=Acid=, carbonic, what it is, 509
=Aerial=, on ship, (illus.), 455
=Aeroplanes=, English Channel crossing (illus.), 132
Curtiss biplane (illus.), 131
first demonstrations of, 130
first flight in Europe, 129
first man-carrying (illus.), 128
first successful (illus.), 126
gas motors used in, 130
gliding, 137
greatest present value of, 136
records of, 131
red wing (illus.), 131
what two brothers accomplished for, 130
Wright Bros.’ inventions, 130
=Age=, why do we, 196
=Air=, does it move with the earth? 400
does it weigh anything? 398
dust in, 38
extend, how far does, 243
=Airlocks=, description of in tunnel building, 213
=Ammunition=, first invention of, 40
fixed, 47
in prehistoric times, 40
=Animals=, can they think? 194
is man an, 180
that leap greatest distance, 122
which foretell weather, 240
=Anthracite seams= (illus.), 260
=Aqueduct= (illus.), 505
=Are= matches poisonous, 294
=Armor=, in the Middle Ages, 44
=Army=, wireless in the, 448-451
=Are= there two sides to the rainbow? 254
=Arrow=, what causes it to fly? 408
=At= what point does water boil? 220
=At= what rate does thought travel? 242
=Australian Ballot=, where first used, 122
=Automobile= (illus.), axle, location of, 186
beginning of, 183
carburetor, location of, 184
carburetor, use of, 184
chassis, complete, 188
cog-wheels, use of, 183
cog-wheels, location of (illus.), 183
crankcase, location of (illus.), 183
cylinder, location of (illus.), 184
drive shaft, location of (illus.), 187
electric generator, use of, 185
exhaust, 184
fenders, location of, 188
fenders, use of, 188
finished car (illus.), 189
first American (illus.), 189
fly-wheel, location of (illus.), 183
fly-wheel, use of, 183
frame (illus.), 186
gasoline, what it does, 183
gasoline tank, location of, 187
gears, location of (illus.), 183
gears, use of, 183
heart of (illus.), 184
how improved, 190
magneto, location of, 185
magneto, use of, 185
marvellous growth of twenty years, 189
modern power plant complete, 190
oil pan, use of, 184
oil pump, location of, 184
piston, location of (illus.), 183
piston, use of, 183
power plant, an (illus.), 185
radiator, location of (illus.), 188
radiator, use of, 188
ready for the wheels, 187
second stage of construction (illus.), 186
self-starter, location of, 185
self starter, use of, 185
Smithsonian exhibit of complete power plant, 190
springs, location of (illus.), 186
springs, use of, 186
steering gear, location of (illus.), 187
street scene 20 years ago, 189
transmission, location of, 186
tire pump, use of, 185
tires, how made, 382
transmission, use of, 186
water pump, location of, 185
water pump, use of, 185
what the completed chassis looks like (illus.), 188
=Bacon, Roger=, discoverer of gunpowder, 44
=Balance=, effect of sunlight on, 37
=Baldness=, chief course of, 143
why some people are, 143
=Ball=, why it bounces, 63
bearings, what they are, 180
=Balloon=, what keeps it up, 199
why it goes up, 199
=Ballot=, when first used, 122
Australian, where first used, 122
=Bearings, Ball=, what they are, 180
=Bee=, how it lives, 336
why it has a sting, 336
=Bell, Alexander Graham= (illus.), 70
first telephone, 72
=Bend=, why things, 62
=Biplanes=, Curtiss (illus.), 131
in flight, Curtiss (illus.), 136
=Birds=, how do they find the old home? 408
how they learn to fly, 178
how they find their way, 407
reproduction of life in, 179
why do they sing? 408
=Birds’ Eggs=, why different colors, 233
=Blasting= gelatin, definition of, 206
=Bleriot, M.=, first European flights, 129
