Chapter III: Section II: Geometrical Astronomy

_Frontispiece_—THE LICK REFRACTOR OF THIRTY-SIX INCHES
APERTURE 40
_Fig._
1.— ROUGH MEASUREMENT OF EARTH’S DIAMETER 43
2.— HORIZONS AT TWO PLACES ON THE EARTH 44
3.— FOUCAULT’S PENDULUM EXPERIMENT 49
4.— SUN’S RAYS—DAY AND NIGHT 52
5.— ATMOSPHERIC REFRACTION 54
6.— APPARENT PATHS OF SUN AT EQUINOXES AND SOLSTICES 56
7.— ABERRATIONAL ORBIT OF A STAR 58
8.— THE SUN’S ALTITUDE IN SUMMER AND WINTER 62
9.— THE SUN’S ALTITUDE AT THE EQUINOXES 63
10.— THE MIDNIGHT SUN 64
11.— ALTITUDE AND AZIMUTH 66
12.— RIGHT ASCENSION, DECLINATION, ETC. 69
13.— ELLIPTIC FORM OF EARTH’S ORBIT 72
14.— THE ELLIPSE 73
15.— HOW TO DRAW AN ELLIPSE 74
16.— ILLUSTRATING KEPLER’S SECOND LAW 76
17.— EFFECT OF OBLIQUITY OF ECLIPTIC UPON THE EQUATION OF TIME 81
18.— THE MOON’S PHASES 90
19.— THE LUNAR MONTH 91
20.— THE MOON’S ROTATION 93
21.— THE MOON’S NODES 94
22.— POSITION OF ECLIPTIC AT SUNSET AT VERNAL EQUINOX 96
23.— MOVEMENT OF AN INTERIOR PLANET 99
24.— MORNING AND EVENING STARS 100
25.— MOVEMENT OF AN EXTERIOR PLANET 103
26.— APPARENT PATHS OF CERES, PALLAS, JUNO, AND VESTA, IN 1896 104
27.— OPPOSITION OF MARS 105
28.— ELEMENTS OF AN ELLIPTIC ORBIT 107
29.— THE EARTH’S SHADOW 110
30.— THE LUNAR ECLIPTIC LIMIT 112
31.— ECLIPSES OF THE SUN 114
32.— DURATION OF A SOLAR ECLIPSE 115
33.— TRACK OF ECLIPSE OF APRIL 16, 1893 117
34.— DETERMINATION OF LATITUDE 124
35.— ANCIENT MODE OF MEASURING LATITUDE 125
36.— TRIANGULATION 132
37.— MOVEMENTS OF THE EARTH’S POLE, 1890–95 138
38.— PARALLAX OF A HEAVENLY BODY 140
39.— DIAMETER OF A HEAVENLY BODY 142
40.— MEASUREMENT OF THE MOON’S DISTANCE 143
41.— RELATIVE DISTANCE OF VENUS 145
42.— THE PARALLAX OF MARS 147
43.— THE TRANSIT OF VENUS 148
44.— THE MOON’S CURVILINEAR PATH 155
45.— THE TIDES 163
46.— NUTATION 169
47.— SECTION OF READING MICROSCOPE 172
48.— THE READING MICROSCOPE 173
49.— THE ACHROMATIC OBJECT-GLASS 177
50.— THE NEWTONIAN REFLECTOR 179
51.— THE CASSEGRAIN REFLECTOR 181
52.— THE PHOTOGRAPHIC TELESCOPE 196
53.— THE MERIDIAN CIRCLE OF THE PARIS OBSERVATORY 203
54.— THE MICROMETER APPLIED TO A BINARY STAR 208
55.— THE SPECTROSCOPE ADAPTED TO THE EYE END OF THE LICK
TELESCOPE 221