Croll, Dr., his _Climate and Time_, 264

D

D'Alembert, 193, 234

Darwin, Charles, 134, 138, 397

Darwin, Prof. George, 367, 394

Delambre, 253

Descartes, 145, 146, 148, 151, 153, 156, 158, 164, 165, 167, 178, 181,
224, 227;
his _Discourse on Method_, 142;
his dream, 147;
his system of algebraic geometry, 149, _seq._;
his doctrine of vortices, 151, _seq._;
his _Principia Mathematica_, 154;
his Life by Mr. Mahaffy, 154

E

Earth, the difficulties in the way of believing that it moved, 34, _seq._

"Earth-rise in Moon-land," 258, note

Encke, 345, 346

Epicyclic orbits explained, 23, _seq._

Equinoxes, their precession discovered by Hipparchus, 27

Eudoxus, 19

Euler, 193, 234

F

Faraday, 84

Fizeau, 238, 239

Flamsteed, 215, 246, 284, 308, 319

Fraunhofer, 311

Froude, Prof.; his _Oceania_, 387

G

Galen, 87

Galileo, Galilei, 63, 75, 84, 88, 90, 92, 93, 97, 98, 101, 104, 106, 107,
108, 109, 110, 112, 114, 116, 117, 118, 120, 121, 122, 123, 125, 127,
133, 134, 137, 144, 145, 153, 154, 157, 165, 166, 167, 168, 177, 188,
200, 224, 227, 256, 281, 288, 309, 361;
his youth, 85;
his discovery of the pendulum, 86;
his first observations about falling bodies, 88, _seq._;
he invents a telescope, 95;
he adopts the Copernican theory, 94;
he conceives "earth-shine," 100;
he discovers Jupiter's moons, 103;
he studies Saturn, 114, _seq._;
his _Dialogues on the Ptolemaic and Copernican Systems_, 124;
his abjuration, 130;
he becomes blind, 132;
he discovered the Laws of Motion, 167, _seq._;
he guessed that sight was not instantaneous, 236, 237

Galle, Dr., 245, 329

Gauss, 299, 300

Gilbert, Dr., 139, 140, 157, 188;
his _De Magnete_, 140, 144

Greeks, their scientific methods, 7

Groombridge's Catalogue, 315

H

Hadley, 185

Halley, 192, 193, 194, 195, 197, 215, 218, 219, 246, 258, 260, 261, 340,
341;
he discovered the _Principia_, 194

Harvey, 144, 149

Haughton, Dr., 321;
his manual on Astronomy, 21, note

Heliometer, described, 311

Helmholtz, 378

Helmont, Van, invented the word "gas," 141

Henderson, 310, 314

Herschel, Alexander, 275, 277, 278, 279

Herschel, Caroline, 275, 276, 279, 286, 345;
her journal quoted, 277, _seq._;
her work with William H. described, 284

Herschel, Sir John, 283, 285, 327, 329

Herschel, William, 185, 234, 235, 244, 249, 274, 275, 280, 281, 282, 284,
288, 289, 29