Chapter IV: Section III: The Solar System

_Frontispiece_—DONATI’S COMET 228

1.— PHOTOGRAPH OF A SUN-SPOT 243
2.— SUN-SPOTS AND MAGNETIC VARIATIONS 246
3.— CURVES SHOWING THE DEVELOPMENT OF SUN-SPOTS 257
4.— ERUPTIVE PROMINENCE 264
5.— THE SAME, 18 MINUTES LATER 265
6.— THE ECLIPSED SUN 267
7.— THE CORONA OF JANUARY 1, 1889 269
8.— MAP OF MERCURY 276
9.— VENUS, FROM A DRAWING BY MASCARI 280
10.— MAP OF THE MOON 291
11.— PHOTOGRAPH OF THE TOTALLY ECLIPSED MOON 296
12.— CHART OF MARS 300
13.— THE “EYE OF MARS” 302
14.— THE OASES OF MARS 304
15.— JUPITER, SHOWING THE RED SPOT 322
16.— PHOTOGRAPH OF JUPITER 328
17.— TRANSIT OF JUPITER’S FIRST SATELLITE 330
18.— SATURN AND HIS RINGS 335
19.— GREAT COMET OF SEPTEMBER, 1882 361
20.— DONATI’S COMET 363
21.— PHOTOGRAPH OF SWIFT’S COMET 374
22.— THE SAME, 24 HOURS LATER 375
23.— PHOTOGRAPH OF HOLMES’ COMET 378
24.— PHOTOGRAPH OF BROOKS’ COMET 381