INDEX TO ASTRONOMY, ii 
Density and distances of the planets, 105. 
Dipleidosecope, the, 172. 
Dollond’s quadrant, 160 ; repeating circle, 162. 
Dominical letter, the, 151. 
Dorpat refractor, description of the, 156. 
Double stars, 94. 
Earth, the, satisfactory proof of the spherical shape 
of, 78; its annual revolution round the sun, 
106 ; its mean distance from the sun, 107 ; 
rotation on its axis, 109, 123 ; inequality of 
the seasons of, 109 ; its spheroidal shape, 124. 
Eccentricity of the planets, 105. 
Eclipses of the sun and moon, 100 ; total eclipse 
of the sun, June 4th, 1788, 122. 
Eeliptic, obliquity of the, 108. 
Egyptians, their knowledge of astronomy, 74; 
planetary system of the, 103. 
Ellipse, properties of the, 97. 
Elliptical orbits of the planets, primary causes 
of the, 114. 
Encke’s comet, 143. 
Epacts, the, 152. 
Equatorial telescope, 164, 
Equinoxes, the, 85, 107. 
Ertel’s theodolite, 165. 
Ether, resistance of the, 130; its influence on 
the motion of comets, 131. 
Fixed stars, 89. 
Fraunhofer, constructor of the Dorpat refractor, 
156. . 
Fritsch of Quedlinburgh, his observations on the 
solar spots, 132. 
Galileo, the discoveries of, 75; observes the 
spots on the sun, 133 ; his telescope, 156. 
Gassendi, first observes a transit of Mercury, 111. 
Geocentric place of the planets, 98. 
Geographical latitude and longitude, definitions 
of, and methods of determining, 86. 
Gnomon, the, known to the Chinese from the 
most remote antiquity, 74; and Gnomonics, 
167, 169. 
Golden number, the, 152. 
Gravitation, law of, discovered by Newton, 75; 
of the planets, 105. 
Gravity, local variation of, 125. 
Greeks, the, astronomy first raised to a higher 
level by, 74. 
Halley, the periods of, 84; first recognises the 
importance of observing the transit of Venus, 
111; his observations on the comet called by 
his name, 143. 
Harriot, discoverer of the spots on the sun, 132. 
Harrison’s compensation pendulum, 170. 
Hele, Peter, the inventor of watches, 169. 
Heliocentric place of the planets, 98. 
Henderson, description of planetarium by, 171. 
Herschel, the discoverer of Uranus, 75; his 
hypothesis with respect to the solar spots, 
132; his great telescope, 158. 
Heteroscii, the, 147. 
Historical survey of astronomy, 74. 
Hipparchus, his contributions to astronomical 
knowledge, 74; names of the constellations 
as given by, 90. 
Horizon, the visible, 85. 
Horizontal parallax, 97. 
Horrox, the first observer of atransit of Venus, 111, 
Irclination of the planetary orbits, 106. 
Inferior planet, illustration of the apparent course 
of an, 80; transit across the sun’s disk, 111. 
Jupiter, moons of, 115; their mean distances, 
periods, &c., 116; description of, 141 ; hypo- 
thetical inhabitants of, 148. 
Kepler, his celebrated laws, 75, 115; confirms 
the system of Copernicus, 103. 
Lambert’s “ Kosmologische Briefe,” 89. 
Latitude of a place, determination of, 86. 
Light of the planets, 105. 
Lohrman, his maps of the moon, 133. 
Longitude of a place, determination of, 86, 
Lunarium, the, 171. 
Madler, his map of the moon, 133; observations 
on Mars and Uranus, 141. 
Magellanic clouds, the, 96. 
Maps, celestial, 93. 
Marius, Simon, discoverer of Jupiter’s moons, 
ey 
Mars, apparent course of, 81 ; description of, 140 ; 
its surface carefully examined by Madler, 141 ; 
its physical condition, 148. 
Mean anomaly, 99. 
Mercury, transit of, 111; principal phases of a 
transit of, 121 ; temperature of, 147. 
Meridian, the first, 87 ; measurement of meridian 
difference, 88; circle, 162. 
Micrometer, the circle and differential, 172. 
Mobius, his model for representing the orbits of 
the asteroids, 172. 
Mock suns and moons, 145. 
Moon, the, her revolution around the earth, 
phases, and nodes, 83 ; eclipses of, 100; ad- 
ditional remarks on the course of, 112; in- © 
clination of her orbit, time of rotation, &c., 
113 ; description of the extent and course of 
the shadow of, during a total eclipse of the 
sun, 122 ; topography of, 133 ; structure of the 
lunar mountains, 138; colors of, 139 ; mock, 
145; its peculiar physical state, 148. 
Motion of the planetary orbits, 106; compound, 
12d: 
Multiple stars, 96. 
Mural quadrant, the, 159. 
Nebulous spots and stars, 95 ; clusters, 144, 
New stars, 96. 
Newton’s discoveries, 75. 
Nodes of the moon, 83. 
Number of the fixed stars, 89. 
Observatories, choice of situation and construc- 
tion of, 172; enumeration of the principal, 
173. 
Olbers, his theory of comets, 142; discovers a 
comet which is named after him, 143. 
Orbits, velocity, fall, inclination, and motion of 
the planetary, 106. 
Orreries, 171. 
Parallax, horizontal, and parallax in altitude, 97 ; 
of a place, 98; only certain method of obtain- 
ing the parallax of the sun, 111. 
Parallelogram of forces, 126, 
Parhelia, 145. 
Parselenia, 145. 
Pastorff, his observations on the solar spots, 132, 
Perigee, definition of, 119. 
Perihelion distance, 99. 
653 
