Part 40

Lumen-hour: defined, 215

Lumens: 60, 94, 215

Lutheran Church, 49

Lyceum Theatre, London, 73

Maeterlinck, Maurice, 9

Magazines, 8

Magdsick, H. H., 303

Magnesia: 84; Nernst's application of, 138

Magnesium, 179, 180

Magnetite arc, 187

Man: distinction between, and animal, 3; artificial light and early, 4; light-sources of primitive, 25

Manganese, 262, 268, 294

Mangin, 188

Mann, 129

Mantles, 95

Manufacturing, 8

Marconi, 68

Marks, 118

Matches: as light-sources, 21; 22, 82

Maxwell, 68

Mazda lamps, 289, 339

Mecca, 40

Mediterranean Sea, 163

Mercury-arc: Way's, 124; 125, 126; quartz, 125, 126; attempts to improve color of, light, 125

Middle Ages, 46, 47, 474

Milton, quoted, 5

Mirror, 19

Mohammedans, 40