Chapter XVII: Science in the Twentieth Century (11)

Sea, animal life in (see Marine Animals);
geological work of, iii, 51-8;
man's invasion of the, v, 182-202
(see also Ocean)

Sea Anemones, xii, 23, 37-8

Sea Bathing, x, 312

Sea Birds, xii, 251-4;
feathers of, 244

Sea Breezes, i, 131, 381

Seacoasts, civilization in relation to, xv, 128, 129 (see Coasts)

Sea Cucumbers, xii, 50

Sea Devils, xii, 150

Sea Elephant, xii, 335

Sea Fans, xii, 37, 43

Sea Fleas, xii, 85

Sea Grapes, xii, 75

Sea Hares, xii, 68

Sea Horses, xii, 163

Sea Island Cotton, v, 269, 270, xiii, 236-7

Sea Level, changes in, iii, 83

Sea Lilies, iii, 259, 268-70, xii, 48-9

Sealing Wax, electrification of, iv, 257-8, 258-9

Sea Lions, xii, 333-4

Seals, xii, 333-4, 335

Seamanship, developed in Scandinavia, xiv, 261-2

Sea Mosses, iii, 259, 270

Sea of Darkness, legend, i, 55

Sea Mouse, xii, 54

Sea Necklaces, xii, 73

Sea Pens, xii, 43

Sea Purses, xii, 148

Searchlights, iv, 352

Searchlight Shells, v, 372

Sears, astronomer, ii, 153, 298

Searles Lake, potash supplies, viii, 279

Sears Roebuck & Company, small power sets, vii, 232

Sea Scorpions, iii, 260, 278

Sea Serpents, ancient, iii, 288

Sea Serpent Stories, origin of, xii, 80, 143

Sea Shells, xii, 71-4

Sea Sickness, cause, xi, 127;
James on phenomena of, x, 242

Sea Slugs, xii, 68

Sea Snakes, xii, 225, 229

Seasons, phenology, i, 254, 255

Sea Swallows, xii, 264

Sea Turtles, xii, 192-3;
catching of, 139-40

Seatworm, x, 200

Sea Urchins, iii, 259, 269 (fig.), 270, xii, 50

Sea Walls, of Galveston, xiv, 303;
wave action on, 301-2

Sea Water, atmospheric carbon absorbed by, i, 14;
density of, iv, 149;
effect on seed, xiii, 346;
gold in, viii, 197, xiv, 295;
organic life in relation to, viii, 355, ix, 174, 175;
radioactive matter in, i, 143;
salts and other dissolved substances, iii, 51-2, viii, 139, 140, 279,
xiv, 295-7;
salts in, gradual accumulation, ix, 175-6

Seaweeds, classification, iii, 251;
flowerless plants, xiii, 13, 43;
great Pacific, 27, 66-7;
habits and character, 72-3;
iodine in ash, viii, 197;
potash from, 279, xiv, 67, 68;
Pre-Cambrian, xiii, 304;
remains in old strata, iii, 20, 250, 251, 252, 256;
reproduction, xiii, 166

Sea Wrack, fertilization, xiii, 151-2

Sebaceous Glands, ix, 313-14, x, 310

Sebum, x, 310

Secchi, Fra Angelo, ii, 17, 114, 115

Secchi Classification (stars) ii, 115-16, 118

Second, unit of time, iv, 70

Secondary, Cyclonic, i, 238, 381

Secondary Cells, iv, 383, vii, 363 (see Storage Batteries)

Secondary Coils, iv, 383;
of transformers, vi, 308

Secondary Currents, vii;
in induction coils, vii, 243

Secondary Rock (see Sedimentary Rock)

Secondary Spectrum, ii, 101, 108

Secretin, x, 325

Secretion, Borelli on, x, 72;
metabolism of, ix, 159

Secular, meaning in astronomy, ii, 74

Secular Parallax, ii, 316-17

Sedentary Habits, food requirements with, ix, 297;
sluggishness from, 223, 251

Sedges, xiii, 187-8;
family, 179, 180;
fertilization, 148;
first appearance, 319;
product and origin, 244;
stems, 182 (fig.)

Sedimentary Rocks, iii, 13, 382, viii, 191, xiv, 18;
folding of, iii, 85, xiv, 32, 36 (see Folding of Rock);
fossils in, iii, 16-17;
jointing of, xiv, 130;
land forms in, 44, 80-99;
marine, 19-20;
oldest, iii, 163, 165, 167;
original horizontal formation, xiv, 36;
weathering of, 79
(see also Strata)

See, on binaries, ii, 377

Seed of Plants, xiii, 59-62;
absent in some plants, 13, 14, 215, 218;
of annuals, 53;
destruction of, xv, 21;
dispersal methods, xiii, 55-9, 338-48;
dispersal by sea currents, xii, 42;
fats from, viii, 246;
germination (see Germination of Seed);
naked and enclosed, xiii, 174-5, 178;
number and increase, xv, 19;
persistence of life in, ix, 16-17;
small-sized, xiii, 344;
storage of food in, 96, ix, 27-8, 278;
survival of, by what determined, xv, 22, 23, 25;
waste of, xiii, 11-12

Seed-bearing Plants, iii, 251

Seed Ferns, iii, 251, 254-5

Seed-habit, beginning of, xiii, 309, 310

Seeding Machines, v, 244

Seed Leaves, xiii, 60-1 (see Cotyledons)

Seedless Plants, xiii, 13, 14
(see also Cryptogams)

Seedlings, destruction of, xv, 21

Seeing Machines, v, 331-2, 334-5

Seihun River, xiv, 185

Seine River, tidal basin, v, 176;
trench of, xiv, 89

Seismographs, iii, 93

Seismology, xiv, 337

Selection, artificial, ix, 327, xvi, 154-5, 157-8;
natural (see Natural Selection)

Selenite, iii, 331

Selenium, sensitiveness to light, v, 332, 334;
symbol and atomic weight, viii, 383

Seleucus, astronomer, ii, 28

Self, "real," x, 302
(see also Personality)

Self-abasement, xi, 55;
in admiration, 147

Self-assertion, xi, 56, 146

Self-Control, xi, 257

Self-encouragement, xi, 278;
in salesmanship, 336-40

Self-excited Dynamos, vi, 187, 191

Self-Feeling, in various sentiments, xi, 146-50

Self-Fertilization of Plants, xiii, 120;
avoidance of, 152-3;
Darwin on, 135;
preventive methods, 120-2, 123, 127-30, 131, 134, 135, 141-2;
as last resort, 135-44

Self-Gratification, impulse of, xv, 185

Self-induction, vii, 375

Self-interest, not the motive of crowds, xi, 330-1

Self-luminous Objects, ix, 105-6

Self-Maintenance, impulse of, xv, 185, 186-204, 273

Self-Perpetuation, impulse of, xv, 185, 273

Self-preservation, emotions of, ix, 153, 165-6, 171-2;
instinct of, x, 9-10, 282-3, xv, 273

Selfridge, Admiral, periscope, v, 200

Self-Sacrifice in plants, xiii, 52-3, 61-2, 117, 151

Self-Starters vi, 238-9, vii, 120, 127, 142-3

Selkirk Mountains, snow mushrooms, i, 116

Semaphores, i, 282

Semicircular Canals, ix, 89-90, 101 (Fig.), x, 126;
in fishes, xii, 137

Semites, rule of fathers among, xv, 367

Semitic Languages, xv, 161-3

Semitic Religion, sun-worship in, ii, 20

Semmelweis, x, 114, 115, 122, 144;
debt of women to, x, 149

Seneca, on comets, ii, 85

Seneca Lake, xiv, 203;
delta in, 211

Senecio, seed dispersal, xiii, 345

Sensation, xi, 62-4;
defined, 67-8;
dependent on motor response, 43, 66, 74-5, 102-3, 110-11, 118-21,
123-4, 202-3;
dependent on sense organs, x, 118;
hallucinatory, 358;
nervous impulse from, xi, 19;
perceptions and, 160-1;
physical effects, 67-8;
physical essentials and cost, 25;
threshold of, 71
(see also Senses)

Sense Organs, at birth, ix, 349-51;
cell structure of, 22;
classes, 86;
condition in attention xi, 228-9;
connections with brain, ix, 142-4, 145-6;
connections with dendrites, xi, 19;
connections with muscles, ix, 19-20, 122, 124-37, 139, 140;
development in embryo, xi, 35;
in amphibians xii, 169;
in fishes, 137-9;
of skin, ix, 314;
part of, in maintaining life, 19, 21, 23, 166-7;
percentage of error, xi, 184-5;
receptive attunements, 62;
sensations dependent on, x, 118;
threshold of sensation, xi, 71;
summation of stimulations, 21-2

Sense Perception, motions of, ix, 82

Senses, contact, ix, 86, 91-5;
distance, 86, 96-121;
hypnosis of, xi, 315;
internal, ix, 86, 87-91;
number and kinds, xi, 63-4, 109;
primary purpose of, ix, 86-7