=Blotter=, capillary attraction of, 18
how it takes up ink, 18
=Blush=, why do we, 194
=Boat=, how it can sail under water, 269
hydroplane of submarine, 270
inside of a submarine (illus.), 272
=Bodies=, swiftest moving, 25
=Boiling= point of water, 220
what makes water, 220
=Boring mill= (illus.), 56
=Bottles=, gurgle in, 63
=Bounce=, why a ball will, 63
=Bow=, long (illus.), 42
=Bow-and-Arrow=, invention of, 43
=Boxes=, match, how made, 294
=Brazil, Emperor of=, receives first words over telephone, 74
=Bread=, how flour is made, 462
difference in Graham and whole wheat, 461
grinding wheat (illus.), 464
harvesting wheat, 460
loaves of world (illus.), 459
origin and meaning of, 460
purifying machine (illus.), 463
separating fibre germs (illus.), 463
wheat conditioning (illus.), 462
when wheat was first used in making, 461
where it comes from, 460
why so important, 460
=Break=, why things, 62
=Breech=, of a big gun, 53
=Breech-loaders= in Civil War, 48
in rifle, 47
=Brush=, in writing, invention of, 13
in writing (illus.), 13
=Bullets=, cupro-nickel used in, 50
grading of, 51
weighing of (illus.), 49
=Buildings=, concrete, how made (illus.), 100
=Buttons=, on sleeves, 64
=Building=, tallest in the world (illus.), 395-508
what holds it up? 496
=Building foundations=, construction of, 496
compressed air, use of (illus.), 500
cutting piles with a hot flame (illus.), 498
driving steel piles, 496
piles filled with concrete (illus.), 499
piles, length of, 497
piles, sinking of (illus.), 497
use of oxyacetylene, 498
=Cable, laying= armoring machine (illus.), 437
arrived on other side, 433
bulge (illus.), 437
gear-paying-out (illus.), 431
Great Eastern, the, 434, 437
landing of (illus.), 433
machinery on cable ship (illus.), 431
paying-out machine (illus.), 431
shore end of (illus.), 429
storing of, aboard ship (illus.), 430
what they look like when cut in two (illus.), 428
=Cable, ocean=, Continental Morse Code, 438
how dropped (illus.), 432
how repaired (illus.), 435
inventor of, 434
laid, how, 429
man who made it possible, 434
pioneers of, 434
signals as received (illus.), 438
what is it made of, 429
=Cable, repairing=, grapnels (illus.), 435
how repaired, 435
on rocky shore, (illus.), 438
powerful engines used (illus.), 436
splicing of (illus.), 436
=Cable, service=, map of Trans-Atlantic, 439
=Cable, vault=, of telephone (illus.), 67
=Cabriolet=, 122
=Cacao, beans=, bags of (illus.), 388
how cured, 392
nibs, 392
=Cacao=, flaked, how made, 392
how gathered, 391
pods, how gathered, 391
free, discovery of, 388
and chocolate, difference between, 389
=Cackling=, why a hen, 233
=Calibre= of a gun, 53
=Calico=, name, where from, 123
=Camera=, 22
first moving picture, 375
=Can= a bee sting? 536
=Can= animals think? 194
=Candles=, did they come before lamps? 294
why it burns, 21
why it gives light, 21
why you can blow out, 21-36
when introduced, 296
=Candy=, why do children like? 409
why does eating candy make some people fat? 409
=Carbon=, 352
=Carbonate of Soda=, used in developing, 23
=Carburetor=, in gas engine, 184
=Carpets=, carding machine (illus.), 170
dyeing the yarn, (illus.), 170
examining and repairing (illus.), 173
how yarn is dyed, 170
manufacture of (illus.), 169
modern, how made, 169
packing for shipment (illus.), 173
processes, 169-170-171, 173
stamping designs, 173
view of factory (illus.), 172
weaving, by machine (illus.), 171
wool, packing machine (illus.), 169
wool sorting, 170
=Cartridges=, invention of, 48
types of (illus.), 49
