Chapter XVII: Science in the Twentieth Century (1)

It is obvious that we are now in a great period of transition. Scientific discoveries came so quickly at the end of the last century that a recasting and readjusting of scientific conceptions had to be undertaken. This process was in progress when the World War began. The world-wide disturbance led to temporary scientific infertility except in such directions as served the purposes of war. But therein science became allied more closely than ever before with certain branches of industry, and the cooperation thus established has been recognized in all civilized countries as of the utmost value to the future progress of mankind.

The philosophic thought of each era generally develops in harmony with social and intellectual conditions. The philosophical doctrines of the leading writers may, therefore, be taken as representative of the spirit of their age. When Darwin in the middle of the last century published his doctrines of evolution, of the struggle for existence and the influences of living conditions upon survival of species, philosophy turned away from the utilitarianism and tolerance of Hamilton, Hume, and Mill and the positivism of the French to the synthetic evolutionism of Herbert Spencer. One of the basic teachings of Spencer was the relativity of knowledge. The process of thinking involves relation, difference, and likeness. This is merely relationing. Therefore no thought can ever express more than relations. The primary act of thought through which we discover likeness and difference underlies all our knowledge.

A reaction against this new empiricism began in 1898, when William James published his "Philosophical Conceptions and Practical Results." This work popularized the philosophy of pragmatism which denies the absoluteness or ultimateness of the traditional antithesis between theory and practice and relies for its justification upon the fact that everything which we think about, and do, must first be willed. Reality consists in pure experience quite independent of thought. Bergson developed this philosophy of practicalism further and taught that knowledge of reality comes through intuition and that life is merely intuitive knowledge. Intuition, is deeper than scientific reason because it feels, and links us with, the eternal processes of nature.

Philosophic thought is now temporarily influenced by the revival of an old principle known as the principle of relativity. The popular name for this is the Einstein theory, because in 1905 Albert Einstein, working on some theories developed by Lorentz and Fitzgerald, published his first principle of relativity which suggested that the velocity of light is constant, however the position of an observer may vary and that space and time are variable. In 1917 Einstein enlarged this idea in order to include all the laws of nature.

Space and time are treated as just mental concepts. They lack the concreteness of matter, but they compose the framing of the universe and give it form and continuity. Consequently we see so much of them that we attribute reality to them. The theory of relativity suggests that time is not continuous. There is no identity of instants at different places. The present instant really does not extend beyond this immediate point. At other points there are instants older, younger, and contemporaneous with this instant. They are, however, quite distinct from this one. In order for an instant to be simultaneous it would be necessary that it should occur at the same point.

An object or event gains its substance and form from activities of our minds. Any meaning or significance that an object or event has is also derived from our minds. The reality of the universe is an activity, or series of activities, which are manifested in life and mind.

The relativity of space is illustrated by an example given by Professor Henri Poincaré. Assume that I meet you in Wall Street, New York, and say, "I will meet you here again at this time to-morrow." You promise to do so. But you could not keep such a promise except with regard to position on the surface of the earth, because between now and to-morrow the earth will have moved over an enormous distance carrying Wall Street and a great mass of other things with it. The sun also will have moved away the stars, carrying the earth with it.

Another interesting mental picture is drawn by Professor Herbert Wildon Carr to illustrate the philosophical meaning of the principle of relativity. Suppose that on a very frosty morning we were to see a watery vapor in the air we breathe condense into a little cloud and after floating around a while gradually disappear and become reabsorbed in the atmosphere. Assume that at the moment of this reabsorption we should undergo an instantaneous transformation of all our proportions so that our new dimensions become infinitesimal in comparison with our former state. Do you think that we would recognize the fact that we had changed? The theory of relativity declares that we would not know what had happened, because with the alteration in proportions the ratios would remain constant. The change would express itself in the new dimensions of objects around us. The little globules of water composing the little cloud would now appear like stars and planets occupying immense areas in distant spaces, far apart from each other, and all undergoing a slow age-long evolution. Such a change would be signalized as a new time and a new space.

Yet the principle of relativity does not appear to our physical senses to represent a truth of nature. It is noteworthy that the principle of relativity is usually invoked when conditions are unstable, when thought is confused, and when a period of readjustment is in progress. Thus the Einstein theory may be representative of present-day harmonies, but yet may prove, in the future, to have been merely a passing philosophic mood.

Bagehot, a shrewd observer, writing in 1868 about the changes wrought by Darwin's evolutionary theory, said: "There is scarcely a department of science or art which is the same, or at all the same, as it was fifty years ago. A new world of inventions has grown up around us which we cannot help seeing; a new world of ideas is in the air, and affects us though we do not see it." Those were very true words more than half a century ago, yet they serve to describe present conditions!

GENERAL INDEX

A, vowel sound, record of, iv, 234

Aard-vark, xii, 281-2

Abacus, or calculating machines, xv, 183-4, xvi, 61

Abalones, xii, 71

Abbe, Prof. Cleveland, i, 216-17

Abbot, Dr., solar studies, ii, 171, 186-7

Abdomen, blood circulation in, ix, 196, 197;
methods of examination, x, 147, 371;
muscles of, ix, 77

Abdominal Organs, control of circulation of, ix, 215, 216, 217, 220;
development of, in black and white races, xv, 50;
mesentery support of, ix, 59;
smooth muscles in, 160-1

Aberration of Light, ii, 91-2

Abert, Lake, Oregon, xiv, 203

Abnormal Complexes, x, 355-6

Absaroka Range, xiv, 104-5, 226

Abscesses, cause (germs) of, x, 195, 198, 221;
cure of neurasthenic, 58-9

Absinthe, source, xiii, 266

Absolute, technical meaning, iv, 381

Absolute Magnitude (stars), ii, 317;
Adams' method of determining, 124, 153;
spectral type and, 115, 317;
used in measuring star distances, 318, 330

Absolute Maximum & Minimum (meteorology), i, 204, 365

Absolute Scale (thermometry), i, 73, iv, 141, viii, 107-8

Absolute Units, iv, 64, 69, 70

Absolute Zero, i, 73, iv, 141, v, 347-8, viii, 107-8;
molecular condition at, iv, 142-3, viii, 108;
nearest approach, i, 32, iv, 173, xvi, 194;
of outer space, vi, 270

Absorption Lines, ii, 111-12 (see Fraunhofer Lines, Spectrum)

Abstract Ideas, difficulty of attention to, xi, 228, 233-4;
expression of, in primitive language, xv, 144-150

Abul Wefa, Arab astronomer, ii, 38

Acceleration, definition & measurement, iv, 57, 381;
force in relation to 59-61, 63-4, 71-2;
of gravity, 65

Accidents, from electricity, x, 254;
from fatigue, xi, 274;
prevention of, vii, 32-3, xi, 365

Accidents (geological), xiv, 188

Accommodation, of vision, ix, 110-11, 113;
muscles of, 161, 162

Accumulators, storage batteries, iv, 300

Accumulators, water-pressure, v, 106

Accuracy, habit and, xi, 253;
indifferent types of men, 156, 157, 158-9

Acetic Acid, vi, 111, viii, 220;
solubility, 112;
in vinegar, 218, 249, 293

Acetylene Gas, discovery, xvi, 190;
formation, vii, 312;
in steel making, 321;
luminosity of flame, viii, 60;
preparation & uses, 231

Achenes, xiii, 58-9, 344, 345

Acheson, Dr. Edward G., vii, 300-1, 309-10, xvi, 189-90

Acheulean Implements, xv, 105, 107

Achromatic Lenses, iv, 373;
invention, xvi, 125-6

Achromatic Refractors, ii, 100-1, 103

Acidosis, x, 280

Acids, viii, 19-20, 114-15, 373;
action on saccharides, 226, 228;
amino, 230 (see Amino Acids);
bases and, 115;
defined by ionization theory, 122;
electrolytes, 125;
formation, 20, 39, 118, 373;
formation in body, x, 280-1;
hydrogen prepared from, viii, 32-3, 102;
ionization in solution, 119-25, 300-1;
manufacture of, 275-6;
molecular structure, 218;
molecular structure & physical state, 298;
nomenclature, viii, 98;
organic, 52, 219-21;
oxygen in, 34;
salts formed from, 72, 83, 114, 373;
vegetable, 222-3, 336, 349;
volumetric analysis of, 292-3

Acid Salts, viii, 116

Acne, causes of, x, 201, 311

Aconite, xiii, 252

Acorns, xiii, 193;
dispersal by squirrels, 55-6, 340;
survival rate, xv, 21

Acoustic Clouds, i, 190

Acoustics, atmospheric, i, 186-96;
of auditoriums, iv, 239
(see also Sound)