"Sensible Temperature," i, 318, 381

Sensitive Plant, xiii, 113-14

Sensory Nerve Cells, ix, 125, 126 (fig.);
at birth, 348;
connections of, 129-31, 142

Sensory Neurones, xi, 21;
development in embryo, 34, 35

Sensory Reaction Type, xi, 155, 156-7, 158, 159

Sentiments, xi, 143-51;
in advertising, 345-6

Sepals, xiii, 45, 47

Separately-excited Dynamos, vi, 187, 191

Separate Origin Theory, xv, 69

Separation, energy of, iv, 82

Separators, electromagnetic, vi, 103-4

Sepia, origin of, xii, 79

September Massacres, honesty of crowds, xi, 331

Septicemia, x, 198

Septic Tanks, viii, 328

Sequoias, ancient and present, iii, 256;
Californian, xiv, 374;
climatic record in rings, i, 199-200, xiv, 362;
former distribution, 375

Serbia, Austria's control of, xiv, 306;
Turkish conquest, 243

Serbian Language, xv, 162

Series, chemical, viii, 381

Series Circuits, vii, 364, 375

Series Field of dynamos, vi, 189

Series Wound Motors, vi, 231-4

Serow, xii, 325

Serpentine, iii, 338

Serpents, xii, 211-38;
descent of, 203;
eggs, care of, xv, 275

Serpollet, flash boiler, v, 213

Serpula Tubes, xii, 55

Serums, used in diagnosis, x, 215-16;
use of, in disease prevention, 218, 296-7, xv, 49
(see also Antitoxins)

Serum Sickness, x, 212, 215

Serval, xii, 357

Servant Question, electricity and, vii, 74, 90

Sesheta star goddess, ii, 24

Seven, basic number, xvi, 80;
former supposed virtue of, ix, 115

Seventeen-year Locusts, xii, 112, 113

Severinus, Marcus Aurelius, x, 79

Severn River, tidal basin, v, 177;
tides of, xiv, 293

Seville, Giralda Observatory, xvi, 100

Sewage, composition, disposal, and purification, viii, 324-9;
in water supply sources, 318, 319, xiv, 140-1;
oyster and clam poisoning by, xii, 59;
plant fertilizing by, viii, 327, 343-4

Sewer Gas, harmlessness, i, 326

Sewer Pipes, bamboo stems as, xiii, 183

Sewers, rainfall and, i, 110

Sewing Machines, v, 283, 284-5, 379;
embroidering and lace-making, 285-8;
motor-driven, vii, 84-5

Sex, determination of, ix, 338-40, xvi, 156;
effectiveness of jokes on, xi, 355-6;
hereditary traits, bound up with, ix, 338, 340-1;
in flowers, xiii, 46-7;
in various trees, 191-2;
influence on disease, x, 237;
of twins, ix, 44

Sex Chromosomes, ix, 339;
hereditary traits carried in, 338, 340-1

Sex Determiners, ix, 338-9, x, 234, xvi, 156

Sex Glands, double functions of, x, 347

Sex Relations, among animals, xv, 274-7, 277-8;
among primitive men, 277-8;
varying ideas of morality in, 286

Sexual Feelings, xi, 63, 138, 139

Sexual Impulse in man and animals, xv, 273, 274;
repression of, x, 356

Sexual Reproduction (see Reproduction)

Sexual Selection, xv, 274

Seychelles Islands, coco-de-mer of, xiii, 60, 154

Shad, xii, 154-5;
river habits of, ix, 174-5

Shadbush, leaves of, xiii, 105

Shaddock, origin, xiii, 226

Shadoof, v, 18-19

Shadows, iv, 332-4;
colored, xi, 94-5;
in distance perceptions, 183;
in perception of solidity, ix, 120;
savage fear of, xv, 330

Shaft-sinking, v, 260

Shagreen, xii, 134

Shakespeare, pronunciation changes since, xv, 156

Shale, iii, 13, 382;
petroleum source, viii, 209-10;
schist and gneiss from, iii, 169, 189;
weathering of, 27

Shaler, Nathaniel, on lunar surface, ii, 376

Shallow Water Belt, xiv, 24-5 (see Continental Shelf)

Shamash, sun-god, ii, 20

Shame, Carlyle on, x, 306;
custom and, xv, 254-5

Shape, perception of, ix, 105

Shapers, metal cutting by, v, 47

Shapley, astronomer, ii, 17, 153, 326-7, 330, 337, 338, 339, 340, 356

Sharks, xii, 142-7;
caudal fin in, 133;
evolution, iii, 282, 284;
eyes of, xii, 138;
gill clefts in, 148;
scales of, 134;
sense of smell in, 139

Shark's Teeth, fossils of, xii, 142

Sharps, musical, iv, 208, ix, 100

Shasta Indians, arrows of, xv, 196 (fig.)

Shasta, Mount, iii, 106, 226

Shat-el-Arab, xiv, 185

Shaw, Lieut., aeronaut, i, 285

Shaw, Sir Napier, i, 139-40

Shear, plane and torsional, iv, 158

Shearing Machines, motors used, vi, 234-5

Shearing of Sheep, pneumatic, v, 130

Shears, as levers, v, 23, 46

Shearwaters, xii, 252

Sheep, xii, 324, 326;
anthrax of, Pasteur's work on, x, 140-2;
domestication of, xv, 197;
elastic cord in neck, ix, 59;
horns of, xii, 325, 328

Sheep-cold, i, 363

Sheep-raising, in New Zealand and Australia, xiv, 384

Sheet Lightning, i, 148-9, vii, 205, 213

Sheet Tin, viii, 161

Sheldrakes, xii, 257

Shellac, composition and use, viii, 264

Shell-Animals, origin and development, iii, 20, 264, 265-6, 272, 273-5

Shellfish, xii, 57-80

Shells (animal), calcium carbonate in, viii, 152, 354;
deposits, iii, 53, 54, 235, 257-8, 272;
formation of, xvi, 145;
rocks formed from, iii, 13, viii, 152
(see also Chert, Flint, Limestone)

Shells (artillery), v, 371-2, 373;
explosives for, viii, 260;
triple reports in World War, i, 193

Shell Worms, xii, 54-5

Shelter, man's need of, ix, 308-9

Shenandoah River, longitudinal character, xiv, 154;
piracy of, iii, 38-9

Shenandoah Valley, xiv, 167

Sherrington, Charles, x, 131;
quoted, xi, 12

Shetland Islands, storm waves in, xiv, 300

Shields, xv, 221

Shields River, Montana, xiv, 176

Shields, Tunnel, v, 122-4

Shin, bones of, ix, 68, 70 (fig.)

Shiners, xii, 161, 163

Shinleaf Plants, xiii, 99

Shipbuilding, developed in Scandinavia, xiv, 261

Ships, ancient and modern, xiv, 265;
bottoms, how cleaned, ix, 174, 175;
bow and stern shapes, v, 191-2;
concrete, 194-5;
gyroscopic stabilizing, 341-2;
handling in cyclones, i, 277-8;
Marconi distress system, vii, 284;
materials of hulls, v, 194-5;
measuring of position of, 65-6;
refrigerating systems, 353;
St. Elmo's Fire on, i, 157;
speed and driving power, v, 190-2;
strains, 194, 195;
water and air resistance, 190-2;
wireless directing, vii, 284, 285;
why they float, v, 95
(see also Steamships, Steel Ships)

Ships' Chronometers, v, 65-7

Shirt Tree, xv, 256

Shivering, heat production by, ix, 309-10

Shoals, xiv, 286;
aerial mapping, i, 47;
effect on waves, v, 124

Shoal Water Belt, xiv, 24-5, 46-7 (see Continental Shelf)

Shock, cause and treatment of, ix, 195;
kinetic theory, xi, 59;
low blood pressure in, x, 336

Shoes, mending of, by electricity, iv, 10;
proper and improper, ix, 69-70, x, 306;
working, xi, 279

Sholes, typewriter, v, 312, 380

Shooting-Star Plant, xiii, 203

Shooting Stars, ii, 164, 283-9;
altitude in air, i, 17
(see also Meteors, Meteorites)

Shops, displays and weather, i, 266;
electric wiring, vii, 57

Shore Lines (see Coasts)

Shore-Weed, distribution, xiii, 352

Short-Circuits, defined, vii, 375;
protection against, 35-50

Shortening Agents, viii, 232

Shorthand Typewriter, v, 313

Short Heads, skull index in, xv, 42

Shoulder Blades, ix, 63 (fig.), 66

Shoulder Girdle, ix, 66

Shoulder Joint, ix, 66;
dislocation of, 71

Shovels, most efficient lifts, xi, 362

Showers, curious, i, 355-9, 55

Shrews, xii, 366, 367, 368

Shrimps, class of, xii, 81, 82;
swimming of, ix, 39

Shrubs, garden, planting tables, xiii, 272-89;
hairy covering, 104-5;
in plant classifying, 175;
older than herbs, 319;
roots, 16