=Cave=, man who invented ammunition, 40
=Cement=, alumina in, 95
amount used in United States, 95
arch, 95
bagging (illus.), 99
bridges, 95
bucket (illus.), 97
burned (illus.), 98
calcined (illus.), 98
clay in, 95
crusher (illus.), 97
dams, 95
fireproof, 95
grinders (illus.), 98
industry, 95
in water, 95
kiln (illus.), 98
lime in, 95
machine (illus.), 97
marl in, 95
mill (illus.), 96-98
mixing (illus.), 99
mortar, 99
on farms, 95
origin, 95
plastic, 95
Portland, 95
powder (illus.), 98
quarry (illus.), 96
reinforced, 95
rock (illus.), 95-97
sewers, 95
shale in, 95
shovel (illus.), 96
sidewalks, 95
silica in, 95
strength of, 95
subways, 95
tunnels, 95
walls, 95
what is it, 95
what made of, 95
what used for, 95
weighing (illus.), 99
where obtained (illus.), 97
=Chalk=, where it comes from, 18
=Chattering=, why do my teeth, 218
=China-making=, blungers, 404
clay, in making dishes, 405
decorating cups (illus.), 404-406
dishes, how shaped, 405
glazing plates (illus.), 404
grinders (illus.), 404
how the dishes are shaped, 405
molding (illus.), 405
pressing water from clay (illus.), 405
pulverizing materials, 404
pulverizing mill (illus.), 404
saggers (illus.), 406
taking the dishes from kiln (illus.), 406
=Chinese=, probable discovers of gun powder, 44
=Chocolate=, broma, what it is, 390
cacao beans (illus.), 388
cacao pods, (illus.), 391
cacao tree, discovery of, 388
cocoa butter, 390
cocoa mill (illus.), 390
cocoa roaster (illus.), 390
cocoa shells, 390
cracking mill, 389
cream mixing (illus.), 393
difference between and cacao, 394
dipping department, 394
finisher (illus.), 392
flaked cocoa, 392
heating machine (illus.), 393
how are chocolate candies made? 394
how made, 392
making, 393
milk, how made, 394
mill (illus.), 392
mixer (illus.), 393
shell separator (illus.), 389
what cocoa butter is, 390
wrapping individual, 394
=Cigars=, how they are made, 517
=Clay=, what is, 495
=Circles=, tendency to walk in, 91
=Clinking= glasses, how it originated? 232
=Clock=, age of, 319
largest in the world (illus.), 321
machinery which runs a big (illus.), 322
in Independence Hall (illus.), 323
in New York City Hall, 323
=Cloth=, beaming (illus.), 89
Burling (illus.), 88
Burr picker, 87
chloride of aluminum in making, 98
English cap spinning (illus.), 89
finished, ready for market (illus.), 90
finish perching (illus.), 90
fulling (illus.), 90
how made from wool, 85
how made perfect, 83
how woolen is dyed, 87
mending perching (illus.), 88
napping, 89
piece dyeing (illus.), 90
ring twisting (illus.), 89
sulphuric acid solution in making, 87
teasel, 89
weaving and scouring (illus.), 88
web, 86
woolen mule spinning (illus.), 89
worsted carding (illus.), 85
yarn inspecting (illus.), 89
=Clothes=, cost of wool in a suit of, 83
of wool, 80
wool in one suit of, 83
=Coal=, anthracite, 257, 258
anthracite seams (illus.), 260
breaker (illus.), 257
cars ready to go to surface (illus.), 260
dangers to the miners, 262
electric cap lamp (illus.), 264
firedamp, 262
gas illuminating from, 299
gases, 262
history of the safety lamp (illus.), 263
how the miners loosen the coal (illus.), 261
how the slate pickers work (illus.), 259
lamp which saves many lives, 263
man who invented the safety lamp, 264
mine workers that never see day light, 258
mules and their drivers (illus.), 258
peat, 262
safety lamp and firedamp, 262
seams (illus.), 260
shaft gate (illus.), 260
slate pickers (illus.), 259
soft, 259
spiral slate pickers (illus.), 259
stable underground (illus.), 258