Acquaintanceships, selection of, xi, 257, 380-1

Acquired Characters, inheritance of, ix, 325-7, x, 230

Acquired Tastes, xi, 72-3

Actinic Rays, iv, 365-6, 381, vii, 250, 361

Actinolite, iii, 321-2

Action & Reaction, iv, 33-4, v, 143;
Newton's law, ii, 66, iv, 69

Activity, food needs dependent on, ix, 295, 296, 297;
mind as, xi, 12, 13, 236;
temperature effects on, i, 323-4

Activity (mechanics), iv, 80

Adaptations, of eardrum to sound, xi, 100;
of eye to colors, 95;
of nose to odors, 80-1;
of skin to pressures, 111;
of tongue to tastes, 72;
to warmth and cold, 113

Adaptation to Environment, xv, 16;
by animals, 16-18;
by man, 3, 25, 26, 28, 31, 36;
by plants, xiii, 11, 12, 28-31, 89-90, 149-50, 346, 355-83, xv, 16,
18-19;
between insects & plants, xiii, 144, xvi, 152-3;
mental efforts at, x, 361-2;
natural selection and, xv, 24-5;
principle never perfect, xvi, 152-3
(see also Environment, Environmental Variation)

Adder's Tongue Fern, xiii, 159

Adding Machines, v, 326-7

Addison, Thomas, x, 106, 112

Adenoids, ix, 104, 224, x, 341-2;
as infection foci, 220

Adenoid Tissue, ix, 223, 224

Ader, C., v, 231

Adiabatic Changes, iv, 158-9, 381

Adipose Tissues, ix, 298

Adirondack Mountains, age, iii, 191;
club mosses in, xiii, 305;
erratic bowlders in, iii, 70;
fault blocks in, 89;
fault lines and streams, xiv, 128;
granite formation, iii, 112;
Grenville strata, 165, 167;
ice age survivals, xiii, 321;
iron district, iii, 359;
lakes, how formed, 145;
lightning effects, 24;
Ordovician strata eroded, iii, 186;
quartz & slate formations, xvi, 29

Adjutant Bird, xii, 255

Admiration, sentiment of, xi, 146-7

Adolescence, mental conditions of, x, 236-7

Adrenalin, ix, 171-2, 209, 219, xi, 137, 138, 273

Adrenals, ix, 170-1;
Addison's disease of, x, 112-13;
functions, xi, 60, 137;
shock effects, 59

Adriatic Sea, bora, i, 133;
coasts of, xiv, 252-3, 263;
filling in by deltas, 53;
Karst district, 150

Adsorption, viii, 316, 373

Adulteration of Food, viii, 370-1

Adults, basal metabolism in, x, 271;
growth in, ix, 287, 288-9;
heart rate in, x, 334;
protein needs of, ix, 281-3

Advance Metal, resistance, vi, 77

Advertising, psychology of, xi, 343-9;
sign & display, vii, 339-43;
tied images in, xi, 221;
weather considerations, i, 255-6

Ægean Sea, volcanoes, xiv, 317, 319

Æolian Tones i, 195

Aerial Echoes, i, 190, 193

Aerial Roots, xiii, 20-2;
of fig tree, (illus.), 48

Aerials, iv, 314, vii, 261;
Dolbear's patent, xvi, 191;
in aeroplane sets, vii, 282
(see also Antennæ)

Aeroclinoscope, i, 282, 365

Aerology, i, 18-19, 20-3, 89, 365-6

Aeronautical Meteorology, i, 284-305

Aeronautics, accidents & safety questions, i, 49-50;
accidents in World War, x, 246;
aneroid barometer importance in, iv, 124;
fog in, i, 94, 95, 300-2;
history & future, 39-51;
Langley's work in, iv, 43-4;
pilot balloons in, i, 22;
therapeutic possibilities, 51;
weather importance, 284-6;
wind & air currents, 126, 130, 289-300
(see also Aeroplanes, Balloons)

Aeroplanes, altitudes attained, i, 22, 46;
altitude effects, 303;
astronomical use, ii, 208, 212, 225-6, 382;
Brocken specters seen from, i, 185;
engine efficiency, v, 170;
gyroscopic stabilizing, 343-4;
helicopter, i, 42;
history & development, 40-1, iv, 43-4, v, 230-3, 382, 383-4;
landings, i, 42, 45, 294 (fig.) 302;
mail service, 44-5, vii, 76;
meteorological uses, i, 22;
passenger, 41-2, 43-5, 50;
photographic mapping by, 45-8;
principles, i, 286-305, v, 233-8;
propellers (tractors) of, iv, 34;
radiotelephony and, vii, 282-3;
rise or "taking off" of, iv, 43;
safety question, i, 49-50;
stereograms from, xi, 180-1;
uses, present & future, i, 41-2, 43-9;
war uses, v, 107, 372-3, 375;
wind effects, i, 285-6, 289-300;
wireless directing, vii, 283;
World War, i, 185, 308, 312, vii, 283, x, 246
(see also Aeronautics, Aviators)

Æsculapius, x, 16, 17;
temples of, 17, xvi, 44

Æsthetic Arts, development of, xv, 297-324

Æsthetic Instinct, xvi, 47, 48

Æther of Space, vi, 118-20;
constitution, vii, 368;
elastic solid theory, xvi, 137;
universal presence of, iv, 180-1

Æther Waves, various kinds, vi, 119, 269, vii, 249, 250, 259-61, 371

Aetius, medieval writer, x, 31

Ætna (see Etna)

Affection, emotion of, xi, 147;
importance, 129;
seat of, ix, 200

Africa, animals of (carnivora), xii, 339, 342, 344, 345, 348, 352-3,
355, 356-7, 359, 360, 365;
animals,(herbivora) xii, 302, 303, 304-5, 308, 310, 320-1, 327-8, 329;
anteaters of, 281;
antiquity of man in, xvi, 64;
bats of, xii, 370;
birds of, 249, 260, 266, 267;
"bush" lands of, xiv, 378-9, 380;
coasts & islands, 251-2, 263;
coasts contrasted, xii, 40, xiv, 305;
coffee production in, xiii, 233;
crocodiles, xii, 199-200;
drainage system, xiv, 190;
dust haze, west coast, i, 55;
elephant-trapping in, xv, 225;
exploration of, xiv, 196-7;
forests of, 366, 368-9, 382;
fishes of, xii, 151, 154, 160, 166;
former submergences, iii, 216, 235;
geographical features & results, xv, 136;
Gold Coast, death rate on, 50;
grasslands in south, xiv, 384;
health conditions, 197, 223-4;
lemurs of, xii, 374, 375;
lizards, 208;
monkeys & apes, 379, 380, 383;
palm oil, importance to, xiii, 11;
plains of, xiv, 217-18;
plateau of interior, 196, 221, 222;
rivers, broken courses, 155;
rivers, navigability of, 196;
rock weathering in central, 78;
rodents of, xii, 288, 289-90;
rubber production, xiii, 248;
salt lakes, viii, 139;
short races of, xv, 38-9;
sleeping sickness in, x, 167-70;
smallpox superstition of natives, 285-6;
snakes of, xii, 214, 226, 227-8, 231-2;
timber supplies, xiv, 382;
vegetables originating in, xiii, 222-7;
volcanoes & lava fields, xiv, 317;
yellow fever on coasts, x, 160
(see also East, North, South, West Africa)

African Savages, body decoration of, xv, 256, 257-8;
debtors, treatment of, 370;
language changes, 155;
rule of fathers among, 367
(see also Bushmen)

African Sleeping Sickness, x, 167-70, 199, xiv, 197, 223, 357;
chemotherapy in, x, 381;
Koch's work on, 150, 169

After-Images, xi, 90-2, 220;
of sun (green flash), i, 171

After-Summers, i, 362, 366

Agassiz, Lake, iii, 144, xiv, 201;
plain of, 215-16

Agassiz, Louis, discoverer of Ice Age, iii, 236;
on fish scales, xii, 134;
on snapping turtles, 188

Agate, iii, 337

Age, chronological & physical, ix, 214;
effect on disease, x, 236-7;
growth in relation to, ix, 288-9

Agonic Lines, iv, 246, 247

Agoutis, xii, 289

Agramonte, Dr. Aristide, x, 160, 200

Agricultural Chemistry, viii, 334-47
(see also Fertilizers, Nitrogen, Potash, Soils)

Agricultural Implements & Machinery, v, 239-50, xv, 235-6;
Egyptian, xvi, 72;
electricity in, vii, 230