Shu, Egyptian god, xvi, 77

Shuman, Frank, solar engine, ii, 169;
sun-power plant, v, 177-8

Shunt Circuits, vii, 364

Shunt-Wound Dynamos, vi, 187-8, 191-2

Shunt-Wound Motors, vi, 229-31, 232

Siam, opium in, xiii, 253;
rivers of, xiv, 196;
viper of, xii, 230

Siberia, animals of, xii, 317, 349, 350, 356;
anti-cyclone of, i, 218;
extinct animals, iii, 16;
low temperatures, i, 209-10;
plains and table lands of, xiv, 217;
rift valleys in, 123;
rivers of, 195

Sibert, Maj.-Gen'l William, x, 187

Sicily, earthquake belt of, xiv, 340;
temporary island near, 319-20

Sickles, evolution, v, 240

Sickness (see Disease)

Sidereal Period, of moon, ii, 196

Siderite, viii, 156

Siemens, Sir William, xvi, 175, 176

Sierra Chica Observatory, ii, 146

Sierra Nevada Mountains, age, iii, 191;
canyons, 225;
cirques, 66;
exfoliation in, 24;
fault scarp of, 89, 225, xiv, 117, 122, 230;
fault valleys in, xiv, 127;
filled lakes of, 212;
former volcanic activity, iii, 226;
geological history, 136, 140-1, 213-14;
glaciers, past and present, xiv, 54-5;
granite core, iii, 112, xiv, 111, 228;
intense folding, 230;
lakes, iii, 143;
metamorphism in, xiv, 234;
Mother Lode gold belt, iii, 366;
power plants, v, 79, vi, 363;
precipitation on opposite sides, xiv, 355;
snowfall, i, 118-19

Sight (sense), iv, 346-7, ix, 104-21, xi, 83-97;
acuteness of, vi, 272-3;
arrival platform for, ix, 146;
center of, xi, 97;
defects of, 112-14;
deficiency, to what due, iv, 322;
development in infants, ix, 350, 351, xi, 40;
direction perception by, ix, 118, 120;
distance and depth perception by, 118-20;
illusions of, iv, 323, 326-9;
in fishes, xii, 138-9;
nerve of, xi, 29-30;
space perception by, 163, 169-70, 171-2, 173, 174-83;
touch and, ix, 92;
walking reflex from, ix, 158

Signal Fires, xv, 165-6

Signals, distress, wireless, vii, 284;
storm, i, 282-8

Signal Service, weather service called, i, 216

Signal Systems, of railroads, vii, 355-9

Signatures, magazine sections, v, 306-7

Sign Languages, xv, 148-51

Sign Lighting, vi, 280, vii, 339-48;
colors in, iv, 51;
psychology of, xi, 344, 345, 346

Silence, from interferences of sound, iv, 218, 219, 220-2;
horrors of world of, 51;
zones of, i, 189-92, 381

Silica, viii, 90; in earth's crust, 193;
in iron ore, iii, 356;
in organic compounds, ii, 243;
petrifying material, iii, 127;
residue of primary rock, viii, 195

Silicates, identification, viii, 201;
in earth's crust, 90, 193, 194, 198, 200-1;
in glass making, 281;
preparation of, 117;
specific gravities, 202

Silicles, xiii, 197

Silicon, viii, 19, 90;
atomic weight and symbol, 383;
compounds, 90;
in body tissues, 354;
in earth's crust, iii, 308, viii, 19, 129, 192;
in wireless detectors, vii, 269;
metallic, 300-1;
plant needs of, viii, 337, 341

Silicon Carbide, vii, 310 (see Carborundum)

Silicon Dioxide, viii, 90

Silk, as clothing material, ix, 311-12, x, 308, 309;
chemistry and manufacture, viii, 256;
dyes for, 269;
electrical conductivity, iv, 259;
electrification of, 257, 258, 259;
vegetable, viii, 255-6

Silkworm Moths, xii, 119

Silkworms, Pasteur's work on diseases of, x, 140

Sills (geological), xiv, 108-10;
columns in, 130; illustration, 107

Sill Tunnel, corrasion in, iii, 29

Silurian Period, iii, 20, 191-4, 382;
animals and plants of, 252, 268, 274, 278, 282, 284;
limestones of, xii, 49;
species of, xv, 71

Silver, iii, 338;
affinity strength, viii, 128;
atomic weight and symbol, 383;
atomic weight determination, 308-9;
contraction on solidifying, iv, 150;
electrical conductivity, 283, vi, 80;
electric positiveness, 59;
extraction from ores, viii, 140, 170, 269, 270, 271-2;
fusibility, 384;
heat conductor, iv, 179;
in heavy metal group, viii, 126-7;
melting point and requirements, iv, 162;
metallurgy of, xvi, 176;
occurrence and uses, viii, 170-3, 198;
"parting" from gold, 272;
production, iii, 367-8;
recovered in copper refining, vii, 319, 320, viii, 272;
refining of, vii, 320;
specific gravity, viii, 384;
sterling, 171;
tarnishing of, 13, 77;
tests for, 286, 288

Silver Bromide, in photography, viii, 172

Silver Chloride, analysis, viii, 292;
in photography, 173

Silver Compounds, in photography, viii, 171-3

Silver Nitrate, uses, viii, 72, 146, 290

Silver-Plating, vii, 318-19, viii, 284

Silver Suboxide, viii, 97

Silver Sulphide, viii, 13, 170-1

Silver Thaw, i, 108, 381

Similarity, association by, xi, 197

Simon, Gustav, x, 131

Simoons, i, 134, 381

Simple Mechanical Powers, iv, 25

Simplon Tunnel, heat encountered in building of, iii, 121, xiv, 14;
length and altitude, 240, 241

Simpson, Dr. G. C., i, 93, 150

Simpson, Sir James, xvi, 185

Sims, Marion, x, 122, xvi, 186

Sin, disease as result of, x, 380

Sine Curves (electricity), vi, 201

Singers, range of, ix, 99;
vocal cords of, 83

Singer Sewing Machine, v, 285

Singing, development of art of, xv, 296, 312-15, 325;
of teakettle, iv, 167

Single-celled Animals, iii, 265 (see Unicellular Animals)

Single-celled Plants, xiii, 166, 167

Single-fluid Theory, vi, 288-93

Single-Phase, defined, vi, 201-3

Single-Phase Currents, advantages and disadvantages, vii, 196

Single-Phase Induction Motors, vi, 241, 250

Single Rail Cars, v, 342-3

Single-thread Sewing Machines, v, 285

Sink Hole Lakes, iii, 157

Sink Holes, iii, 127 (fig.), 128

Siphon, atmospheric pressure in, i, 25;
in ancient Egypt, xvi, 68

Siphonophores, xii, 37

Siren Whistle, iv, 205

Sirian Stars, ii, 115, 117;
distance and brightness, 353;
in galaxy, 122

Sirius, angular diameter, ii, 151;
binary system, 334;
brightness, 263, 295, 316;
color, 115, 296, 297;
companion of, 109;
composition, 115;
displacement in spectrum lines, 119;
distance and parallax, 315, 319;
distance increasing, 119-20;
in moving cluster system, 343;
magnitude, motion and type, 319;
origin of name, 302

Sirocco Winds, i, 134, 381

Sisal, ropes from, xiii, 10;
source of, 188, 240-1

Sitatungas, xii, 327

Sitka, climate of, xiv, 345

Sitka Spruce, in Pacific forests, 374

Sitting, right posture, importance of, ix, 57
(see also Sedentary Habits)

Size, effect on attention, xi, 344;
perception of, ix, 105;
physiological actions dependent on, 296, 347

Skaptar Jokull, i, 59

Skaters (bugs), xii, 114

Skates (fish), eggs of, xii, 140;
gill clefts in, 148

Skeletal Muscle, ix, 75-84;
breathing controlled by, 256-7;
contraction and relaxation, of, 164;
nerve connections of, 160, 162;
voluntary control of, 163
(see also Muscles)

Skeleton, of vertebrates, xii, 132;
weight of, iv, 13;
compared with apes, xv, 59;
bones of, ix, 59-71;
cartilage beginnings, 58;
connective tissue, 13, 71-2

Skeptics, Greek, xvi, 85

Skill, of artisans, past and present, v, 42, 46;
fineness of discrimination in, xi, 125-6;
origin in response processes, 45;
will in relation to, 263-4
(see also Proficiency)

Skim Milk, viii, 363

Skin, blood vessels of, how controlled, ix, 161, 163, 215, 216, 217;
body heat regulation through, 310-12, 314-16;
chilling of, effects, ix, 323;
cold and warmth spots, 93;
colors in different races and latitudes, xv, 36-7;
cuticle of, ix, 312-13;
development in black and white races, xv, 49-50;
dry feeling, i, 322;
effects of cold and wet on, x, 239;
electric insulator, vii, 247;
excretions of, ix, 314, x, 310-311;
exercise effects on, 303;
fear effects, xi, 131, 132;
flushing and paling of, ix, 161, 162, 163, 165, 215;
functions, 312-14, x, 310;
germ infection through, 198, 201-2;
growth of, ix, 47-8, 287, 312-13;
hyperemia in sleep, xi, 284, 289;
of Nordics and Iberians, xvi, 48, 49;
oiling of, in hot and cold climates, x, 311;
pain organs in, ix, 314;
pores of, 322;
protective structure, x, 201;
sebaceous glands, ix, 313-14, x, 310;
sense organs in, ix, 314 (see Contact senses);
structure and sensations, xi, 109-15, 164-6, 184;
sunlight effects, vii, 249;
suppressed emotion effects xi, 141-2;
temperature, i, 318;
temperature sensations in, ix, 93-4, 319-20;
touch sense of, 92