undercutting with compressed air machines (illus.), 261
undercutting with pick (illus.), 261
=Cocoa=, see Cacao
=Cocoon=, description of, 115
completed (illus.), 116
from which moths have emerged (illus.), 117
how silk is reeled from, 118
moths emerging from (illus.), 117
number required to one pound of silk, 117
silkworm beginning of (illus.), 116
silkworm, preparing for making of (illus.), 116
=Coins=, gold, 266
in glass of water, 38
silver, 266
=Cohesion=, definition of, 219, 220
=Cold=, why some things are, 144
=Color=, exposed to light rays, 36
in paint, 229
what it is, 123
=Colors=, different in birds’ eggs, 233
in sunset, cause of, 253
=Color=, of rainbow, 253
red, why it makes a bull angry, 490
=Columbus=, brought first sheep to America, 80
=Comb honey=, development of (illus.), 529
=Compounds=, compared with elements, 349
=Compressed air=, method in building tunnels, 211
=Concrete=, buildings (illus.), 100
construction (illus.), 100
decay, 101
engineering, 102
forms (illus.), 100
houses (illus.), 101
loads (illus.), 100
mold, 101
ornamental (illus.), 100
practical uses of (illus.), 100
rusting, 100
Silo (illus.), 102
stable (illus.), 102
sun dial (illus.), 101
tensile strain, 104
tower (illus.), 102
walls (illus.), 100
water tower (illus.), 102
what it is, 95
wood, 102
=Confucius=, philosophy written with brush, 13
=Cooking=, when first used, 308
=Copper=, as a conductor of electricity, 267
wire, telegraph, 266
=Corn plant=, how pollen fertilizes, 170
why it has silk, 176
=Corn Silk=, what it is for, 176
baling presses (illus.), 476
=Cotton=, drawing frames (illus.), 472
slashers (illus.), 475
spinning frames (illus.), 473
warping machine (illus.), 474
what nation produces the most, 477
how much cloth will a pound of cotton make, 477
mill (illus.), 471
cloth, first steps in making, 472
putting fiber on bobbins (illus.), 473
cloth finished (illus.), 476
who discovered, 477
weave room, 475
where it comes from, 470
lapper machines, 471
card room (illus.), 472
bobbins (illus.), 473
dye-house (illus.), 474
beaming frames (illus.), 475
inspecting tables (illus.), 476
field a southern (illus.), 470
breaker machines (illus.), 471
slubber machines (illus.), 472
speeders (illus.), 473
spooling machine (illus.), 474
shipping (illus.), 476
what used for, 477
cloths, what are the principle, 477
=Counting=, man, himself, 19
in tens, 19
in twelves, 20
=Crying=, what makes us, 195
when hurt, why we, 93
=Cross-bow=, invention of, 44
=Crude rubber=, how treated, 378
=Culverins=, early type of, 45
=Cylinder in gas engine= (illus.), 184
=Darkness=, cats can see in, 91
some animals can see in, 91
why we cannot see in, 91
why we fear, 352
=Deep sea diving=, the telephone adjusting (illus.), 202
coming up (illus.), 204
cost of outfit, 203
helmet, putting on (illus.), 202
just before going down (illus.), 204
outfit, 202
shoes, putting on (illus.), 202
suit, putting on (illus.), 202
telephoning from bottom, 203
telephone, testing the (illus.), 203
testing, final (illus.), 203
water pressure at varying depths, 203
wealth recovered by diving, 204
weight of outfit, 203
=Deer-stalking with the cross-bow= (illus.), 42
=Detonators=, in firearms, 47
=Developer=, Pyro, in photography, 23
=Diamonds=, what made of, 351
=Did= candles come before lamps? 294
=Die=, why do we have to, 245
=Difference= in woolens and worsteds, 84
=Dimples=, what causes, 352
=Discovery= of gunpowder, 44
=Discovery= of stringed musical instruments, 479
telephone, 71
=Diver’s= task made easy (illus.), 284