Agricultural Meteorology, i, 245-60

Agricultural Stage, xv, 187, 199-203;
polygamy in, 288;
rulers in, 367

Agriculture, ancient centers of, xiii, 221;
beginnings of, 209-10, xv, 200-2;
civilization and, 128;
fundamental importance, xiv, 218;
grasslands and, 383;
plains most favorable to, 218-19;
possibilities, by what determined, 64;
summer rain importance, 352

Ailerons, i, 289, 299, v, 238, 343

Air, amount consumed by breathing, ix, 256;
ancient ideas, xvi, 79;
as balloon ballast, v, 226;
boiling point of, iv, 173;
buoyant power of, 107, 108;
burning of, in gas, viii, 55, 56;
burning, in gasoline engines, v, 156-7;
"change of" (vertical), i, 51;
closeness or stuffiness of, (see Ventilation);
combustion and, i, 10;
composition, 9-16, vii, 321, viii, 66-8, ix, 254, 268;
composition, discovery of, xvi, 120, 121;
compressed (see Compressed Air);
compressibility, v, 126;
cooling power, i, 318, 319-21;
critical temperature & pressure, iv, 172, 173;
decay in relation to, xiii, 312-13;
density of, iv, 113, 198;
drying power, i, 77, 323;
dryness & dampness, viii, 67, xiv, 353-4;
elasticity of, iv, 198, v, 126;
electrical conductivity, i, 144-5, iv, 259, 265;
expansion by heat, 151;
frozen, v, 345;
health benefits of special types of, x, 241;
heat conductivity, iv, 178, 179;
ionization, i, 142-4, 146, 150;
life without, (see Anaërobic);
liquefaction of, iv, 171, 172;
(see Liquid Air);
moisture capacity, xiv, 352-4
(see also Humidity);
molecular velocity in, iv, 133;
necessity to life, ii, 244, 245;
necessity to plants, xiii, 102, 109;
physics of, historical development, iv, 28-30;
popular & scientific conceptions, i, 9-10;
pressure of, iv, 132
(see also Atmospheric Pressure);
purifying by ozone, i, 15, vii, 354;
purity tests, i, 321-2;
resistance due to inertia, v, 234;
resistance effects on aeroplanes, i, 286-9, iv, 43, v, 235-6;
resistance to falling bodies, iv, 42, 97;
resistance to projectiles, v, 369;
saturated, i, 14, viii, 67;
shimmering of, i, 174, iv, 328, 329;
in soil, xiii, 92;
solubility in water, viii, 111;
sound transmission by, i, 186, iv, 195, 198-9, 201, ix, 98-9;
specific heat of, iv, 161;
specific heat ratio, 156;
surfeit of, bodily effects, 31;
ventilation of, (see Ventilation);
vibrations of, 215;
warming of, by sunshine, 182;
warming of, by freezing water, 161;
weight of, 107, 116, 124, v, 221-2, 230;
weight, discovery of, iv, 29, 114-16;
weight of heated, v, 223
(see also Atmosphere)

Air Bladder, xii, 135-6, 164-5

Air Brakes, iv, 129, 200, v, 130-3, 380, 381;
on electric cars, vii, 185-6

Air Columns, resonance of, iv, 226-31;
vibrations of, 215

Air Compressors, i, 26-7, iv, 128, v, 89-93, 127-8

Air-cooled Engines, v, 160-1

Air Currents in aeronautics, i, 293-300;
pilot balloons to discover, 21-2

Air Cushioning, v, 133-5

Air Holes, i, 298-9, 374, v, 224

Air Jets, v, 135-6

Airlifts, iv, 130, v, 114-15

Air Locks, v, 118-19, 124

Air Pumps, iv, 126-7

Airships, in forest service, i, 49;
future landing places, 43;
future uses in transportation, 42-3;
high altitude effects, 303;
history of development, 40-1;
possibilities of, iv, 107-8
(see also Dirigible Balloons, Zeppelins)

Air Springs, v, 126-38

Air Waves, i, 294 (fig.), 298

Akeley, Carl E., v, 136

Alabama, aluminum production, iii, 369;
chalk deposits, 216;
coal beds, 199;
iron production, 358-9;
soil of, xiv, 218

Alabaster, iii, 331, 332, viii, 149

Alaska, animals of, xii, 318, 319, 320, 337;
auks of, 265;
blackfish of, 163;
coal fields, iii, 348;
coast changes, earthquake of 1899, 97, xiv, 34, 114, 334-5;
coast formations, iii, 57;
fiord coasts, xiv, 258, 259;
glaciers, iii, 59, 60, 62, xiv, 55, 60;
gold production, iii, 366, 367;
ice age in, 239

Albania, story of unchangeableness, v, 251

Albategnius, ii, 38

Albatross, xii, 251-2

Albe, E. Fournier d', v, 332

Albucasius of El-Zahra, x, 32

Albumens (see Proteins)

Albuminuria, x, 345-6

Alcmæon, Greek anatomist, xvi, 82-3

Alcohol, (ethyl or grain), viii, 212, 213-14;
boiling point, iv, 168;
cooling by, 174;
conversion to acetic acid, viii, 218;
denatured, 250;
flame of, 60;
formula of, 218;
freezing point of water lowered by, 299-300;
frozen, v, 345;
frozen in liquid air, i, 31;
future motor fuel, viii, 209;
manufacture, 250;
per cent in distilled beverages, 250;
physiological effects, ix, 94, 214, 244, 248-9, 320-1;
production by fermentation, viii, 213-14, 248-50, ix, 248, x, 138;
solvent properties, viii, 217;
specific gravity of, iv, 112;
(see also Alcohols)

Alcoholic Drinks, viii, 249-50;
arterial elasticity impaired by, ix, 214;
food value, viii, 366, ix, 248-9;
in tropics, xv, 126-7;
stomach absorption increased by, ix, 244;
warmth produced by, 94, 320-1

Alcoholic Fermentation, viii, 248-9;
in body, ix, 248-9;
Pasteur's studies, x, 138

Alcoholometer, iv, 113

Alcohols, viii, 212-14, 373;
boiling points, 299;
double & triple, 215;
in esters, 221;
molecular complexity & physical state, 298;
in plants, 349;
relation to ethers, aldehydes & acids, 216-18, 219;
solubility, 37, 112

Aldebaran, angular diameter, ii, 151;
Arabic name, 39;
chemical composition, 114-15;
color, 297;
gaseous state, 382

Aldehydes, viii, 218, 219, 373;
in sugars, 225

Alder Flies, xii, 106

Alder Trees, xiii, 193, 271-2

Aleutian Islands, blue foxes of, xii, 344;
former connections, xiii, 351;
volcanic nature, iii, 106, 139, xiv, 315, 316

Alexander of Tralles, x, 31, 59

Alexanderson Generators, vii, 274-5, 290-1

Alexines, of blood, x, 210-11

Alfalfa, fertilization, xiii, 138-9;
in pea family, 198;
nitrogen fixation by, xiv, 66

Alfonsine Tables, ii, 39, 44

Alfred the Great, language of, xv, 156;
navy of, xiv, 261

Algæ, xiii, 72-3;
classification work, xvi, 166;
curious "showers" of, i, 358-9;
fossils of, xiii, 303, 304 (illus.);
found in hot springs, ii, 249, xiii, 299;
in sea, xii, 16-7, xvi, 147;
number of species, xiii, 323;
oldest of plants, 303-4;
reign of, 314, 323

Algeria, animals of, xii, 326, 359;
dust storms, i, 54;
record temperature, 209;
snowfalls, 210

Algol, actual magnitude, ii, 321-2;
secondary minimum, 328;
type of variables, 325-6

Algonquin Lake, iii, 149-50

Alimentary Canal, ix, 233 (fig.);
foci of infection in, x, 220;
in infants, ix, 346;
operation of muscles, xi, 37-8, 69;
protection against germs, x, 202;
sterile at birth, 201;
X-ray examinations of, 373

Alimentary Disorders, x, 319-38

Aliphatic, defined, viii, 373

Alkali Industries, viii, 276-8

Alkali Metals, viii, 132-47

Alkalis, defined, viii, 373;
deposits, 139;
volumetric analysis, 292

Alkaloids, viii, 240

Allbutt, Clifford, xvi, 184;
Osler and, x, 151;
quoted, 35

Allegheny Plateau, xiv, 221;
coal of, iii, 346-7;
origin of present relief, 231-2

Allelomorphs, xvi, 157

Allergy, x, 216-7

Alligators, xii, 182, 196-8;
savage methods of luring, xv, 222

Allotropic Forms, viii, 43, 87, 373

Alloys, viii, 272-3;
aluminum, iii, 369-70;
antimony in, viii, 169;
copper, 164;
electrolytic refinement, vii, 319-21;
melting point of, iv, 161-2