"Skin Friction," v, 191, 192

Skin Grafting, x, 183, 189

Skin Pain, xi, 117

Skins, as clothing, xv, 256, 257;
canoes and rafts of, 264;
use in ancient Egypt, xvi, 73

Skipping Silverfish, xii, 104

Skoda, Josef, x, 113, 115

Skolai Creek, Alaska, iii, 217

Skuas, xii, 264

Skull, Skulls, bones of, ix, 61-3;
bones in infants, 345;
measurement and classification of, xv, 42;
of apes and men compared, 42-3, 62;
of European races, xvi, 49, 50;
of primitive men, xv, 91, 93;
of various races, 41-3;
use for drinking vessels, 248

Skullcap, flowers, xiii, 201, 205

Skull Capacity, xv, 40;
in various men and races, 40-1;
of apes and men, 89, iii, 302-3;
of primitive man, 304, xv, 89, 94-5

Skull Index, xv, 42

Skunk Cabbage, xiii, 188, 350

Skunk, absence of fear, xi, 136;
luminous species, i, 347;
protective means, xv, 18, xii, 347, 348

Sky, colors, explanation, i, 164, 165-6;
in art, 105;
man's invasion of, v, 219-38;
shadows of mountains in, i, 169-70

Skyscrapers, as lightning protection, vii, 219;
in earthquakes, xiv, 343;
wind-thrust on, v, 194

Slag, viii, 157-8;
phosphate from, 280, 345

Slasher (weaving), v, 280

Slate, iii, 382;
metamorphic rock, xiv, 19;
origin and occurrence, iii, 372;
quarries in N.Y., 189

Slaughterhouse Waste, as fertilizer, viii, 280, 343

Slavery, social results of, xv, 376, 378-9

Slavo-Lettic Tongues, xv, 162

Slavonian Language, xv, 162

Slavs, in Alpine group, xvi, 49;
north and south, xv, 137

Sledges, in transportation, v, 214-15

Sleep, xi, 281-91;
autosuggestion and, 306;
causes and factors of, ix, 218-19;
hot baths and, 322;
heart rest in, 210;
life during, ix, 11-12, 17;
metabolism during, 282-3, x, 271;
mind activity in, xvi, 19;
nature and functions, xi, 281-91;
periodic breathing in, x, 340;
primitive conceptions of, xv, 328, 329, 332;
retardation of impulses in, xi, 20;
skin during, 110;
tea and, xiii, 227;
time spent in, ix, 80

Sleeping, of plants, xiii, 88-9, 113;
outdoor, x, 240

Sleeping Sickness, immunity and susceptibility to, xv, 49, 50, 51 (see
African, European Sleeping Sickness)

Sleep-Walkers, xi, 286-7

Sleet, i, 107-8, 381;
glaze called, 373;
ice rain, 375

Sliding Elasticity, iv, 157-8

Sliding Friction, v, 203, 204, 207, 214-15

Slings, xv, 219-20

Slip Rings, of alternators, vi, 159, 177, 196-7

Slipher, astronomer, ii, 131, 147, 337, 363

Slivers, cotton, v, 272, 274

Slogans, effectiveness, xi, 332

Slot Machine, Hero's, xvi, 93

Sloths, xii, 282, 283

Slow Sand Filters, viii, 319-20

Slowworms, xii, 206

Slugs, xii, 69-70

Slums, infant mortality in, ix, 352

Smallpox, African superstition of, x, 285-6;
consumption from, 292;
early inoculation for, 100-1, 207;
eruption on uncovered surfaces, 254;
European epidemic of, 59-60;
first described by Rhazes, 32;
germ of, 200;
immunity to, 207;
prevention of, xv, 49;
racial susceptibility to, 50, 51;
vaccination discovery, x, 100-3, 207-8;
vaccination success, 217

Smeaton, on Watt's engine, v, 44

Smell (Sense), ix, 96-8, xi, 69, 77-82;
direction perception by, ix, 117, 120;
distance perception by, 121;
food-judging by, 95;
in fishes, xii, 139;
in insects, 101;
in infants, ix, 350-1;
nerve of, xi, 29-30;
photisms of, 222;
sense of, location, x, 341

Smellie, William, x, 104

Smelling, motions of, ix, 82-3

Smelting, v, 315-16, 317-18;
dependent on oxygen, i, 24;
history of processes, xvi, 174, 175, 176;
precipitation treaters in, vii, 348-51;
smoke from, 345, 346, 347

Smelts, xii, 154, 159

Smilax, leaves, xiii, 183 (fig.)

Smilax Family, xiii, 188

Smiling, psychology of, xi, 357

Smith, Prof. J. Warren, i, 246, 248, 253

Smith, William, geological work, iii, 15, 18, xvi, 126, 168-9

Smith River, Montana, xiv, 176

Smithsonian Astrophysical Observatory, ii, 186

Smithsonian Institution, i, weather observations, i, 215-16

Smoke, cause and prevention, vii, 343-5, viii, 45-6;
cloud and fog nucleus, i, 91, 94;
electrical precipitation, vi, 164, vii, 216, 301-2, 343, 346-51;
evils and war against, i, 63-5, viii, 304;
from fires, in air, i, 56-7;
from gunpowder, viii, 145;
in air, clearing of, ix, 269;
moor, i, 56;
nuisance and waste, vii, 345-6

Smokeless Powder, viii, 145, 260-1;
introduction, xvi, 163

Smoke Screens, phosphorus, viii, 87

Smoking, of foods, viii, 372

Smoking of Tobacco, xiii, 256;
cancer from, x, 120;
heartburn from, ix, 232

Smooth Muscle, ix, 74, 84-5;
adrenalin effects on, 171;
chemical control of, 167-9, 170, 336;
emotional control, 163-7, 168;
habit in operation of, 251;
nerve connection and control, 159-69;
occurrence in body, 160-2;
reflex control, 163

Smoothness, sensation of, xi, 128

Smuggled Goods, X-ray search for, vii, 256-7

Smyth, Piazza, ii, 141

Snails, iii, 260, 272, 272-3, xii, 68-71;
deep sea, 23;
flower fertilizers, xiii, 123, 144, 153;
in lakes, xiv, 211-12;
winged, xii, 19

Snakebird, xii, 253

Snake Hill, N. J., xiv, 110

Snake River, xiv, 174-5;
gorge of, xiv, 166

Snake River Valley, lavas of, iii, 228

Snakes, xii, 182, 211-38;
absence of fear, xi, 136;
ancient, iii, 295;
ancient, xii, 210;
egg-teeth of, xii, 205;
embryological resemblance, xv, 54;
in oceanic islands, xiv, 278;
poison of, xv, 18

Snapdragon, flowers of, xiii, 190, 201

Sneers, origin, xi, 133

Sneezing, in infants, ix, 349;
nervous mechanism, xi, 19, 20;
reflex action, ix, 135, 258

Snell, Willebrord, ii, 58

Sniffing, effect of, xi, 80;
purpose of, ix, 82-3, 96

Snipes, xii, 262-3

Snow, i, 114-17, 381;
forests and, xiv, 378;
freezing mixtures with, iv, 175;
from cloudless sky, i, 119;
glaciers and, iii, 59-60;
railroad problem, i, 267;
regelation of, iv, 166;
removal problem, i, 117;
water supply from, i, 118;
winter wheat and, 253

Snow Bins, i, 118, 381

Snow Clouds, i, 101, 102

Snow Crystals, i, 115-16

Snowdrops, flowers, xiii, 120

Snow-eater Winds, i, 133, 369

Snowfall, glaciers in relation to, xiv, 54-5;
heaviest in U. S., i, 118-19;
measurement, 79-80, 118, xiv, 351
(see also Precipitation)

Snowfall Charts, i, 206

Snowflakes, i, 115;
clouds of, 92-3, 103;
fogs of, 95

Snow Fleas, xii, 104

Snow Line, iii, 59;
in tropics and arctic, xv, 72-3;
on mountains, iv, 183-4

Snowstorms, St. Elmo's Fire in, i, 157, 158

Snow Surveys, i, 118, 382

Snubbing Posts, friction on ropes on, iv, 94

Soap, chemistry of, viii, 141-3, 221;
hard water effects, viii, 143, 152, 322, xiv, 147;
use of, in bathing, ix, 313, 314, x, 311

