118

_Gulliver's Travels_, 224

Hale, G.E., 119, 140

Half moon, 183, 185

Hall, Asaph, 223

Hall, Chester Moor, 115

Halley, Edmund, 91, 255, 264-265, 306

Halley's Comet, 255, 264-265

Haraden Hill, 91

Harvard, 118, 302

Harvest moon, 190-192

Hawaii, 221

Heat rays, 127

Heidelberg, 226, 232

Height of lunar mountains, how determined, 201

Height of objects in sky, estimation of, 196

Helium, 138, 145, 182

Helmholtz, 128, 335

Hercules (constellation), 295

Herod the Great, 101-102

Herodotus, 84

Herschel, A.S., 269

Herschel, Sir John, 92, 322

Herschel, Sir William, 22, 36, 114-115, 204, 213, 235, 283, 292, 308,
319-320, 326-328

Herschelian telescope, 114, 119

Hesper, 109

Hesperus, 150

Hevelius, 111

Hezekiah, 85

Hi, 83

Hindoos, 18

Hipparchus, 106, 177, 290, 311

Ho, 83

Holes in Milky Way, 321-323

Holmes, Oliver Wendell, 213

Homer, 223

Horace, Odes of, 106

Horizon, 159

Horizontal eclipse, 169

Horrox, 44, 151-152

Hour Glass Sea, 212

Huggins, Sir William, 94, 125, 317

Humboldt, 270

"Hunter's moon," 192

Huyghens, 111-112, 240, 242-243

Hyades, 296-297, 307

Hydrocarbon gas, 254

Hydrogen, 94, 131, 138, 140, 144, 156, 182, 254

Ibrahim ben Ahmed, 270

Ice-layer theory:
Mars, 219;
moon, 205, 219

Illusion theory of Martian canals, 219

Imbrium, Mare, 197

Inclination of orbits, 36-37

Indigo (rays of light), 121

Inferior conjunction, 147, 149

Inferior planets, 20, 22, Chap. XIV., 229

Instruments, pre-telescopic, 106-107, 172

International photographic survey of sky, 290-291

Intra-Mercurial planet, 25-26

_Introduction to Astronomy_, 31

Inverted view in astronomical telescope, 116-117

Io, 233-234

Iridum, Sinus, 197

Iron, 145, 254

_Is Mars Habitable?_ 221

Jansen, 108

Janssen, 94, 236, 258

Japetus, 240

Jessenius, 89

Job, Book of, 299

Johnson, S.J., 103, 340

Josephus, 101, 262

Juno, 225

Jupiter, 20, 22-23, 31, 34, 37, 42, 227-228, 230-236, 241, 272, 311;
comet family of, 251-253, 256;
discovery of eighth satellite, 26, 232;
eclipse of, by satellite, 234;
without satellites, 234-235

Jupiter, satellites of, 26, 62, 108, 189, 232-235;
their eclipses, 234-235;
their occultations, 62