Sagittarius, the Archer, 180. Saturn, 47. seeing, 52. through a telescope, 149. Scorpius, the Scorpion, 180. Seasonal twilight chart, Ellis, 201. Seasons: autumn, 74. spring, 74. summer, 75. winter, 74. cycle of the, 75. Earth turning round Sun makes the, 72. experiment to show the, 73. Seeing, an eclipse, 107. the Moon with naked eye, 92. the stars, 121. Sextant, how to use it, 84. Shadow of, the Earth, 109. the Penumbra, 135. the Umbra, 135. Shadows, 135. at the North Pole, 88. Shooting the Sun, 84. Shooting stars, 116. Sighting the North Star, 2. Signalling with the Sun’s rays, 38. Signs, in the almanac, 183. of the Zodiac, 168. Sirius, the Dog Star, 8, 118. Sky, things in the, 107. Smoked Sun glasses, 30. Solar day, 154. apparent, 154. Solar noon, 153. Solar spectrum, 189. Solar system, in perspective, 56. top view of, 55. Solar time, 152. mean, 154. Solstice, summer, 176. winter, 181. Sound waves, 125. South Pole, 26. Spectroscope, 189. how made, 191. Spectrum, 133. solar, 189. Spring, 74. Spyglass, 136. stars seen through, 144. Standard meridians, 86, 156. Standard time, 155. zone system of, 156. Standard time meridians in United States, 159. Starcraft, merit badge for, 193. Star finder, how to make a, 1. Kullmer, 209. Star tests for eyesight, 197. Star time, 160. Star trails, how to make, 187. Stars, colored, 202. constellations having first magnitude, 201. double, 204. first magnitude, 200. how made, 119. how they shine, 121. invisible or dark, 206. magnitude of, 199. near the Sun’s path, 62. photographing, 185. seeing, 121. through a telescope, 149. variable, 205. what they are made of, 188. of the Zodiac, 166. Straight line defined, 194. Summer, 75. Summer solstice, 176. Sun, annular eclipse of the, 87. arctic, 87. attraction of, illustrated, 59. brightest star, 29. hot gases of, 121. chromosphere of, 32. core of, 32. corona of, 33. cross section of, 34. eclipse of, by the Moon, 110. how to see, 29. layers of flame of, 31. lighting a fire with, 37. from the Moon, view of, 104. stars near the, 62. partial eclipse of the, 112. path of the, 46, 170. photographing the, 187. photosphere of, 32. positions of planets round the, 54. prominences of, 31. rays of, signalling with, 38. shooting the, 84. surface of, 32. time marked by, 151. through a telescope, 148. weather and, 34. what it is made of, 30. Sun dial, how to make a simple, 42. Sun spots, 31. effects of, on the Earth, 33.