Soap Bubbles, iridescence of, xii, 245

Soap Films, colors of, iv, 377, xii, 245

Soapstone, iii, 339-40

Sobieski, John, xiv, 308-9

Sobrero, nitroglycerine, xvi, 163

Social Classes, rise of, xv, 375-8

Social Evolution, xv, 29-31

Social Institutions, crowd psychology in, xi, 333;
development of, xv, 29-31, 383-4

Socialism, theories of, xv, 377-8

Social Workers, in treatment of disease, x, 383

Society, dominant impulses in, xv, 185;
habit and stability of, xi, 255-6;
language the product of, xv, 142

Sociology, concrete science, xvi, 42;
least positive science, x, 368;
medicine and, 369

Socrates, killed by hemlock, xiii, 250;
on essential forms, xvi, 87

Soda, deposits of, viii, 275

Soda Ash, viii, 135

Soda Lakes, xiv, 206, 212

Soda Pulp, v, 294

Sodium, affinity intensity, viii, 128;
affinity for chlorine, 120;
alkali metal, 132;
atomic weight and symbol, 383;
electrolytic production, vii, 320-1, viii, 284;
extraction by electrolysis, 271;
flame color, 134, 301;
fusibility, 384;
in body tissues, 354;
in earth's crust, iii, 308, viii, 19, 129, 148, 192, 195;
metallic nature, 17, 127, 181;
plant needs of, 337, 341;
properties, 133-4;
source of industrial, 275;
specific gravity, 384;
spectrum of, iv, 362, viii, 301;
test for, 287, 289

Sodium Acetate, electrolysis of, viii, 266

Sodium Bicarbonate, viii, 136

Sodium Borate, viii, 141 (see Borax)

Sodium Carbonate, viii, 116;
manufacture of, 276-8;
occurrence in nature, 189, 197;
uses, 135, 146

Sodium Chloride, viii, 138-40;
electrolysis of, 124-5;
ionization in solution, 123, 301;
in urine, x, 343;
pure, xiv, 296;
stability of, viii, 120
(see also Common Salt)

Sodium Compounds, viii, 134-43;
flame color, 301;
in sea, 138, 196, 279;
replacing potassium, 133-4, 144;
uses, 146

Sodium Cyanide, viii, 141

Sodium Feldspar, viii, 90

Sodium Hydrogen Carbonate, viii, 135-6

Sodium Hydrogen Sulphate, viii, 83, 116, 137

Sodium Hydroxide, viii, 134-5;
normal solution, 119;
preparation of, 276, 278, 284;
uses, 135, 141, 142, 221, 255

Sodium Hypochlorite, as antiseptic, x, 146, 181;
preparation, viii, 284

Sodium Iodide, solubility, viii, 112

Sodium Light, colors in, iv, 365

Sodium Nitrate, viii, 137-8;
Chilean deposits, 64, 72, 197, 280

Sodium Nitrite, viii, 141

Sodium Peroxide, viii, 134

Sodium Phosphate, viii, 89, 141

Sodium Silicate, viii, 141

Sodium Stearate, viii, 143, 221

Sodium Sulphate, viii, 83, 116, 137;
electrolysis of, 125

Sodium Sulphite, viii, 117, 140, 146, 372

Sodium Thiosulphate, viii, 140-1, 172

Soffioni, steam jets, v, 179

Soft Coal, combustion, viii, 45;
composition, 252;
conversion into coke, 46, 252;
distillation and products, 252-4;
origin, xiii, 10

Soft Foods, for children, remarks on, x, 314, 315

Softness, sensation of, xi, 128

Soft Soap, making of, viii, 142

Soil, iii, 382;
acid conditions and correction, viii, 346-7;
air in, xiii, 92;
alluvial, xiv, 70-1;
bacteria in, xiii, 98;
clay in, iii, 27-8, xiv, 137;
conservation necessity, 64;
constituents necessary to plants, viii, 341-6, xiv, 64-5, 66-8;
depths of, iii, 26, xiv, 64;
enrichment by nitrogen plants, xiii, 98;
fertilization by lightning, i, 153;
forest protection of, xiv, 379;
formation and nature, iii, 26-8, 32 (illus.), viii, 191, 195, 338-41,
347, xiv, 63-4, 68-9;
glacial, iii, 67, xiv, 69-70;
holding of, by plant roots, xiii, 19;
liming of, viii, 150, 346-7;
loess (see Loess);
of arid regions, xiii, 381, xiv, 68-9;
rainfall effects on constituents, 69;
residual, iii, 26-7, xiv, 68;
restoration of, viii, 341-6, 347, xiv, 66-8, 69
(see also Fertilizers);
sewage application to, viii, 327;
traveled, xiv, 63, 69-75;
vegetation determined by, xiii, 382, xiv, 363-4;
volcanic, 69, 329
(see also Lava Soils);
wind carrying of, i, 53-4, iii, 71, 73-4, xiv, 71-5

Soil Water, absorption by plants, xiii, 91-3;
erosive depths, xvi, 173;
plant materials in, ix, 26, 29;
rise of, viii, 37
(see also Ground Water)

Solar Apex, ii, 305

Solar Constant, iv, 194

Solar Day, iv, 16

Solar Eclipses, ii, 209-18;
corona seen only in, 219;
death of Domitian announced, 221;
difficulty of observing, 219;
Einstein theory tested by, 81-2;
first accurate prediction, 27;
necessary interval between, ii, 224;
Hally's observations, 87;
Hipparchus's discoveries, 32;
prominences observed in, 179, 180;
records of, in ancient China, 21-2;
restricted areas, 207

Solar Engines, ii, 169-70

Solar Spectrum, ii, 111-12, 114, iv, 358-9, 362, 365-7;
lines, how produced, ii, 184;
photography, 128

Solar Stars, ii, 115;
distance, 353;
distribution, 122, 354;
planetary systems, 252

Solar System, bodies and motions, ii, 162-4;
brief description, iii, 158-9;
identity with atomic, vi, 115;
motions accounted for by Newton, ii, 67, 73;
movement toward Hercules, xvi, 124-5;
movement toward Lyra, ii, 122, 137, 305-6;
position in universe, 353-4;
sun as center (see Heliocentric System);
theories of formation, 366-81, iii, 159-63;
unit of measurements, ii, 315

Solar Tides, xiv, 292

Solder, tin and lead in, viii, 161-2, iv, 161-2

Soldering, alloys used for, iv, 161-2

Soldier Beetles, rains of larvæ, i, 356

Soldiers, asleep on march, xi, 286-7;
crowd psychology in battle, 326-7;
crossing of bridges by bodies of, iv, 225;
fatigue relieved by music, x, 247;
lack of choice in, xi, 260-1;
sense of pain in, 119-20;
shoes of, ix, 69

Solenoid, iv, 286-7, vii, 375

Solfatara, volcano, v, 180

Solidification, expansion on, iv, 149, 150-1, 163;
heat of, 160, 161, 188;
suspended, viii, 113, 304-5

Solidism, doctrine of, x, 25-6, 28

Solidity, perception of, ix, 119-20, xi, 173-83

Solids, chemical properties, viii, 297-301;
distinguished by pressure, iv, 22-3;
elasticity of, 156;
expansion coefficient of, 145;
heat conduction by, 176-7;
heat effects on, 144, 152, viii, 25;
melting of (see Melting);
molecules in, iii, 309, iv, 22, 131, 152, 363, viii, 24;
solutions in water, 112-13;
sound velocity in, iv, 198;
spectra of incandescent, ii, 112, iv, 360, 363;
vibration of, 215

Solitaire (bird), xii, 269

Solomon, wives of, xv, 289

Solomon's Seal, rootstalk, xiii, 22 (fig.)

Solstices, observed in ancient times, ii, 25-6

Solute, defined, viii, 382

Solutions, viii, 111;
boiling point and freezing point, 299-30;
chemical reactions in, 37;
colloidal, 314-16;
heat and cold production by, iv, 175;
ionization of, viii, 119-25;
molar, 118-19, 379;
molecular action in, 113, 311;
normal, 119, 379-80;
of gases, liquids and solids in water, 111-13;
osmotic pressure in, 113, 311, xvi, 164;
overheated, viii, 304;
properties of, summarized, 311-12;
specific gravity of, 313;
vapor pressure of, 305

Solutrian Implements, xv, 100, 105, 109

Solvay Process, viii, 276, 277-8

Solvent Action, of water, viii, 111-12;
heat and, 112

Solvents, esters as, viii, 221;
water, alcohol and ether, 217

Somaliland, antelopes of, xii, 327

Somme River, changes in, xiv, 184

Somnambulism, xi, 286-7

Song Birds, xii, 268-9

Songs, primitive, xv, 312-13, 314, 319-21

Sonic Wave Transmission, v, 108

Sonnblick, St. Elmo's Fire, i, 157, 158

Sonora Earthquake, xiv, 334

Soot, i, 52;
deposits, 64, 65;
formation of, viii, 45

Sophists, Greek, xvi, 87

Soranus of Ephesus, x, 26

Soreness, muscle, ix, 80-1

Sore Throat, cause, x, 253;
from colds, 253;
from infection of tonsils, ix, 187

Sorghum Molasses, viii, 243

Sori, of plants, xiii, 64, 155

Souder, Wilmer H., iv, 237

Soul, and body (Hindoo belief), ix, 11-12, 17;
meaning of, xi, 382;
primitive conceptions of, xv, 328-32;
source of vital movement, (Stahl), x, 84;
Thales on universal, xvi, 76;
universal belief in, 44

