rd, 37, 263-5
on vortex motion, 221-2

Kinetic energy, 89
electro, 217

Kirchhoff, 43

Laplace, 317
nebular hypothesis, 317

Larmor, Dr., 22, 44, 56, 63, 93, 163
on electrons, 284
on aetherial physics, 22, 327-9

Lavoisier, 42

Law of gravitation, 24
of inverse squares, 27

Laws of electricity, 184
of light, 145
of heat, 113
of motion, 9, 15, 233

Lead, 88, 333

Lebedew, 32, 76, 153

Le Verrier, 25
discovery of Neptune, 25

Leyden jar, 157

Liebnitz, 223

Light, 75
a mode of motion, 122
corpuscular theory of, 123
undulatory theory of, 123, 136
electro-magnetic theory of, 156
path of a ray of, 144
intensity of, 145
reflection of, 136
refraction of, 135
aberration of, 149
composition of, 139
velocity of, 148
zodiacal, 277
transverse vibration of, 130

Lines of force, electric, 173
magnetic, 201-3

Liquefaction of gases, 47

Liquid air, 47

Liquids, 48

Little Bear, 307
Dog, 307

Lockyer, 109

Lodge, Dr., 219
on aether density, 69
on aether, 284, 289, 328, 332
on electric inertia, 330
on electricity, 64, 69, 284, 285
on force, 17
on gravitation, 283

Lorentz on light, 154

Lyra, 307

MacLaurin, 2, 10, 17

Magnesium, 79

Magnet, 21

Magnets, bar, 199
moving, 211

Magnetic axis, 202
field, 199
lines of force, 200
shells, 205
equator, 202
induction, 199
variation, 208
molecules of, 193
polarity, 194

Magnetism of earth, 207-12
of planets, 211
cause of solar, 211
Ampere's theory of, 193

Mars, 68, 79
a magnet, 196
rotation of, 219
size of, 236
orbital velocity of, 251
satellites of, 178
orbit of, 33

Mass, 27, 53, 187
of earth, 235, 242
of planets, 235, 242
of sun, 190

Matter, elements of, 40
properties of, 42, 50
and motion, 41, 322
conservation of, 42
divisibility of, 44
four states of, 48
aetherial basis of, 48, 333
physical constitution of, 334

Maxwell, J. C., 43, 73, 85, 151, 211
on physical lines of force, 168, 203-5, 288
on aether, 59, 206
on magnetism, 205
on electro-kinetic energy, 180, 217
on aether, 58

Mayer, 84, 86, 114, 118

McCullagh, 75

Mechanical energy, 87

Medium, Descartes on a, 221
Kepler on a, 222

Mercury, 68, 79
a magnet, 196
rotation of, 219
eccentricity of orbit, 33
mass of, 242
orbital velocity of, 251

Meteorites, 95, 118

Meteors, 31, 85, 118