composition of, 250;
covered with an atmosphere of clouds, 253, 254;
density of, 558;
diameter of, 247, 558;
distance from the Earth of, 110, 111;
distance from the Sun of, 246, 558;
habitability of, 257;
heat received from the Sun by, 256;
internal heat of, 252, 256, 515;
lack of permanent features of, 253;
lack of solidity of, 248, 253, 254;
moment of momentum of, 554, 555;
occultation of, 255;
orbit of, 114, 115, 246;
path of, perturbed by the attraction of Saturn, 316;
periodic time of, 558;
a planet, or "wanderer," 111;
red spot in 1878, 253;
revolution of, 246;
rotation of, 201, 202;
satellites of, 247, 249, 257-261, 265, 559;
satellites of, and gravitation, 266;
satellites of, and the Copernican theory, 267;
shadow from satellites of, 257;
shape of, 201, 202, 247, 252;
size of, compared with the Earth, 19, 246, 248,
and other planets, 114;
and the Sun, 114;
storms on, 256;
tides on, 555;
weight of, 248, 250,
and Encke's comet, 350

K

Keeler, Professor, and Saturn's ring, 288

Kempf, Dr., and the Sun's velocity, 484

Kepler, and comets, 360;
and laws of planetary motion, 10;
and meteors, 386;
and the orbit of Mars, 209;
explanation of his laws, 147, 148, 533;
his discovery of the shape of the planetary orbits, 136, 138;
his first planetary law, 138;
lunar crater called after him, 90;
prediction of the transit of Venus and Mercury, 163, 178;
second law, 141;
third law, 142

Kids, the, 414

Kirchhoff, and spectrum analysis, 478

Kirkwood, Professor, and the movements of Saturn's satellites, 296

Klinkerfues, Professor, 390

L

Lagrange, and the theory of planetary perturbation, 320-322;
his assumption of planetary rigidity, 531

L'Aigle meteorites, the, 392

Lalande, and Neptune, 332, 333

Landscapes, lunar, 98

Lane, Mr. J. Homer, 522

Laplace, and the nebular theory, 526;
and the satellites of Jupiter, 266;
and the theory of planetary perturbation, 320

Lassell, Mr., and Saturn's eighth satellite, 296;
discovers Neptune's satellite, 334

Law of gravitation (_see_ Gravitation)

Laws of Planetary Motion (_see_ Planetary Motion)

Lead in the Sun, 50

Ledger, Mr., and Mercury, 163

Leibnitz, lunar mountains named after him, 93

Lemonnier, and Uranus, 312

Leo, and shooting stars, 380, 420

Leonids, attractions of planets on, 386;
breadth of stream of, 387;