Soule, Samuel W., v, 312

Sound, Sounds, analysis and synthesis of, iv, 52, 233-4;
atmospheric effects, i, 187;
audibility, distances and variations in, 187-92;
audibility in rain, 187;
audibility (vibration limits), iv, 204;
colored hearing, xi, 222;
dense atmosphere effects on, iv, 31-2;
distance, how estimated, i, 187;
emotions stirred by different kinds, iv, 51-2;
intensity and loudness, 211-12;
interference of, 218-22;
kinds and qualities, xi, 104-8;
motor response, 103;
"musician" of physics, iv, 50;
perception of, by ear, 203-4, 211-12, ix, 99, 100, 103;
perception of direction and distances by, 117, 121, xi, 167-9;
pitch of, (see Pitch);
production, iv, 195-7, ix, 98;
quality of, iv, 232-5;
resonance, 226-32;
shadows, 236;
simple and compound, 213-17;
transmission, i, 186, iv, 195-201, ix, 98-9;
transmission by water, v, 107, 108;
velocity, i, 186-7, iv, 198-9, 200, 201, vii, 210;
wave theory of, iv, 52;
wind effects on, 210-11
(see also Acoustics)

Sounding Balloons, i, 20-1, 382;
heights reached, 22

Soundings, ocean, xiv, 23-4, 284

Sound-ranging, i, 313;
in World War, 201-2

Sound Waves, diffraction of, iv, 52, 236-7;
Doppler's principle, ii, 119, iv, 209-10;
effect on ear, ix, 99, 100, xi, 99-101;
energy, on what dependent, iv, 211;
formation and transmission, 196-201;
frequency and length, 204, 236;
from Krakatoa eruption, i, 188, xiv, 324;
interferences of, iv, 218-19, vii, 279;
interferences in thunder, i, 193;
machine to respond to, v, 331;
mechanical reproduction of, iv, 240;
number, amplitude, and forms, xi, 104-5;
passage through orifices, iv, 236;
photographic records of, 52, 233-4, 237;
power transmission by, v, 107-8;
reflection and refraction of, iv, 236-40;
simple and complex, 213-17;
transmission, i, 186, iv, 196-201, ix, 98-9;
visible, (flashing arcs) i, 194, 372

Soups, value of, at meals, ix, 241, x, 320

Sour, taste of, ix, 95, xi, 70, 71, 72

Sour Disposition, xi, 55

Souring, lactic acid in, viii, 223

Sourland Mountains, xiv, 111-12

Sour Milk, longevity and, xiii, 172

Soursops, origin, xiii, 226

South Africa, ancient reptiles of, xii, 184;
animals of, 281, 304, 327-8, 345, 348, 360;
bushmen of (see Bushmen);
climate of, xiv, 224;
cobras of, xii, 226, 227;
diamond mines, iii, 328;
duet whirlwinds, i, 60;
glacial and coal deposits, iii, 203, 204;
gold production, 365, 367;
kopjes of, xiv, 82;
no weather maps, i, 230;
rodents of, xii, 289, 290;
spurges, xiii, 28-9;
stock-raising in, xiv, 384

South Aldabra, tortoise of, xii, 191

South America, animals (herbivora), xii, 275, 276, 282, 283-4, 289, 306,
313;
animals (carnivora), 342, 360-2, 363, 364;
antiquity of, 282;
birds of, 241, 251, 256, 266;
climate on east and west coasts, xiv, 305;
coasts iii, 57, xiv, 25-6, 247-8, 250, 251;
coasts, coral reefs on, xii, 40;
coffee in, xiii, 232;
drainage systems, xiv, 190;
fish of, xii, 159-60, 166;
former connection with Antarctica, xiv, 290;
former submergence, iii, 216;
indigenous plants, xiv, 382;
meteorological backwardness, i, 218, 230;
monkeys of, xii, 377;
plains of, xiv, 218
(see also Pampas);
plateaus of, 222;
potato in, xiii, 218;
reptiles, xii, 198, 208;
river connections, xiv, 187;
"scrub" vegetation of, 379;
snakes of, xii, 213, 215-16, 221;
temperate forests of, xiv, 371, 382;
tobacco used by natives, xiii, 256;
west coast harbors, xiv, 265

South American Indian, acclimatization of, xiv, 356;
blow gun of, xv, 216, 217 (fig.);
foot-plow of, 236 (fig.);
long bow of, 213 (fig.);
weapons of, 216, 219

South Atlantic Ocean, temperature of, xiv, 297

South Carolina, tin production, iii, 368

South Dakota, bad lands of, xiv, 81 (see Bad Lands);
high temperature, i, 209;
loess deposits, xiv, 72;
"Sunshine State," i, 86;
tin production, iii, 368

Southern Cross (stone), xv, 103

Southern Forest, (U. S.), xiv, 372-3

Southern Hemisphere, climates insular, xiv, 346;
deflection of motion in, i, 125, xiv, 348;
land in, 20;
temperate forests of, 371, 382;
tides in, 292;
winds of, i, 125, 127-8, xiv, 345-6, 348

South Pole, rain at,
(see also Antarctica) i, 109

South Sea Islanders, xv, 9;
chiefs, how chosen, 364;
ideas of morality, 254;
plaited mats of, 243;
writing venerated by, 164;
words derived from, 161

South Sea Islands, atolls of, xii, 41;
snakes absent from, 217

Sowerby, James, xvi, 170

Spa, Belgium, xiv, 145

Space, absolute and relative, ii, 80, iv, 16-17;
æther of (see Æther);
heat transmission through, iv, 180-4;
infinity of, xi, 191, 196;
interplanetary, air absent, i, 186;
perception of, xi, 162-91;
primary concept, iv, 14, 15;
relativity of, xvi, 196-8;
temperature of outer, vi, 270;
time compared with, xi, 192

Spadix, of arums, xiii, 188

Spain, Arab astronomy in, ii, 38;
buffaloes in, xii, 329;
callina, i, 96;
cattle of, xii, 330;
coast formations, iii, 57, xiv, 46-7, 249, 257;
conquests in America, 310;
Cro-Magnons in, xv, 102;
desiccation of, xiv, 379;
esparto grass, v, 292;
formerly peninsula of Africa, xiv, 291;
lynx of, xii, 365;
metal production, iii, 360, 362, 370, xiv, 237-8;
Moorish science, xvi, 100, 106;
potash deposits, xiv, 68, 209;
Pyrenees Mts., as protection of, 239-40;
rainfall of, 358;
solar eclipses, ii, 215-16;
toads of, xii, 176

Spallanzani, Lazaro, x, 88, 139, xv, 114

Spalling, of stones, iii, 24

Spanish-American War, searchlights at Santiago, iv, 352;
typhoid fever in, x, 286;
weather service in, i, 309

Spanish Armada, xiv, 280;
weather importance, i, 307

Spanish Bayonet, xiii, 183

Spanish Fly, x, 111

Spanish Language, descent from Latin, xv, 160, 162

Spare Diet, remarks on, xi, 370

Spark Gaps, in wireless installations, vii, 263, 264, 271-2, 287

Sparking, of electric machines, 375;
potential tables, 383

Sparrows, increase in U. S., xv, 21

Spathe, of arums, xiii, 188

Spawn, of mushrooms, xiii, 164

Speaking Trumpets, iv, 239-40

Spear-throwers, xv, 212 (fig.), 213

Spears, xv, 208-10

Specialization, in civilization, xv, 131-2, 203

Specializing, in science, x, 43

Species, xii, 28, xiii, 170, 329-30;
chromosome numbers in different, ix, 46;
climate effects, on, xvi, 141;
continuity dependent on heredity, xiii, 326;
crossing of (plants), 147;
distribution studies, xvi, 140;
establishment of new, 158;
evolution of, iii, 18, 260-1;
extinction of, 261 (6), 293, xiii, 323;
geological epochs determined by iii, 19;
number in relation to latitude, xiv, 366;
number of plant, xiii, 323;
origin, Darwinian theory, x, 135, xvi, 150-2
(see also Mutation, Variation, Natural Selection);
permanence theory, xvi, 150;
types and, xiii, 356

Specific, technical meaning, iv, 109, 383

Specific Density, iv, 111, 112, 113

Specific Diseases, x, 196

Specific Gravity, iv, 109, viii, 381;
atomic weight and, 313;
discovery by Archimedes, xvi, 89;
methods of determining, iv, 111-13;
mineral identification by, iii, 321-41, viii, 202-3, 313;
of earth, xiv, 11;
of metals (table), viii, 384;
of solutions, 296, 813;
of various substances, iv, 109-10
(see also Density)