=Diving, deep-sea=, the telephone adjusting, (illus.), 202
cost of outfit, 203
hats of divers, 204
just before going down (illus.), 204
helmet, putting on (illus.), 202
shoes, putting on (illus.), 202
suit, putting on the (illus.), 202
suit, what consists of, 202
telephone from bottom, 203
telephoning, testing the (illus.), 203
testing final (illus.), 203
water pressure at varying depths, 203
wealth recovered by diving, 204
weight of outfit, 203
=Dixie=, what name means, 124
where name originated, 123
=Does= air weigh anything, 398
=Does= the air surrounding the earth move with it? 400
=Does= thunder sour milk, 196
=Does= light weigh anything? 37
=Does= the sun revolve on its axis? 511
=Do= father and mother plants always live together? 176
=Do= the ends of the rainbow rest on land? 254
=Do= the stars really shoot down? 255
=Dog=, why he turns round before lying down, 229
=Dolls=, why girls like, 368
=Dom Pedro=, Emperor of Brazil, who saved the telephone, 73
=Do= plants breathe? 241
=Draft=, created by chimney, 37
=Dreams=, cause of, 366
nightmare, 367
what makes us? 366
=Drinking=, origin of clinking glasses, 232
=Driving shield=, airlock bulkhead (illus.), 210
erector (illus.), 210
in tunnel building (illus.), 208
inventor of, 209
tunnels, front view (illus.), 209
=Ducks=, why water runs off backs of, 233
=Dust=, in air, 38
what it is, 104
=Dyeing=, silk, 121
=Earache=, what causes, 410
=Earth=, how big it is, 124
light surrounding, 38
=Echo=, what makes an, 200
whispering gallery, 201
=Eggs=, birds why different colors, 233
silkworm, how imported, 111
=Egyptians=, how ancients wrote, 12
=Electric arc=, temperature of, 35
=Electric current=, what it is, 334
=Electricity=, conductors of, 331
current, 334
good conductors, 331
how discovered, 333
non-conductors, 331
what is, 329
=Electric lighting=, arc-light, 307
Edison’s first lamp (illus.), 306
incandescent carbon lamp (illus.), 306
Mazda lamp (illus.), 306
tantalum lamp (illus.), 306
Tungsten metal lamps, 305
when introduced, 305
=Elements=, carbon, 352
compared with compounds, 349
hydrogen, 349
nitrogen, 350
oxygen, 349
what an is, 349
=Elevator=, description of (illus.), 397
installation (illus.), 396
principal parts of, 396
why does not the car fall? 397
=Emperor=, saved the telephone, 73
=Emperor of Brazil=, receives first message over first telephone, 74
=Engine, gas= (illus.), 181-182
carburetor, 184
cylinder (illus.), 184
horse-power, of, 256
=Exchange=, first telephone, 75
=Exhibition=, of first telephone at Centennial, 74
=Experiments=, with mirror resultant in photograph, 22
=Exploding=, a submarine mine, 34
=Explosions=, how they break windows, 62
in gas engines (illus.), 182
of submarine mines (illus.), 34
what happens in, 205
=Explosives=, definition of, 205
blasting gelatin, 206
gun-cotton, 206
nitroglycerine, 206
=Eye=, of a submarine (illus.), 274
=Eyes=, closed, walking with, 91
hand quicker than, 376
help brain in walking, 91
in some pictures follow you, why, 36
keeping body balanced, 91
nature’s way of protecting, 38
protecting with tears, 38
sparkle when merry, why, 92
why we can’t sleep when open, 92
why we see stars when hit on, 268
=Eye-wash=, tears as an, 38
=Fabrics=, worsted, 85
=Fahrenheit=, what is meant by, 221
why so called, 221
=Fastest= camera in the world, 25
=Fathers and Mothers=, do plants have, 175
=Federal Government=, grazing fee paid to, 82
=Fertilization=, in birds, 179
how corn plant fertilizes, 176
of fishes, 177
