astronomy and Astronomical Instruments

By A. Fowler, A.R.C.S., F.R.A.S.

I. THE EARTH AND ITS ROTATION 41
II. THE EARTH’S REVOLUTION ROUND THE SUN 55
III. HOW THE POSITIONS OF THE HEAVENLY BODIES ARE DEFINED 65
IV. THE EARTH’S ORBIT 72
V. MEAN SOLAR TIME 78
VI. THE MOVEMENTS OF THE MOON 87
VII. MOVEMENTS OF PLANETS, SATELLITES, AND COMETS 98
VIII. ECLIPSES AND OCCULTATIONS 110
IX. HOW TO FIND OUR SITUATION ON THE EARTH 122
X. THE EXACT SIZE AND SHAPE OF THE EARTH 129
XI. THE DISTANCES AND DIMENSIONS OF THE HEAVENLY BODIES 139
XII. THE MASSES OF CELESTIAL BODIES 151
XIII. GRAVITATIONAL EFFECTS OF SUN AND MOON UPON THE EARTH 162
XIV. INSTRUMENTAL MEASUREMENT OF ANGLES AND TIME 171
XV. TELESCOPES 176
XVI. INSTRUMENTS OF PRECISION 198
XVII. ASTROPHYSICAL INSTRUMENTS 211

SECTION III.—THE SOLAR SYSTEM.
By Agnes M. Clerke.

I. THE SOLAR SYSTEM AS A WHOLE 229
II. THE SUN 237
III. THE SUN’S SURROUNDINGS 253
IV. THE INTERIOR PLANETS 273
V. THE EARTH AND MOON 283
VI. THE PLANET MARS 297
VII. THE ASTEROIDS 310
VIII. THE PLANET JUPITER 318
IX. THE SATURNIAN SYSTEM 333
X. URANUS AND NEPTUNE 343
XI. FAMOUS COMETS 352
XII. NATURE AND ORIGIN OF COMETS 368
XIII. METEORITES AND SHOOTING STARS 385

SECTION IV.—THE SIDEREAL HEAVENS.
By J. E. Gore, F.R.A.S.

I. THE STARS AND CONSTELLATIONS 399
II. DOUBLE, MULTIPLE, AND COLOURED STARS 410
III. THE DISTANCES AND MOTIONS OF THE STARS 417
IV. BINARY STARS 431
V. VARIABLE AND TEMPORARY STARS 458
VI. CLUSTERS AND NEBULÆ 497
VII. THE CONSTRUCTION OF THE HEAVENS 538

LIST OF ILLUSTRATIONS

_Frontispiece to Volume_—PHOTOGRAPH OF THE MOON.

SECTION I.—HISTORY.
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_Frontispiece_—THE OBSERVATORY AT NICE 2