Specific Heat, iv, 109, 155-6, viii, 308-9, 382;
of water, 37

Specific Nerve Energy, doctrine of, x, 118

Specifics, medicinal, x, 49-50, 75

Specter of Brocken, i, 184-5, 382

Spectral Types (stars), ii, 115-18, 307-10;
absolute magnitudes and, 317;
binary periods and, 310, 334;
of star clusters, 343-4;
of star streams, 347, 348;
planetary systems and, 252;
solar apex and, 305-6;
speed of, 153

Spectrobolometer, ii, 128, 186

Spectrographs, at Mt. Wilson, ii, 154-5

Spectroheliograph, ii, 129, 183;
in work on sun, 176, 179;
of Mt. Wilson, 148, 154

Spectroscope, ii, 111, viii, 301;
astronomical applications, ii, 17-18, 112-24, 181;
chemical analysis by, viii, 301-2

Spectroscopic Binaries, ii, 122-4

Spectroscopic Parallaxes, ii, 153

Spectrum, Spectra, colors and lines of, ii, 111-12, 113, iv, 358-63,
365-7;
displacement of lines, ii, 119, 120, 121;
displacement of lines to test Einstein theory, 82;
intensity of lines, 124;
interceptions by atmospheric ozone, i, 16;
of airlight, ii, 181;
of aurora, i, 161;
of alkali metals, viii, 133, 147, 301;
of chemical elements, 183, 301-2;
of nebulæ, ii, 357, 359;
of new stars, 332-333;
of stars, 115-18, 119, 123;
of suns' corona, 211, 212, 223, 225;
of sun-spots, 177;
of vapors in magnetic field, 178;
of variable stars, 325, 326, 329;
used in measuring star distances, 153-4, 318;
X-ray, viii, 183, 309
(see also Solar Spectrum)

Spectrum Analysis, ii, 113-24, viii, 301-2;
discovered by Kirchhoff, ii, 17

Spectrum Colors, eye receptors of, xi, 89-90

Speculum, defined, vi, 102

Speech, advantages over sign language, xv, 151-2;
dense atmosphere effects on, iv, 32;
emphasis importance in, xv, 144-5;
evolution of, 152-4;
physical factors of, ix, 83;
power of, in man and animals, xv, 68, 91, 141

Speech Organs, tendency to respond to sound, xi, 103

Speed, perception of, xi, 165 (see Velocity)

Speed Boats, vi, 192

Spelling, English, xv, 176-8

Spencer, Herbert, evolution taught by, x, 136;
on education, 282, 284;
on evolution, xvi, 152;
on origin of priests, xv, 350;
on relativity of knowledge, xvi, 195-6

Spermaceti, xii, 299

Spermatozoön, origin of energy, xvi, 145

Sperm Cells, production and development of, ix, 332-3, 335, 339

Sperm-Whale, xii, 298-9

Sperry, Elmer A., v, 343

Sphagnum Moss, xiii, 69, 160-3, 166

Sphalerite, iii, 339, 363, 364

Sphincter Muscles, ix, 85;
fear effects on, xi, 132;
of stomach, ix, 231, 232, 233, 234, 236-8;
operation, xi, 37-9

Sphinx, erosion of, iii, 73

Spice Bush, xiii, 196, 351

Spices, xiii, 259-65;
effects on stomach, ix, 243-4;
food value, viii, 366;
in preserving, 372;
sensation from, ix, 98

Spiders, xii, 90-7

Spiegeleisen, v, 320

Spike, flower form, xiii, 50;
of grasses, 181

Spinach, origin, xiii, 223-4

Spinal Column, ix, 64 (fig.), 65;
in infants, xv, 81;
in man and apes, 57-8;
in vertebrates, 55-6;
ligaments of, ix, 71;
notochord of, xii, 128

Spinal Cord, ix, 131, 133 (fig.), xi, 25-7;
inflammations, cause of, x, 224;
medulla of xi, 28;
nerve connections through, ix, 130 (fig.);
neurones, xi, 21

Spinal Nerves, ix, 131-2, xi, 25-6

Spindles, ancient, xv, 244, 245 (fig.)

Spine, tuberculosis of, x, 92

Spinning, by Lake Dwellers, v, 14;
historical development of, xv, 243-4, 246

Spinning Jenny, invention, xv, 246

Spinning Machines, v, 273, 274-6, 376, 378

Spinning Wheels, v, 268, 273, 274;
development of, xv, 244

Spinosa, philosophy of, xvi, 117

Spinosity, in animals, iii, 277

Spiral Gears, v, 38-9

Spiral Hypothesis (see Planetesimal Hypothesis)

Spiral Nebulæ, ii, 361-5;
discovery, 17, 106, 186, 380;
distances, 124;
distribution, 355, 356;
globular clusters and, 337;
Jeans on origin, 378;
new stars in, 333;
new universes, 381;
origin, planetesimal theory, 372-4, iii, 160-2;
star streaming and, ii, 348-9;
studies at Mt. Wilson, 157-8;
transition from nebula to star, 136

Spirilli (bacteria), x, 195

Spirits, savage belief in, xv, 331, 332, 337-40, 348-9, 350, 358

Spirits of Wine, viii, 213-14

Spirometer, x, 339

Spitball, effectiveness of, iv, 69

Spitting, indiscriminate, x, 291

Spitting Adders, xii, 227

Spitzbergen, coal deposits, i, 199;
flora of, xiii, 341-2;
ice-caps of, iii, 61

Splanchnic Nerve, xi, 273

Spleen, functions of, ix, 184, 275

Split-Phase Starters, vi, 250

Spoken Language, evolution of, xv, 152-4

Sponges, iii, 259, 266, xii, 23, 30-2

Spongin, xii, 31

Spontaneous Combustion, viii, 55-6

Spontaneous Generation, x, 139;
history of doctrine, xvi, 114;
origin of life by, xii, 10

Spoonbills, xii, 151, 256

Sporangia, xiii, 155

Spore-habit, relics in cycads and ginkgo tree, xiii, 309, 316

Spores, xiii, 64;
dispersal by winds, 344;
fermentation by, viii, 248;
in atmosphere, i, 61;
of anthrax bacillus, x, 149;
of ferns, xiii, 155-7, 159, 160;
of moss, 69, 162;
of mushrooms, 163, 164

Sporogony, x, 159

Sports (mutants), ix, 342, xiii, 333-4

Sporulation, x, 155

Spotted Fever, cause of, xii, 98

Sprague, F. J., vi, 26

Spring, frosts, i, 257-8;
rate of advance in U. S., i, 256

Spring Balance, iv, 58-9, 102

Springboks, xii, 327

Springhaas, xii, 289

Springs, iii, 116-17, xiv, 137-9;
drying of, 136;
fissure, 138, 152;
fluctuations and constancy, 152;
forests and, 379;
Havana water supply from, 140;
hillside, 137-8;
in river formation, 175-6;
in western canyons, iii, 116;
"juvenile," xiv, 151-2;
lacking in clay soils, 137;
mineral matter in, viii, 195
(see also Hot Springs, Mineral springs)

Springs (mechanics), air-cushioning of, v, 134;
energy of, iv, 82, 87-8;
pneumatic, v, 126;
storage of energy in, 126

Spring-tails, xii, 104

Spring Tides, ii, 70, xiv, 292

Spruce, traveler, i, 352

Spruce Forests, xiii, 367-8;
in relation to winds, 149

Spruce Trees, dominance in north, xiii, 350;
in northern forests, xiv, 372, 374;
nativity, xiii, 244;
paper pulp from v, 292, 293, xiii, 10, 234, 244;
planting conditions, 270;
polycotyledons, 61;
roots, 17
(see also Conifers)

Sprudel Spring, xiv, 152

Spur Gears, v, 29

Spurges, antiquity, xiii, 324-5;
South Africa, 355, 379;
rubber from, 249;
stems, 28-9, 30-1

Sputum, tuberculosis spread by, x, 291, 292, 293-4

Squalls, i, 382

Squash, origin, xiii, 224

Squaw Winter, i, 361, 382

Squids, xii, 79-80;
deep sea, 23;
phosphorescence of, 20;
whales and, 299

Squirrel-cage Induction Motors, vi, 245;
on farms, vii, 224

Squirrels, xii, 291-4;
antiquity of, 286;
arboreal habits, 285;
man's lesson from, xv, 206;
storing of fruits by, xiii, 56, 340;
sugar, xii, 278

Stabilizers, gyroscopic, v, 341-2

Staffa, hexagonal columns of, xiv, 129, 130

Stags, xii, 317;
age of, xv, 100 (fig.)