Alluvial Cones, iii, 33

Alluvial Soils, xiv, 63, 70-1

Almanacs, ancient Greek & Roman, i, 67-8;
Arabic word, ii, 39;
weather predictions in, 243-4
(see also Nautical Almanacs)

Alpenglow, i, 168, 366

Alphabet, invention & development of, xv, 175-6, xvi, 60

Alpha Centauri, magnitude, motion and type, ii, 319;
parallax and distance, 312, 313, 314-15

Alpha Lyræ, drift of sun toward, ii, 18, 306;
parallax, 312

Alpha Rays, i, 143, viii, 185

Alpine Glaciers, iii, 60, 62-3

Alpine Racial Group, xvi, 49-50

Alps Mountains, Alpenglow, i, 168;
Arctic species in, xiv, 365-6, 377;
chamois of, xii, 325;
foehn wall, i, 105;
forming of present, iii, 236, xiv, 233;
Glacial Epoch, lakes from, iii, 146, xiv, 200;
glaciers and snow line, iii, 59, 60, 62, 240, xiv, 55;
goats of, xii, 326;
hanging valleys and electric plants, xiv, 57;
historical and economic importance, 240-2, 243, 244, 245, xv, 137-8;
intense folding of, xiv, 36, 230;
lakes, iii, 143-46;
marine deposits, 235;
massif of, xiv, 234;
Napoleon's passage of, 244;
passes of, 58, 240-1;
population and industries, 241-2;
railways and tunnels, 240-1;
rainfall effects, 355;
rivers of, 167;
rock destruction by frost, 76;
snowfall measurement, i, 118;
solar heat at Davos, 210;
thickness of strata in, xiv, 229;
winds, i, 131-2, 133;
youthfulness of, xiv, 96

Alsace, potash deposits, viii, 279, xiv, 67-8, 209

Altamira, Spain, cave pictures, iii, 305, xv, 114, 116, 118, 298

Alternating Currents, iv, 307, vi, 153, 154-5, vii, 361;
ammeters for, vii, 166, 169-72;
carbon arcs on, 208-9;
circuit breakers for, 37-8, 40-1;
condensers' effects, vi, 304-5;
conversion to direct, 330-48;
cycles, 153, 154-5;
inductance, 166-7, 169 (see Inductance);
lag and lead phases, vi, 167-9, 171-4, vii, 362;
lighting and magnetic effects, vi, 155-7;
measurement of power, 165-9, 172;
Ohm's Law for, 164-5, 170;
sonic waves and, v, 108;
transmission of power by, vi, 159-60, 195-6;
uses, common and special, 152;
use in electric furnaces, vii, 305-6;
use in electrotherapy, 236-7, 244, 248-9;
use in traction, vi, 161-3, vii, 186, 196;
use in wireless, iv, 315, vi, 163;
voltage changed, 159-60 (see Transformers);
voltmeters for, vii, 154-5, 161-5;
wattmeters for, 172, 173, 177

Alternating Current Generators, iv, 307
(see also Alternators)

Alternating Current Motors, vi, 240-63

Alternation of Generations, xiii, 160, xvi, 166

Alternators, construction, types, and uses, vi, 157-9, 196-216;
operation in power plants, 357, 374;
ratings, 192-4;
synchronizing action, 383-4;
voltages attained, 159;
wireless, vii, 290-1

Altimeter, i, 72, 366

Altitude, barometric measurement of, iv, 124;
barometric pressure and, i, 23, 72, 171, 303;
climatic effects, xiv, 220, 223, 364-6;
potential variations with, i, 144-5;
pressure table, iv, 124;
rock weathering in relation to, xiv, 40;
sound and, i, 186-8;
temperature and, 19, 20, 303

Alto-Cumulus Clouds, i, 100, 101, 103, 298

Alto-Stratus Clouds, i, 100-3

Alum, Alums, viii, 312-13;
in water filtering, 320

Aluminum, Aluminium, affinity strength, viii, 128;
atomic weight and symbol, 383;
chemical activity, 149, 155;
compounds, unstable, 137, 257;
density of, iv, 113;
electrical conductivity, 283;
electrolytic reduction, vii, 320, viii, 271, 284;
gold plating of, vii, 319;
in heavy metal group, viii, 126-7;
melting point and heat, iv, 162, viii, 384;
occurrence, 19, 129, 148, 154, 198;
percentage in earth's crust, iii, 308, viii, 192;
production and uses, iii, 369-70, viii, 154-5;
salts astringent, 116;
sound velocity in, iv, 201;
specific gravity, viii, 384;
test for, 287, 288-9

Aluminum Arresters, vii, 17, 50

Aluminum Wire, vi, 80, vii, 23

Amalgam, defined, viii, 373

Amalgamation, defined, vi, 132;
in electric cells, 132, 139;
in gold and silver extraction, viii, 131, 270

Amaryllis Family, xiii, 188

Amatus Lusitanus, x, 58

Amazon River, arapaima fish of, xii, 154;
arrau turtle of, 193-4;
Black caiman of, 198;
electric eel of, 160;
forests and swamps, xiii, 360;
jaguars of, xii, 362;
length and volume, xiv, 189;
poison of natives on, xv, 228;
tributaries, connections, xiv, 187;
water boas of, xii, 216;
water lily of, xiii, 359-60

Amazon Stone, iii, 328

Amber, in varnishes, viii, 265;
insect remains found in, iii, 16, 280;
magnetism of, iv, 256, vi, 11, 12

Ambergris, xii, 299

Ambrose Channel, dredging of, v, 257-8;
sediment in, xiv, 269;
wireless pilot system, vii, 284-5

America, antiquity of man in, xiv, 149;
compass needle directions in, iv, 246;
discovery and settlement of, xiv, 309-11;
discovery of, effect on botany, x, 45;
first hospital in, 81;
plants restricted to, xiii, 320;
vegetables and fruits originating in, 222-7
(see North and South America)

American Buildings, dryness and heat in, i, 322-3, xiv, 353

American Colonies, Appalachian barrier, xiv, 191, 194, 242, 243, 249;
first hospital, x, 81;
independence results, 107;
medicine in, 81, 104;
ordeals practiced in, xv, 373;
westward growth by rivers, xiv, 193-4

American Indians (see Indians)

American System (Manufactures), v, 48-56, 213-14

Amethyst, iii, 337;
oriental, 327

Amides, viii, 373;
acid, 230

Amines, viii, 210, 214, 215, 373

Amino, defined, viii, 374

Amino Acids, chemistry of, viii, 230, 309-10;
physiological origin and use, ix, 279-84, 287-8, x, 204, 277, 278, 279;
proteins compose of, viii, 230, 351, 352

Amino Compounds, viii, 236-7

Amino Derivatives, viii, 210, 214, 215

Ammeters, iv, 279-80, vii, 165-72, 361;
automobile, 121;
galvanometers as, 179;
hot-wire, 163-4

Ammonia, viii, 68-70;
amines from, 215;
atmospheric, i, 11, 13, ix, 269;
boiling and freezing points, iv, 173;
critical temperature and pressure, 173;
density of, 113;
discovery, xvi, 120;
Gay-Lussac's studies, 133;
in explosives, viii, 74, 75, 253;
in fertilizers, 147, 253;
in ice-making, v, 357, 358, 380, viii, 69, 70;
in nitrogen cycle, 73;
in sweat, ix, 276;
metal test, viii, 288-9;
name, 98;
production, natural and artificial, i, 13, 35, 36, 153, viii, 46, 47,
68, 74, 75, 252, 253, 276, 278, xvi, 165;
production and disposition in body, ix, 284-5, x, 279-80;
refrigeration by, iv, 174, 187-8, viii, 69-70;
solubility, 111

Ammonia Water, viii, 68, 147

Ammonites, iii, 275, xii, 75

Ammonium, viii, 93, 147;
test for, 287, 289

Ammonium Compounds, viii, 147;
carbonate, 137;
hydroxide, 70, 121, 147, 288;
nitrite, 121;
salts, 147, 280;
sulphide, 289

Amorphous, defined, viii, 374

Ampère, A. M., vi, 20-1;
current unit named for, iv, 278;
rule of magnetic deflection, 275

Ampere, electric current unit, iv, 278, 284, vi, 69, 70, vii, 361
(see also Electric Currents, Ohm's Law)

Ampere-turns, iv, 288, vii, 362

Amphibians, iii, 285, xii, 167-81;
age of, iii, 20;
first appearance of, xv, 71;
in oceanic islands, xiv, 278;
relations to fishes and reptiles, iii, 284, 286, xii, 165, 183