=Fight=, of Merrimac and Monitor, 32
=Film=, before and after snapshot, 23
sensitive, 23
=Finger prints=, arch, (illus.), 520
composite (illus.), 521
of different people, 521
enlargements of, 524
how they identify us, 520
impressions of orang-outang (illus.), 522
loop (illus.), 520
palmary impressions (illus.), 522
specimen form of, record (illus.), 525
spike that caught a criminal (illus.), 524
thieves caught through their, 523
thumb imprint on bottle (illus.), 523
thumb impression on cash box (illus.), 523
thumb mark on a candle (illus.), 523
where first used, 522
whorl (illus.), 521
=Fingers=, why they hurt when cut, 143
why we have ten, 142
=Finger nails=, why we have, 142
=Fire=, alarms when first used, 308
first apparatus to fight, 308
first fire department, 308
first real, fire engine, 308
gases put out, 37
how man discovered, 289
how man learned to fight, 208
how man learned to make a, 289
mark, of civilization, 290
why it goes out, 37
why is it hot? 401
why put out by water, 222
=Fire making=, drilling (illus.), 289
drilling with bow string (illus.), 290
drilling, two persons (illus.), 290
first matches (illus.), 292
flint and pyrites (illus.), 290
flint, introduction of (illus.), 291
plowing (illus.), 290
pyrites (illus.), 290
rubbing sticks together, 42
sawing (illus.), 289
steel and flint (illus.), 291
tinder box (illus.), 291
tinder box, pistol (illus.), 291
with matches, 292
=Firedamp=, 262
explosion in safety lamp, 262
=Firearms=, first crude efforts of, 45
first real (illus.), 45
fuse of, 45
in early Chinese history, 44
first trigger of, 45
=Firing=, mortar, causes gas-rings, 27
=First= man-carrying aeroplane, 128
real telegraph, 421
stringed musical instrument, 480
telephone (illus.), 72
telephone line, 72
telephone switchboard (illus.), 74
=Fishes=, how they are born, 177
how they come to life, 177
motion in swimming, 233
what the eggs are, 177
why they cannot live in air, 232
=Flag=, made, how was American, 310
made, when was American? 310
=Flash pan=, early type, 45
=Flaxseed oil=, what it is, 227
=Flight=, of projectile, long, 30
=Flint-lock=, invented in seventeenth century, 46
invented by thieves, 46
still in use in Orient, 46
=Floor=, sounds through a, 79
=Flour=, bolters (illus.), 465
how made, 462
purifying machine (illus.), 463
sieves, 465
=Flowers=, why they have smells, 176
=Flying=, how birds learn, 178
boat, wonderful (illus.), 133
first Langley monoplane, 126
first successful aeroplane (illus.), 126
machine, first models, 127
some of the men who helped, 126
ten years of (illus.), 137
=Flying boat=, fun in (illus.), 135
gliding by, 137
=Flying boat=, interior arrangement (illus.), 134
monoplane type (illus.), 135
six-passenger hull (illus.), 134
speed of (illus.), 135
the wonderful, 133
views of (illus.), 133
=Flying machines=, 126
Bleriot flew in Europe (illus.), 129
Curtis biplane in flight (illus.), 136
Dr. Langley’s flying (illus.), 127
early types of, 127
first demonstrations, 130
first flight in Europe with, 129
first man-carrying aeroplane, 128
first models, 127
flying boat, 133
flying boat, exterior arrangement, 134
gliding experiments, 137
government interest in, 138
hull of flying boat, 134
interesting governments in, 138
Wright Bros., first flights, 130
=Focus=, in eye, 22
=Fog=, what it is, 105
=Food=, how we learned to cook, 308
=Foreign monoplanes=, some famous (illus.), 132
=Forsythe, LL.D. J.=, inventor of the primer, 47
=Freckles=, what makes them come, 125
=Fuse=, for firearms in early history, 45
