FIG. PAGE
DANTE STUDYING. _From a fresco by
Luca Signorelli at Orvieto_ _Frontispiece_
1. The Sun’s Path in the Sky at different Seasons 11
2. The Moon at Sunset, soon after New, and three days old 14
3. Path of Mars among the Stars, 1909 16
4. The Star Sphere 19
5. Synodic and Sidereal Periods 21
STAR MAP 34
THE MOON-GOD OF UR. _From a Cylinder-seal in the British
Museum, date about_ B.C. 2400.
_By permission of the Trustees of the British Museum_ 36
6. The triple Star-sign of the Babylonians 37
7, 8, 9. The young Moon and the Pleiades after
sunset, as seen in Babylon, B.C. 1000 42
10. The Scorpion. _From a Babylonian boundary stone
of about_ B.C. 1120, _set up in the reign
of Nebuchadnezzar I. Now in the British Museum_ 43
11. The Goat with Fishes’ Scales. _From a Babylonian
boundary stone_ 43
THE BOAT OF THE SUN TRAVELLING OVER THE SKY.
_From an ancient Egyptian papyrus. Reproduced
from Flammarion’s Astronomical Myths_ 46
12. The Universe according to Anaximander 59
13. The Universe of Leucippus 63
14. The Universe of Democritus 64
15. The Universe of Pythagoras 71
16. The System of Philolaus: night on Earth 73
17. do. twelve hours later: day on Earth 73
18. Earth and Sun according to Heraclides 74
19. The Spheres of the Sun in the system of Eudoxus 90
20. Method of Aristarchus for finding the Distance of the Sun 108
21. Pekin Observatory 114
22. A Pekin Astrolabe of the thirteenth century A.D.
_From photographs taken in 1888 and published
in the Bulletin de la Société belge d’Astronomie_ 116
23. The Moveable Eccentric 119
24. The Movement of Spica 124
25. The Sun and the Equinox 128
26. The Movement of the Earth’s Axis which is the true cause
of Precession. _From Young’s Manual of Astronomy_,
1902 131
27. Precession of the Equinoxes 133
28. Path of Mars, 1909 139
29. The Epicycle 139
30. A Planet “retrograding” and “in opposition” 140
31. Venus, Mercury, and the Sun 142
32. The Sun’s Deferent 145
33. Apparent Variation in the size of the Sun.
_Photographs taken at Kodaikanal Observatory,
with the spectroheliograph, July 1, 1911, and
Jan. 3, 1912. Actual size of the negative_ 146
34. The Moon’s Epicycle and Deferent 148
35. The Ptolemaic System 151
36. Method (erroneous) of estimating Planetary Distances,
described by Alfraganus 188
37. Earth’s Shadow 192