Amphibole, iii, 321-3

Amphitheatres, mountain, iii, 66

Amphoteric, meaning, viii, 352

Amundsen, Capt., aeroplanes of, i, 46

Amyl Acetate, viii, 221

Amyl Alcohol, viii, 210, 214, 249

Amylases, viii, 357, x, 326

Amyloid, viii, 255

Anacondas, (boas), xii, 216

Anadromous Fishes, xii, 155

Anaërobic Bacteria, in peat production, xiii, 313;
in sewage treatment, viii, 328

Analytical Chemistry, viii, 285-95

Analyzers, crystal, iv, 354

Anamnesis, x, 370

Anaphylaxis, x, 212-15, 223

Anatomy, Chinese systems of, x, 13;
development of science of, 24, 30, 41-2, 44-5, 49, 51-2, 81, 116, 117,
xvi, 82-3, 179-80

Anaxagoras, on origin of earth, ii, 366-7;
theory of matter, xvi, 83, 118

Anaximander, theory of universe, ii, 367, xvi, 77-8

Anaximenes, theory of universe, ii, 366-7, xvi, 79

Andes Lightning, i, 149

Andes Mountains, glaciers of, xiv, 54;
impassability, 250;
lightning, i, 149;
mineral wealth, xiv, 237;
rivers, 167;
snow pinnacles, i, 116-17;
upraised in Cretaceous Period, iii, 219;
volcanoes, xiv, 315;
youthfulness of, 96, 235

Andrews, Thomas, i, 29, xvi, 175

Andromeda, nebula in, ii, 135-6, 136-7, 357, 361;
new stars in nebula, 332-3

Anel, Dominique, x, 90-1

Anemia, x, 337;
blood transfusion in, 338;
cause and effects, xi, 370-1;
of adolescence, x, 237;
pernicious, discovery of, 112

Anemograms, i, 295, 366

Anemometers, i, 83-4, 366;
for gusts, 295

Aneroid Barometer, i, 71, 72, 366, iv, 123-4, 381

Anesthetics, discovery and use in surgery, x, 123-5, 148, xvi, 180, 185;
effect on impulses, xi, 20;
Hindu use of, x, 13;
medieval, 41

Aneurisms, x, 28 note;
formation and rupture of, 336;
treatment of, 28, 91-2

Angel Fish, xii, 164

Anger, xi, 139, 141;
basic causes of, ix, 153, 166;
expression of, by monkeys, xv, 64;
in various sentiments, xi, 146, 148, 149, 150;
pain and, 120;
physical accompaniments of, ix, 240-1;
self-forgetfulness in, xi, 134

Angiosperms, xiii, 175-9;
alternation of generations in, xvi, 166;
first appearance and spread, iii, 256-7, xiii, 317-18

Anglers, (fish) eyes of, xii, 138;
"lure" of, 133

Angleworms, xii, 51-3;
power of distinguishing light, ix, 105

Anglo-Saxon Language, xv, 156-7

Anglo-Saxons, in Nordic group, xvi, 48;
use of tea, xiii, 229

Angular Diameters of Stars, ii, 150-1;
measurement of, 322-3

Anhydride, defined, viii, 374

Aniline, viii, 52, 237

Aniline Dyes, xvi, 163;
fluorescence of, iv, 379

Animalculæ, (see Unicellular Animals)

Animal Electricity, vi, 16, 17, 19, 23, 64
(see also Electric Fishes)

Animal Fats, viii, 246 (see Fats)

Animal Kingdom, classification, iii, 259-60, xii, 25-9;
how distinguished, viii, 349, xii, 14, 15, xiii, 13, 14;
relations to vegetable, viii, 334

Animal Protein, ix, 279, 280
(see also Proteins)

Animals, xii, 270;
activities of, ix, 20-1;
adaptation to environment, v, 16-18, 24, xvi, 152;
admiration unfelt by, xi, 146;
æsthetic emotions, xvi, 145-6;
anaphylaxis in, x, 212, 213, 214;
appendix uses in, xv, 56;
appetite in, ix, 88;
arctic, in mountains, xiv, 376-7;
artificial heat use by, ix, 308, xv, 229-30;
body heat regulation in, ix, 307, 308, 311;
brain in, xv, 62-3;
cannibalism in, ix, 280-1;
care of skin and coverings by, x, 310;
care of young, xv, 275-6;
carnivorous, xii, 332-65;
cell structure, 25;
chemistry of body and nutrition, viii, 348-70;
chromosomes in different species, ix, 46;
classification, xii, 25-9;
climatic influences, xvi, 141;
climatic limitations, xiv, 363-64;
cold-blooded (see Cold-blooded Animals);
communication means, xv, 140-1;
courtship of, 274-5;
differences of protoplasm in, ix, 278-9;
direction perception by, 117;
differences of complexity in, 48-50;
diseases of, x, 206;
distribution facilitated by land arrangement, xiv, 21;
domestication of, xv, 197-8;
ear movements in, ix, 82, 117;
educability of, xv, 66;
embryological development, 54-5;
evolution, Anaximander on, xvi, 78-9;
experience, profiting by, ix, 139, 152, xv, 66;
expressions of emotions by, 63-5;
face and brain case in, 43;
fear in various, xi, 136;
fear and anger effects, ix, 166;
flesh of, as food, 24, 284-6, xv, 333-4;
foods of, viii, 349, 350, ix, 24, 29, 30;
food procuring by, 18-20, 73-4;
geological history, iii, 12, 259, 306;
grasping ability of, ix, 67, 68, 82;
growth of, on what dependent, 287-9;
hair erection in, 161, 166;
heredity in, x, 231-2;
hoofed, xii, 300-31;
hunger and thirst senses in, ix, 87;
hunting and trapping of, xv, 222-7, 227-8;
hypertrophy of heart in, x, 331-2;
imagination in, xi, 224;
imitation in, xv, 66;
impulses instinctive, 273;
instincts of, 65-6;
land (see Land Animals);
later than plants, xiii, 298;
Latin names, xii, 28-9;
leadership among, xv, 361;
light and darkness effects on, x, 253;
locomotion, v, 215, ix, 73-4;
luminous, i, 346-7;
man's lessons from, xv, 206, 208, 220;
man's relation to, 53, 68;
marine (see Marine Animals);
"moral standards" applied to, xii, 351;
mutation in, ix, 342;
nitrogen uses, viii, 73;
of continental islands, xiv, 271;
of oceanic islands, 277-8;
oldest known remains, iii, 238, (Pl. 13);
physiology of, remarks on, ix, 305;
plants and interrelations, viii, 334, 335, 347, 349, 350, xiii, 82;
power development in, ix, 15, 16, 17, 18;
protective devices, xv, 16-18;
qualities, studies of, xvi, 143;
rate of increase, xv, 19-21;
reason in, xi, 243-4, xv, 67-8;
reflex actions in, 65;
regulatory mechanism in, x, 249-50;
reproduction from cells, 228, xvi, 155-6;
salts in body fluids, ix, 175-6;
seasonal phenomena, i, 254, 256;
seed dispersal by, xiii, 55, 58, 340, 343;
sense of sight in, ix, 105;
sense of smell in, 96-7, xi, 82;
sex relations among, xv, 274, 276-7;
smelling motions in, ix, 82-3;
struggle for existence among, xv, 21-2;
tool-using by, v, 9-11, x, 67-8;
touch sense in, 91;
unicellular, (see Unicellular Animals);
useful, xii, 324-31;
variation in, xv, 22-3 (see Variation);
vitamine needs and stores, x, 256-60;
warm and cold blooded, ix, 305;
water scarcity effects, 37-8;
wild, xii, 332-65;
young, metabolism in, ix, 38-9

Animal Starch, viii, 350

Animal Worship, xv, 333-4, 340-1

Animists, Animist Theory, x, 84-5

Anion, defined, iv, 381

Annuals (plants), xiv, 367;
garden species, xiii, 289, 297;
life of, 53, 152;
roots of, 15, 16

Anoa, of Celebes, xii, 330

Anode, defined, iv, 317, 381, vii, 251, 362;
first defined by Faraday, vi, 23

Antarctica, blizzards of, i, 133;
coal deposits, 199;
extent and elevation, xiv, 20, 22, 26;
former connection with S. America, 290;
glaciers of, 55;
island or continent, 23;
plateau, 222;
penguins of, xii, 251;
rainlessness, i, 109;
uninhabitability, xiv, 21;
winds of, i, 128-9

Antarctic Ice Sheet, iii, 62, 237

Antarctic Ocean, current of, xiv, 299, 305;
extent of, 22-3;
sea elephant of, xii, 335;
whales of, 298