=Funditor=, 42
=Gas=, acetylene, 305
definition, 348
first structure to be lighted by, 302
in coal mines, 262
water, 305
=Gas, illuminating=, Baltimore first city to use, 302
carbon in, 302
discovered, when, 302
first American house to use, 302
first practical demonstration of, 302
generator house (illus.), 299
holder (illus.), 298
how it gets into jet, 302
how it is purified, 303
how made, 303
how the meter works, 304
hydrogen in, 302
impurities removed from (illus.), 301
jet, the story in a, 303
made of, 302
meter, description, 304
purifying boxes (illus.), 301
removing tar from, 300
shaving scrubbers (illus.), 300
=Gasoline engine= (illus.), 181, 182
=Gases=, generated at gun muzzle, 27
how expelled in gun ingot, 55
hydrogen, 349
nitrogen, 350
oxygen, 349
tendency to put out fire, 37
=Gas-rings=, in firing motor, 27
=Gatling=, inventor of guns, 310
=Gelatine=, in photography, 23
=Gestures=, talking by, 18
=Ghosts=, what are they? 367
=Glad=, why do we laugh when, 92
=Glass=, why it cracks, 63
how long known, 247
=Glass, plate=, casting (illus.), 249
commercial, 246
plate and window glass compared (illus.), 252
=Glass, plate, making=, annealing, oven, 249
beveling, 247
blanketing, 252
clay mixing (illus.), 248
clay trampling (illus.), 248
clay used, 247
grinding table, 250
materials used in, 247
mercury, 253
nitrate of silver, 253
pots (illus.), 248
pots, drying of, 248
pots, length of usefulness, 248
silvering, 247
skimming the pot (illus.), 249
treading, 247
=Glow-worm=, why does it glow? 231
=Gold=, why is it called precious? 266
=Gong=, why does it stop when it has been sounded, 78
=Good luck=, why a horseshoe brings? 311
=Graphite= in lead pencils, 468
=Gravitation=, what is, 267
=Gravity=, center of, in gun, 61
=Gravity=, force of, 61
=Greek fire=, in early history, 44
=Growing=, why do we stop, 195
=Gun=, action at muzzle, 27
annealing a gun ingot, 57
assembling of, 48-54
arquebus of, 1537, 47
barrels, erosion of, 35
blow-holes, 56
bore searcher, 59
breech of a, 53
discharges, force of, 33
calibre of a, 53
elastic limit, 58
elongation, 58
forging a (illus.), 52
heat treatment, 58
hoops of a, 54
improvements in, 45
ingot, calibre of, 55
jacket of, 54
length of a, 53
liner of, 54
life of, 35
manufacture in America, 48
measuring inside diameter (illus.), 59
modern built-up (illus.), 54
mold for ingot, 55
muzzle of, 53
pressure generated in a big gun, 54
photography (illus.), 33
piping, 56
powder chamber of a, 53
rifling (illus.), 60
rifling of, 53
shrinking pit, 59
tensile strength of, 58
factory, testing materials, (illus.), 50
tube of, 54
tube, how it is tempered, 57
why called gatling, 310
wire-wound, 54
=Gun-barrels=, imported from England, 49
resisting pressure of, 34
=Gun-cotton=, in smokeless powder, 35, 206
=Gunpowder=, Chinese probable discovers of, 44
discoverer of, 44
experiments by Schwartz, 45
formula of Roger Bacon, 45
ingredients in, 205
manufactured in monasteries, 44
what causes the smoke? 206
smokeless, what made of, 206
why some is fine and others large grained, 206
=Gurgle=, in bottles, 63
=Hail=, what causes, 124
=Hair=, what causes baldness, 143
why it don’t hurt when cut, 143
why it keeps growing, 144
=Hand bombards=, early types, 45
=Hands=, shaking, why with the right, 231
=Hansom=, why so called, 122
=Have= plants fathers and mothers? 175
=Heart=, why beats during sleep, 191
why beats faster when scared, 191
why beats faster when running, 191
=Heat=, light wave changed into, 36
why a nail gets hot when hammered, 230
