Part 48

Planets, 39. inferior, 130. periods of, 132. phases of, 132. inner group of, 221. intra-Mercurial, 230. minor, 223. outer group of, 222, 244. superior, 134. motion of, 134. periods of, 137. phases of, 137. three groups of, 221.

Pleiades, the, 328, 342, 351.

Pointers, the, 330.

Polar distance, 16.

Pole Star, the, 7, 330, 365.

Poles, celestial, 7, 9.

Pollux, star in Gemini, 340, 370.

Præsepe, or the Beehive, 350.

Precession of equinoxes, 31, 85.

Prime vertical, the, 12.

Proctor's theory of the stellar universe, 398.

Procyon, star in Canis Minor, 340.

Ptolemaic system, the, 41.

Quadrature, 91, 137.

Radiant point (meteors), 310.

Radius vector, 47.

Refraction, 35.

Regulus, star in Leo, 334, 370.

Rhea, moon of Saturn, 259.

Rigel, star in Orion, 340, 370.

Right ascension, 16.

Sagittarius, or the Archer, 347.

Saturn, apparent size of, 256. distance of, 256. orbit of, 255. periods of, 256. physical constitution of, 257. ring of, 261. changes in, 268. constitution of, 269. phases of, 263. rotation of, 258. satellites of, 259. volume of, 256.

Scorpio, or the Scorpion, 347. cluster in, 355.

Seasons, the, 64.

Sirius, the Dog-Star, 340, 342, 365, 370, 371.

Solar system, the, 41.

Solstices, 29, 59, 60.