Antares, angular diameter, ii, 151, 322-3;
color, 297;
former name, 302;
gaseous state, 382;
type III star, 115

Anteaters, xii, 281-3;
banded, 274;
scales of, xv, 220-1;
spiny, xii, 272-3

Antecedent Rivers, xiv, 164-70, 174

Antelopes, xii, 326-8;
fear in, xi, 136;
hunting of, with cheetah, xii, 365;
pronghorn, 322-3

Antennæ, of insects, xii, 100-1

Antennæ (wireless), iv, 314, vii, 261;
construction, 264-5;
effective resistance, 298;
fundamental wave-lengths, 266, 294;
of receiving stations, 267;
types, 295-6

Antenna Circuit, vii, 263-7;
energy dissipation, 297-8;
inductance and capacitance, 294-5, 296-7;
radiation, on what dependent, 298

Anthelion, i, 366;
oblique arcs of, 378

Antheridia, xiii, 158, 159, 161

Anthers, of flowers, xiii, 45, 118, 119

Anthracene, viii, 240, 253

Anthracite Coal, iii, 344;
beds in U. S., 347-8;
constituents, 345, viii, 44;
graphitic, iii, 345;
lessening supply, 346;
loss of heat with, v, 155
(see also Hard Coal)

Anthrax, Koch's studies of, x, 149;
Pasteur's work on, 140-2

Anthropoid Apes, xii, 381-4;
primates, 373;
susceptibility to human diseases, x, 206

ANTHROPOLOGY, Volume xv, defined, xv, 10, 11, 15, xvi, 36, 47;
daily interest, 26, 29

Antibodies, x, 205, 216

Anticathode, defined, iv, 381

Antichlor, viii, 140

Anticline, defined, iii, 377;
illustrated, 85, 128 (Plate 7), xiv, 95

Anticrepuscular Rays, i, 169, 366

Anticyclones, i, 134-5, 366, xiv, 349, 350;
Siberian, i, 218

Antigens, x, 205, 217

Antimony, affinity strength, viii, 128;
atomic weight and symbol, 383;
expansion on solidifying, iv, 150;
fusibility, viii, 384;
ores, 198, 270;
specific gravity, 384;
tests, 287-8;
uses in industry, 169;
use of, in medicine, x, 12, 50, 169

Antinodal Current, vii, 297

Antinori, Luigi, i, 213

Antiseptics, viii, 332-3;
Carrel-Dakin solutions, x, 181-3, 382;
discovery, 40, 145-6, xvi, 180, 182-3

Antiseptic Surgery, x, 146-7;
history of development of, 40, 55, 145-6, 381-2, xvi, 108, 114, 182-4;
in World War, x, 181-3, 381-2

Antitoxins, x, 218, 296-8;
of diphtheria, 197, 212, 213-14, 218, 296-8;
of tetanus, 218, 299

Antitrade Winds, i, 366, xiv, 348

Anti-twilight Arch, i, 167, 366

Antlers, xii, 316, 317, 319

Ant Lions, xii, 106

Antony, Mark, speech on Cæsar, xi, 331

Ants, aphids of, xii, 101;
appearance in Triassic, 104;
nest repairing by larvæ, v, 10;
numbers in tropics, xii, 282;
"showers" of, i, 357;
social habits, xii, 124, 125, 126;
underground rooms of, xv, 266

Antwerp bombardment, audibility, i, 191;
harbor of, xiv, 270

Antyllus, x, 28

Anuria, x, 344-5

Aorta, ix, 196, 201 (fig.), x, 334;
elasticity of, ix, 210;
ligation of, x, 129-30

Aoudad, xii, 326

Apatite, iii, 323, viii, 193

Apes, anthropoid, xii, 381-4;
black of Celebes, 379;
brain of, xv, 62, 90-1;
embryological development, 54-5;
imitation in, 66;
manlike, iii, 301-3, xv, 88-95;
man's relation to, xv, 56-7;
nostrils of, xii, 376, xv, 46;
physical comparison of, with man, iii, 301, (fig.), xv, 57-62;
reasoning power, 67-8;
sex relations among, 277-8;
skull capacity, xv, 89;
skull shape, 42-3;
tigers and, xii, 362;
tool-using by, v, 9;
working methods, xv, 58

Aphids, xii, 118;
ants and, 101

Aphis Lions, xii, 106

Aphrodite (sea mouse), xii, 54

Apian, Peter, ii, 41;
comet of, 85

Aplysia, xii, 68

Apollonius of Perga, ii, 31, xvi, 90

Appalachia, iii, 195, 205, 210

Appalachian Mountains, antiquity of, xiv, 96, 235;
Catskill formation, iii, 195;
coal beds, iii, 346-7, 204, xiv, 237;
folding intensity, iii, 86, xiv, 36, 230;
forests, xiv, 372;
former elk of, xii, 317;
geological history, iii, 130, 132-4, 135-6, 140, 191, 205-7, 210, 219,
xiv, 97-8, 168-9, 228-9, 235-6;
"grain" of, xiv, 99;
historical rôle, 191, 194, 242-3, 249;
igneous formations absent, 228, 230, 234;
iron deposits, iii, 358-9;
length and breadth, xiv, 36-7, 227;
limestone soils, iii, 27;
marble production, 371;
metallic ores of, xiv, 237;
non-marine deposits in trough, iii, 209-10, 214;
petroleum fields, 350;
plateau west of, xiv, 221;
present relief, origin, iii, 231-2;
ridges and valleys, 36, 137, 233-4, xiv, 94, 97-8, 234, 236;
rivers across, iii, 36, 137, 233, xiv, 166-7, 168-9, 180-2;
site formerly submerged, iii, 12, 130, 168, 181, 184, 187, 194-5, 197,
198;
springs, thermal and mineral, 128, xiv, 143;
strata, thickness and composition, iii, 132, 180, xiv, 228-9;
strata of various periods, iii, 184, 187, 195-6, 203;
stream capture in, xiv, 180-2;
thrust faults, iii, 90;
typical range, xiv, 226;
wind and water gaps, iii, 39, xiv, 58, 98, 169

Appalachian Revolution, iii, 205, 208, 210

Appalachian System, xiv, 227

Appalachian Valley, xiv, 167

Appendicitis, asepsis in, x, 147;
cause of, 224

Appendix, ix, 233 (fig.);
as infection center, x, 220;
in man and animals, xv, 56

Appetite, ix, 87-8, 299;
exercise effects, x, 303-4

Apples, acids of, viii, 223;
development of, xiii, 54;
food value, viii, 365, ix, 250-1, 299, x, 268

Apple Tree, family, xiii, 197-8;
origin, 224;
petal arrangement, 190

Apteryx, xii, 249

Aquamarine, iii, 325

Aqua Regia, viii, 174

Aquatic Animals, mental inertness of, xii, 140,
(see also Crustaceans, Mollusks, Naids, Polyps)

Aquatic Plants, first on earth, xiii, 300, 301, 303;
fertilization, 123, 149-52;
fossils, 303;
in lakes, xiv, 210

Arabia, animals of, xii, 249, 327, 342, 344, 359;
Danish scientific expedition, xvi, 123;
plains of, xiv, 217;
source of coffee, xiii, 231, 283

Arabian Horses, xii, 307

Arabian Language, xv, 162;
words from, in English, 161

Arabic Numerals, xv, 184, xvi, 62, 103

Arabs astronomy of, ii, 11, 36-9, 302, xvi, 100;
bananas known to, xiii, 216;
mathematical advances, ii, 12, xvi, 54, 103;
medical science of, x, 31-3, 36, 37-8, 39, 40, 100;
sciences of, xvi, 54, 100;
sugar introduced by, xiii, 215

Arago, discovery of magnetism of rotation, vi, 21;
lightning studies, i, 146

Aral, Sea of, depression of, xiv, 203;
shallowness and salinity, 206-7;
size of, 204

Arapaima Fish, xii, 154

Arara Cockatoo, v, 9-10

Arcadian Range, xiv, 227

Arcathagus, x, 25

Arc Furnaces, vii, 303

Arc Generators, vii, 291

Archæopteryx, xii, 239-41

Archegonia, xiii, 158, 159, 161

Archeozoic Era, iii, 164-75;
life in, 262, 263, 265, xv, 71

Archeozoic Rocks, iii, 164-74;
graphite found in, 249-50;
iron ores in, 358

Arches, false and true, xv, 268-9;
weak in earthquakes, xiv, 342

Archimedes, iv, 25, 26;
mathematical and other work, xvi, 89, 90;
principle of, iv, 30, 102-5, 107;
screw of, 26-7 (fig.)