Stahl, George Ernst, x, 84-5, 301

Stained-glass Windows, preparation of designs for, iv, 342

Stalactites and Stalagmites, iii, 127, viii, 151, xiv, 148;
rate of formation, xv, 79-80

Stalks, of plants, xiii, 27

Stalling, of motors, v, 157

Stamens, xiii, 45, 46;
arrangement in various flowers, 123-46, 181-207;
in grasses, 182;
of highly cultivated plants, 51;
in reproduction, 117, 119, 120, 121, 122

Staminate Flowers, xiii, 46-7

Stamping, of feet, in excitement, xi, 356

Standard, of flowers, xiii, 47-8

Standard Barometer, iv, 119-23

Standardization, in manufactures, v, 48-52, 53-4, 55-6

Standing, correct posture in, ix, 57, x, 305;
heart beat in, ix, 207

Stanley, Henry M., African trip, xiii, 359, 361

Staphylococci, x, 195

Star Anise, origin, xiii, 255

Star Apples, origin, xiii, 227

Starch, composition and properties, viii, 227-8;
digestion of, 357, ix, 230, 235, 242, 292, x, 270, 326, 330;
fermentation, viii, 225, 248, 249;
food value, 365, ix, 300, x, 259, 262, 269, 271
(see also
Carbohydrates);
food amounts in ordinary diet, ix, 290, 300-1;
foods for infants, 346;
glucose production from, viii, 225, 228, 241, 243-4;
iodine effects, 228, 294;
made from rice, xiii, 213;
making of, by plants, viii, 335, 349, ix, 27-8, 28-9, xiii, 79, 80,
83-4, xiv, 65;
manufacture and uses, viii, 243;
tastelessness of, 366

Star Charts and Catalogues, ii, 298-9, 300-3;
early, 29, 31, 34, 39, 45, xvi, 90,
(see also Draper Catalogue)

Star Classification, by color, ii, 296-8;
by giant and dwarf theory, 309;
by magnitude, 295-6, 297;
by spectra, 115-18, 307-10;
by temperature changes, 309-10

Star Clouds, ii, 357-60

Star Clusters, ii, 122, 336-40;
moving, 341-4;
nebulæ and, 357;
photography of, 136

Star Distances, ii, 311-18;
ancient ideas, 28, 350;
brightness in relation to, 322;
first measurement, 16;
methods of measuring, 124, 153, 311-13, 316-18;
of Galaxy, 355;
of globular clusters, 337, 338-9, 340;
of nebulæ, 358;
of spiral nebulæ, 363;
of Sirians and Solars, 122, 353;
unit of measurement, 315-16, xvi, 33-4

Star Distribution, ancient and modern conceptions, ii, 350, 352-3;
Galaxy as basis, 350, 351, 352, 353, 354, 364-5;
globular clusters, 338, 339

Starfishes, iii, 259, 268, 269, 270, xii, 49-50

Star Flowers, xiii, 203

Starling, Prof., quoted, xi, 154, 182;
secretin discovery, x, 325

Stars, aberration orbits, ii, 90-1, 92;
actual dimensions, 321-4;
angular diameters, 150-1;
brightness (see Magnitude of Stars);
Classification (see Star Classification);
constitution, 382-3;
constitution determined by spectra, 17, 113, 114-18;
distances (see Star Distances);
distribution (see Star Distribution);
evolution order, 116-17, 308-9, 310, 383;
evolution seen in spiral nebulæ, 362;
giant and dwarf, 153, 294, 309, 310, 382-4;
light, 296, 16;
light-intensity, vi, 272;
light of, in space, iv, 334;
magnetism, ii, 178;
magnitudes (see Magnitude of Stars);
motions (see Motus Peculiaris, Proper Motion, Star Streams);
multiple, 335;
naming of, 302-3;
nearest, 319-20;
nebulæ and, 308-9, 365, 381;
nebulous, 360;
new or temporary (see Novae);
number, 294-5;
origin, Jeans on, 378-9;
parallax (see Parallax);
photography in study of, 135, 137;
planets of, 252-3;
radiant energy, 384;
radiative equilibrium, 383-4;
right ascension and declination, 299, 305;
spectral type, 115-18, 307-10;
spectra affected by atmospheric ozone, i, 16;
transit measurement by eye-and-ear method, xi, 155-6;
twinkling, to what due, i, 174;
universe of, ii, 294-9;
variable (see Variable Stars);
worship in ancient Egypt, 24;
why unseen by day, i, 164

Star Streaming, ii, 306, 317, 345, 347;
Jeans on origin, 378

Star Streams, ii, 345-9;
nearest stars in, 320

Starters, automobile, vii, 120, 127, 135, 142-8;
of motors, vi, 236-9, 250-5, 262-3

Starvation, x, 275;
diabetes treatment by, ix, 294;
sense of hunger in, 88;
waste of tissues in, 297-8;
weight reduction by, 302

Stassfurt Deposits, viii, 196, 278-9, 344, xiv, 67, 209

States of Aggregation, iv, 22

States of Matter (see Physical State)

Static, technical meaning, iv, 383

Static, in wireless (see Strays)

Static Breeze, vii, 238-9

Static Electricity, iv, 259, vi, 284-305, vii, 375;
lightning as, 205, 206, 207-9

Static Generators, vii, 245

Static Induction Machine, vii, 236

Static Sense, xi, 126

Statics, defined, iv, 25, 383;
early development of, 25, 27

Stationary Waves, iv, 217

Statue of Liberty, lighting, vi, 283

Statues, coloring of, xv, 300, 302;
primitive, 118, 120

Stature, artificial selection, xvi, 154, 157;
in relation to food, xiii, 172;
of various European groups, xvi, 48, 49;
of various races, xv, 38-9;
rate of growth in man, ix, 32 (diagram)

Steam, density of, iv, 113;
dry and wet, v, 140;
exhaust, vi, 355;
invisibility of true, i, 90;
latent heat of, iv, 188, v, 354, viii, 38;
saturated and superheated, v, 140;
saturated, pressure of, iv, 168;
specific heat of, 155, 187;
specific heat ratio, iv, 156;
use in engine and turbine, v, 142

Steamboats, early, v, 189-90, 192, 377;
early dangers, i, 49-50

Steam Boilers (see Boilers)

Steam Carriages, v, 207-8, 212

Steam Electric Plants, vi, 351, 353-61;
size of generating units, 378-9

Steam Engines, efficiency, on what dependent, iv, 192;
estimate of work of, 193-4;
history and principles, v, 139-48, 376;
in power plants, vi, 354-5, 357-8;
invention and consequences, xvi, 125, 126;
origin in kitchen, v, 109;
reciprocating compared with turbine, 152-4;
starting of, vi, 235;
temperature and pressures in, v, 139-40;
waste of heat energy, 155;
Watt's, 44, 47, 144-6, 376, 377

Steam Hammer, invention, xvi, 175;
Nasmyth's, v, 379

Steam Heat, dryness of air from, xiv, 353

Steam Heating System, iv, 186-7, xiv, 353

Steam Navigation, development, v, 189-90, 192-4

Steam Power, disadvantages in mining, v, 128-9;
from subterranean heat, 180-1;
from sun's heat, 177-8;
from volcanoes, 179-80;
waste of heat energy, 155

Steam Reserve, of power plants, vi, 367

Steamships, development of ocean, v, 192-4, 378;
glass-enclosed machinery, vi, 175;
propellers (see Propellers);
speed, power and lines, v, 191-2;
turbines on, 105, 153
(see also Ocean Steamers)

Steam Shovels, v, 252-3, 262

Steam Traction, beginnings, v, 207-8, 212

Steam Turbines, v, 148-54, 382, vi, 354-5;
connection with ship propellers, v, 105-6, 153-4, vii, 329-30;
efficiency, v, 155, 172;
Hero's, xvi, 92, 93;
most efficient speed, vii, 329;
speed-limiting device, 49;
use of steam in, v, 142

Stearic Acid, viii, 220, 221, 350

Stearin, glycerine from, viii, 247

Steatite, iii, 339

Stebbins, astronomer, ii, 212, 328

Steel, alloys of, xiv, 238;
composition and properties, viii, 159-60;
cutting of, vii, 321;
elasticity of, iv, 36;
expansion by heat, 145, v, 71;
magnetism of, iv, 245, 251, vi, 36-8;
purification in electric furnaces, vii, 304;
structure of hard and soft, iv, 37;
silicon in, viii, 90
(see also Steel Making)

Steel Engravings, by electrotype, vii, 314

Steel Making, v, 319-25, 380, 383, viii, 159-60, 273, xvi, 174-5;
electric furnace in, vii, 301, 305, 312;
phosphorus obtained from, viii, 345

Steel Mills, electromagnets in, vi, 35, 86;
great motors, 228-9;
rise of body temperature in, ix, 317

Steel Rails, electric furnace steel for, vii, 312;
expansion by heat, iv, 134;
friction, v, 204, 206;
manufacture, 322-3

Steel Shipments, meteorology in, i, 269

Steel Ships, v, 195;
compass variations in, iv, 254, v, 340, vi, 42

Steel Structures, electrolytic corrosion, vi, 64-6;
in earthquakes, xiv, 343

Steel Tracks, for trucks, v, 206-7

Steenheil, K. A., xvi, 191

Stegocephalia, xii, 168

Stegosaurs, iii, 289-90

Steinboks, xii, 326, 327

Steinmetz, C. P., vi, 26

Stejneger, Dr. Leonard, xii, 226, 234