0, 293, 295, 305, 309, 310, 318, 319, 327;
he "sweeps" the heavens, 280;
his discovery of Uranus, 281, 287;
his artificial Saturn, 281, 282;
his methods of work with his sister, described, 284;
he founded the science of Astronomy, 287

Hind, 300

Hipparchus, 7, 18, 20, 27, 28, and note, 30, 40, 66, 223, 253;
an explanation of his discovery of the precession of the equinoxes,
27, seq.

Hippocrates, 87

Homeric Cosmogony, 15, _seq._

Hooke, 139, 188, 192, 193, 196, 197, 308

Hopital, Marquis de l', 228

Horkey, Martin, 106

Horrebow, 244

Huxley, Prof., 149

Huyghens, 86, 166, 185

K

Kant, 267, 270

Kelvin, Lord, see Thomson, Sir W.

Kepler, John, 59, 60, 63, 64, 65, 66, 70, 72, 73, 75, 77, 79, 84, 93,
94, 95, 104, 106, 107, 110, 122, 137, 145, 153, 158, 164, 165, 166,
167, 192, 200, 208, 209, 210, 211, 212, 214, 218, 224, 227, 253, 256,
259, 260, 262, 288, 295, 296, 332, 338, 361, 389;
he replaced epicycles by an ellipse, 27;
he was a pupil of Tycho Brahe, 54;
he was a speculator more than an observer, 58;
his personal life, 58, _seq._;
his theories about the numbers and distances of the planets, 60, 62;
he was helped by Tycho, 63;
his main work, 65, _seq._;
he gave up circular motion, 69;
his _Mysterium Cosmographicon_, 105;
his Laws, 71, 74, 173, 174, 176, 179, 180, 206, _seq._

L

Lagrange, 193, 234, 255, 256, 257, 258, 263

Lagrange and Laplace, 258, 266, 395;
they laid the foundations of the planetary theory, 259

Laplace, 68, 193, 218, 234, 255, 261, 262, 267, 268, 269, 270, 272,
288, 301, 317, 384, 385, 390;
his nebular hypothesis, 267, 292;
his _Mecanique Celeste_, 323

Lassell, Mr., 283, 284

Leibnitz, 192, 197, 233

Le Monnier, 319

Leonardo, see Vinci, Leonardo da

Leverrier, 193, 327, 328, 329, 330, 352

Lippershey, Hans, 95

M

Maskelyne, 281

Maxwell, Clerk, 302, 303

Molyneux, 248, 249

Morton, Mr. E.J. C, his Life of Copernicus, 31

N

Newton, Prof. H.A., 347

Newton, Sir Isaac, 7, 30, 79, 138, 139, 144, 145, 149, 153, 157, 158,
165, 166, 167, 174, 176, 184, 187, 188, 189, 191, 192, 194, 196, 198,
199, 201, 213, 216, 219, 220, 221, 224, 226, 227, 228, 233, 242, 253,
255, 256, 274, 288, 317, 340, 378;
his _Principia_, 191, 192, 193, 194, 195, 196, 197, 207, 214, 216, 218,
228, 233, 242, 253;
his early life, 161, _seq._;
his first experiments, 163;
his work at Cambridge, 164;
his