Arc Lamp, Arc Light, iv, 310-11, 352, vi, 279, 280-3;
Bunsen's carbon rods, xvi, 189;
compared with sun, ii, 169;
Davy's experiment with, vi, 19;
direct and alternating currents on, vi, 332, vii, 208-9;
graphite electrodes, vii, 300, 308

Arc Process, i, 36, vii, 323-4

Arcs of Lowitz, i, 366

Arctic Archipelago, xiv, 20

Arctic Current, xiv, 304-5

Arctic Ocean, copepods of, xii, 84;
depths, xiv, 22;
enclosed character, 22, 290, 299

Arctic Plants, in mountains, xiii, 321, xiv, 365-6, 376-7

Arctic Regions, conditions of life in, xv, 123-4;
forests of Coal Age, xiii, 307;
frozen soil of, xiv, 75;
growing season in, 375;
plant conditions in, 365;
seals of, xii, 335;
skin canoes of, xv, 264;
snow line in, 72-3;
wolves of, xii, 340-1;
winds, i, 127, 128
(see also Polar Regions)

Arcturus, angular diameter, ii, 151;
decreasing distance, 120;
displacement lines in spectrum, 119;
gaseous state, 382;
origin of name, 302;
parallax, 316;
"solar" star, 115

Arequipa Observatory, ii, 145-6

Arethusa (plant), xiii, 186 (fig.)

Argentina, ancient sloths of, xii, 283;
hail rods, i, 343;
pampas of, (see Pampas);
stock-raising, xiv, 384;
weather service, i, 228-9 (note), ii, 186-7;
wheat cultivation, xiii, 211

Argon, discovery and character, i, 10, 11, 12, viii, 67, 181, 309;
electric lamp filler, i, 33;
periodic classification, viii, 182-3;
symbol and atomic weight, 383

Argonauts, (shellfish), xii, 77-8

Argonne Forest, xiv, 91

Arid Regions, alkali deposits, viii, 139;
dust whirls, i, 60;
mineral matter in waters, viii, 196;
plants of, xv, 18-9;
rainfall of, i, 109, 112;
rock weathering in, xiv, 41-2, 51-2, 77-9, 124;
soils of, 68-9, 383
(see also Deserts)

Aristarchus of Samos, ii, 10, 27-8

Aristillus, ii, 28-9, 31

Aristocracy, changing ideas of, xv, 377

Aristocratic Type, xiii, 356

Aristotle, association principles, xi, 197-8;
authority in Middle Ages, ii, 33, 42;
conception of cosmos, ii, 367;
lectures on fossils, etc., xvi, 168;
medical work of, x, 23, 27, 74;
meteorological treatise, i, 67;
monad theory, xvi, 118;
on falling bodies, ii, 53;
on knowledge and perceptions, xvi, 87;
on Mars, ii, 227;
on origin of earth, xvi, 78;
on shooting stars, ii, 283;
scientific methods, xvi, 88-9;
syllogism invention, 88;
zoölogical work, 126

Arizona, arid topography, xiv, 42;
cactus plants, xiii, 28, 106-7;
chapparal of, xiv, 379;
cliff lines of, 88;
climate of plateau, 222;
copper mines, iii, 360;
faults at Bisbee, 90;
forests of, xiv, 220-1, 373-4;
Gila monster of, xii, 204, 207;
mesas, xiv, 82;
sunniest state, i, 86;
timber limits, xiv, 373;
volcanic fields of, 102, 315, 317, 318

Arkansas, aluminum production, iii, 369;
hot springs of, xiv, 143, 144;
malaria campaign in, x, 173-4

Arkwright, Richard, v, 274, 376

Armadillos, xii, 282, 283-4;
scales of, xv, 220

Armature Reaction, vi, 190, vii, 145-6

Armatures of Dynamos, iv, 307, vi, 176, vii, 362;
of direct current generators, vi, 178, 179-86;
of alternators, 196, 197-8, 202, 205, 207, 210, 212-13

Armatures of Magnets, iv, 250, vi, 30 (fig.), vii, 362;
uses of, iv, 291-2

Armatures of Motors, vi, 223, 224-5, 235-6

Armies, crowd psychology in, xi, 326-7;
fatigue in retreat, 275

Armor, development of, xv, 220-1

Armored Cable Wiring, vii, 61-2, 362

Armor Fishes, iii, 281, 282, 284

Armorican Range, xiv, 96, 235

Armor Plate, making of, v, 323, 382

Arms, arteries of, ix, 196-7;
bones of, 67-8, (fig.), 77, (fig.);
bones, growth of, 58;
equal length of, 169-70;
freedom of movement of, 66;
grasping organs, 82;
length as yard measure, iv, 45;
length in man and apes, xv, 57, 59;
muscles of, ix, 76-7

Arnold of Villanova, x, 41

Aromatic Hydrocarbons, viii, 232-6, 374

Arrack, from coco palm, xv, 125;
Indian, xiii, 213

Arrhenius, on Martian life, ii, 248 on osmotic pressure, xvi, 164;
theory of life, xii, 9

Arrows, development, and use of, xv, 213-16;
Indian, 196 (fig.)

Arsenic, affinity strength, viii, 128;
atomic weight and symbol, 383;
in copper ore, vii, 320;
ores of, viii, 198, 270;
properties, 169;
specific gravity, 384;
tests for, 201, 287, 288

Art, primitive types of, xv, 110-21;
science and, iv, 9

Arterial Blood, ix, 260, 263, 264

Arterial Pressure, ix, 213-14, x, 334

Arteries, ix, 191, 196-7, x, 334;
bleeding from, discovery of, 39;
caliber changes in small, ix, 215;
connection with veins, 192-3 (fig.), 197;
elasticity of, 59, 210-12, 213-14;
former ideas of, x, 62, 63, 65, xvi, 106;
hardening of, x, 334-6;
ligating of, 56, 96;
"man as old as," ix, 214, x, 335;
passage of blood along, ix, 211-12;
systole and diastole of, x, 62, 63-4, 65

Artesian Wells, iii, 118-19, xiv, 138;
constancy of, 152;
of North Dakota, 12, 139;
warm water from, 144

Arthropods, iii, 260, 263, 264, 276-80, xii, 81, 126

Arthur's Seat, Scotland, xiv, 112

Artichokes, xiii, 206, 222

Artificial Ice, production, v, 349-50, 354-8, viii, 69, 70

Artificial Light, colors in, ix, 115;
gains from, iv, 51

Artificial Limbs, x, 190

Artillery, armor versus, v, 368;
distance audible, i, 188-9
(see also Guns, Projectiles)

Artillery Plant, xiii, 56

Arts, æsthetic, origin and development, xv, 296-325

Arts of Life, xv, 205-72

Arum, fertilization of wild, xiii, 153

Arum Family, xiii, 188;
flower arrangement, 52

Aryan Languages, xv, 161, 162, 163

Aryans, in Nordic group, xvi, 48;
of India, 53;
rule of fathers among, xv, 367

Asbestos, iii, 338

Ascension Island, xiv, 289

Ascidians, xii, 19, 20, 129

Asclepiades, x, 25-6

Asepsis, in surgery, x, 14, 134, 146-8;
Lister on, 144-5

Ash, viii, 374;
handling in power plants, vi, 356;
of coal, viii, 44, 45;
of plants, xiv, 65-6;
volcanic, 324

Ash Trees, for gardens, xiii, 271-2;
leaves, 36-7;
seed dispersal, 58, 343

Asia, animals of, xii, (herbivora), 302, 305, 313, 314, 317, 320, 327;
animals (carnivorous), 336, 339, 344, 345, 352, 356, 357, 365;
birds of, 263;
climate changes, results, iii, 75, xiv, 361-2, xvi, 141;
climate of eastern, xiv, 345;
crocodiles of, xii, 201;
drainage system, xiv, 190, 195-6;
earthquake belts, 331-2;
eastern coast, 248-64;
faulted topography of eastern, 124-5;
food plant regions, xiii, 221;
forests, xiv, 369-77;
formerly united with America, xii, 313, xiii, 351, xiv, 30;
geological history, iii, 216, 235-6;
grasslands and deserts, xiv, 381;
monsoon countries, conditions in, 359-60;
plains, 217;
plants common with America, xiii, 351;
plateaus and mountains, xiv, 217-22;
rodents of, xii, 287-9;
rubber production, xiii, 248;
salt lakes, viii, 139;
snails of, xii, 69;
snakes of, 218, 226, 229, 231, 232;
terrestrial leeches, 55-6;
trees of eastern, xiv, 377;
vegetables and fruits originating in, xiii, 222-7;
volcanic fields, xiv, 316-18;
wind types, i, 131, 134, 136

Asia, Central (see Central Asia)

Asia Minor, climate changes in, xiv, 361-2;
plateau of, 222

Asiatic Volcanic Belt, xiv, 316

Asparagus, effects on urine, ix, 274-5;
green food, 27;
origin, xiii, 222;
stem of, 30

Asps, xii, 230

Assam Earthquake, iii, 98, xiv, 334

Asses, xii, 308

Association of Ideas, ix, 150-1, xi, 197-207;
in language, ix, 151-2;
memory and, 149-50;
in imagination, xi, 219-20, 209, 212, 216-17;
necessary to attention, 232-3, 234;
normal and abnormal complexes, x, 355

Assyria, civilization conditions, xv, 127;
art of, 301;
cuneiform writing, 175 (fig.);
history and civilization, xvi, 51-3;
skin rafts of, xv, 264;
sun-worship and astrology, ii, 20-1

Assyrian Language, xv, 162

Asteroids, discovery, ii, 254-7;
in solar system, 163-4;
life on, 248;
origin, 258, 371, 373, 374;
photographic study, 131-2;
size, shapes, and orbits, 162, 257-8

Asthma, bronchial, ix, 162, x, 223;
from adenoids, 342

Astigmatism, ix, 113-14, xi, 85

Astonishment, and fear, xi, 131

Astraphobia, i, 330-66

Astrolabes, ii, 11, 29, 34, 46-7, 93

Astrology, astronomy and, ii, 9, 20;
history in various countries, ii, 20-1, 23, 37, xvi, 58;
medical progress and, x, 14

Astronomical Instruments, Bessel on, ii, 93;
development of, 10, 11, 12-13, 13-14, 16, 161

Astronomical Photography, ii, 125-38;
in corona studies, 221-2, 225;
in parallax work, 314;
in nebular studies, 358;
telescopes used in, iv, 372-3

Astronomy, daily interest of, xvi, 12;
defined, 37;
exact science, x, 368;
history of, ii, 9-92, iv, 19, xvi, 56-8, 61, 69, 70, 81-2, 90-1, 100,
101, 102, 103, 124-5;
mathematical and descriptive, ii, 15, 16;
meteorology and, i, 7;
new and old, ii, 113-14;
personal measurements in, xi, 155-6;
spherical, ii, 29

Astronomy Today, Volume ii

Athletes, "form" in, ix, 159

Athletic Contests, value to spectators, xi, 139-40

Atlantic Cables, laying of first, vi, 24;
Telegraph Plateau and, xiv, 288

Atlantic Coast, shoal-water belt, xiv, 25, 285

Atlantic Coastal Plain, xiv, 213-14;
artesian wells in, iii, 119;
forests, xiii, 371, xiv, 372-3;
geological history, iii, 212-13, 216, 221, 231;
soils and agriculture of, xiv, 218-19

Atlantic Drainage System, xiv, 189-90

Atlantic Ocean, airship flights across, iv, 107, v, 228-30, 233;
birds of, xii, 251, 252, 253;
climates on opposite coasts, xiv, 345, 346-7;
clipper's time across, v, 188;
conformation of floor, xiv, 288-90;
coral reefs in, 264;
depths, iii, 51;
extent of, xiv, 22;
first steamship, v, 192-3, 378;
herring fisheries, xii, 156;
oceanic islands of, xiv, 277;
salt in, viii, 139;
temperature of water, xiv, 14, 297;
trade winds, i, 127, 130;
tree corals of, xii, 43;
unchanged for ages, iii, 55;
weather charts, i, 276;
wireless weather reports, 280
(see also North Atlantic)

Atlantic Seaboard, rainfall, i, 112;
super-electric zone, vi, 384

Atlantic Type of Coasts, xiv, 247, 249-50

Atlantic Volcanic Belt, xiv, 316

Atmometers, i, 88-9, 366

Atmosphere, anatomy of, i, 9-23;
circulation (winds and storms), 123-40, xiv, 347-51;
composition (gases), 9-16, viii, 66-8, 152;
dense, effects of, iv, 31-2;
density decrease upward, i, 16, 17, 171, 173, 303, iv, 108, 124, ix,
267-8, xiv, 354;
density irregularities, optical effects, i, 171-2;
disease germs in, 325-6;
dust and smoke in, 52-65, 325, vii, 216-17, ix, 269;
effect on colors of stars, ii, 296;
effect on meteors, 283, 285, 290;
effect on sunlight and colors, i, 165-6, 167-71;
electrification, 144, 145, 146, 150, vii, 207, 212-13, 216-17;
heat absorption by, iv, 194;
heating of, by sun, i, 123;
heat retention by, ii, 244, 382, iv, 183-4;
height, i, 16-18, ii, 244, iv, 116;
highway, i, 39-51;
layers (see Stratosphere, Troposphere);
light of, 164;
magnifying of, by telescopes, ii, 98, 140, 141;
meteorology, science of, i, 7;
nitrogen fixation from (see Nitrogen Fixation);
oxygen in upper, ix, 267-8;
radioactive emanations in, i, 143;
resources in, 24-38;
theories of origin, iii, 160, 163;
topographical work of, xiv, 62-79;
weight, i, 23, ii, 279, v, 222-30
(see also Air)

Atmosphere (unit of pressure), iv, 121, 123, 381, viii, 107

Atmospheric Acoustics, i, 186-96

Atmospheric Electricity, i, 141-63, vii, 201-19, 362;
in climatology, i, 211;
physiological effects, 330

Atmospheric Engine, Newcomen's, v, 144

Atmospheric Optics, i, 164-85, iv, 327-9

Atmospheric Pressure, amount and direction, i, 23, ii, 244, iv, 116-23,
v, 222, viii, 107;
amount at different elevations, iv, 124;
body regulation to, x, 250;
boiling point and, iv, 170, viii, 303;
discovery of, iv, 114-16, 132, v, 112;
early experiments with, iv, 29-30;
equalization in ear, ix, 102;
isobars, i, 125-26;
life in relation to, ii, 245-48, xi, 53;
measurement, i, 70-2, iv, 120, 121, 123, 124;
physiological effect of changes, i, 303, 327-9;
stratosphere in relation to, 20;
unit of, iv, 121, 123, 381, viii, 107;
variations with temperature, iv, 121-3, 124-5;
weather and, i, 70, 237-8, 241-2
(see also Pressure Areas);
winds in relation to, 124, 125-6, 127-9, 134-5;
work done by, 25, v, 112-15, 137-8

Atmospheric Refraction, i, 167-74, 380, iv, 327-30;
early studies of, ii, 32, 41

Atolls, xii, 41

Atomic Energy, ii, 384, v, 181, viii, 186-7

Atomic Numbers, viii, 183, 309

Atomic Theory, history and deductions, viii, 110;
in Greek philosophy, xvi, 83-4, 87, 118;
Leibnitz's, 117-18

Atomic Volume, determination, viii, 307

Atomic Weights, viii, 92, 383;
chemical calculations by, 96;
classification of elements by, viii, 177-83, 189, xvi, 163;
determination of, viii, 306-7;
hydrogen basis, 33;
introduction, xvi, 134;
physical state and, viii, 297-8;
properties dependent on, xvi, 134;
radioactivity and, viii, 184, 185-6, 188;
regular increase in similar elements, 132, 176, 179;
specific gravity and, 313;
specific heat and, 308-9;
table, vii, 384, viii, 383

Atomists, school of, xvi, 84-6

Atoms, viii, 25-7;
asymmetric, 309-10;
chromophor groups, 258;
defined, iv, 21, vi, 110-11, viii, 374;
vii, 362, disintegration, 185-7, 188;
dissociated, in ball lightning, vii, 214-15;
electrification, vi, 122-3;
energy of (see Atomic Energy);
Greek theory, xvi, 118;
laws involving, viii, 110;
Leibnitz on, xvi, 118;
magnetic fields of, vi, 117;
motion within, viii, 309-10;
of body, Epicurean theory, x, 26;
size, vi, 112-13, 115;
stability, vii, 215;
structure of, iv, 23, 55, vi, 113-15, 120-1, viii, 187-9, 307;
unchangeableness, 175-6

Attention, xi, 228-36;
habit and, 253-5;
methods of arousing, in advertising, 344-8;
ordinary meaning, 40

Attraction, scientific meaning, vii, 362, iv, 96

Audibility, distances and variations, i, 187-92;
vibration limits of, iv, 204, ix, 99

Audion, iv, 315-16, vi, 339 (fig.), vii, 279, xvi, 191-2
(see also
Vacuum Tube)

Auditoriums, acoustic qualities, iv, 239;
cooling system, 188;
echoes in, 238