why some things are warm, 144
how we obtain, 231
=Hemp=, Manilla (illus.), 356
=Hobson’s choice=, how originated, 311
=Honey=, apiary in summer (illus.), 534
how produced, 527
worker comb (illus.), 532
manner of using German bee-brush, 533
finished product (illus.), 533
frame (illus.), 535
how to bump the bees off a comb (illus.), 533
bee-hat (illus.), 535
a study in cell-making (illus.), 532
bee sting, can a, 536
frame of bees (illus.), 535
comb, how bees build, 536
=Honey-bee=, poison-bag, 537
egg of queen, under microscope (illus.), 529
preparing for rearing, 531
living on combs in open air, (illus.), 527
the daily growth of larvæ (illus.), 532
effect of a sting (illus.), 536
worker-bee (illus.), 527
what the queen-bee does? 528
drone-comb (illus.), 532
clipping queen bees wings (illus.), 533
cucumber blossom with bee on it (illus.), 528
queen-bee (illus.), 527
the queen and her retinue (illus.), 529
queen-rearing, 531
queen-cells (illus.), 529
=Honeymoon=, why do they call it a? 311
=Horizon=, how far away is the, 245
what is it, 244
where is it, 244
=Horse-power=, a, what it is, 256
=Horseshoes=, why it is said to bring good luck? 311
=Hot box=, cause of, 368
=Houiller=, French gunsmith, 48
=Houses=, concrete (illus.), 101
=How= far does the air extend? 243
is ammunition made (illus.)? 49
does an arc light burn? 307
are automobile tires made? 382
does a honey bee live? 336
does a bee make honey? 527
do bees build the honey comb? 536
does the honey bee defend itself? 536
does honey develop in a comb (illus.)? 530
do birds learn to fly? 178
do birds find their way? 407
does the blotter take up the ink of a blot? 18
this book is bound, 578
this book is made, 561
the paper in this book is made, 561
the pictures in this book are made, 581
are bullets made? 51
is an ocean cable laid? 429
does a camera take a picture? 22
is a cable dropped into the ocean (illus.)? 432
are modern carpets made? 169
is a carpet woven by machinery? 171
is china decorated? 406
is china made? 404
is chocolate made? 392
did the custom of clinking glasses in drinking originate? 232
are cigars made? 517
is cloth made from wool? 86
did the coal get into the coal mines? 257
does a coal mine look inside? 260
do the cocoa beans grow (illus.)? 391
is the color put on the outside of the pencil? 469
is the honey comb made? 532
are concrete roads built (illus.)? 103
did man learn to cook his food? 308
are concrete buildings made (illus.)? 100
is woolen cloth dyed? 87
big is the earth? 124
much of the earth does the sun shine on at one time? 324
does an elevator go up and down (illus.)? 396
was electricity discovered? 333
does the light get into the electric bulb? 305
is the eraser put on a pencil? 469
can an explosion break windows? 62
explosions may occur on submarines, 278
does the farmer use concrete (illus.)? 102
do our finger prints identify us? 520
did man learn to fight fire? 308
did man learn to make a fire? 289
are fishes born? 177
was the flag made? 310
is flour made? 462
does a fly walk upside down? 454
did men learn to fly? 126
does the gas get into the gas jet? 302
is illuminating gas made? 303
is gas purified? 303
is plate glass made? 246
is plate glass ground? 250
a wire-wound gun is made? 54
was the first American gun made (illus.)? 47
is a gun ingot made? 55
do we find the length of a gun? 53
is a gun tube tempered? 57
do we obtain heat? 231
the heel of a shoe is put on (illus.), 560
did Hobson’s choice originate? 311
far away is the horizon? 245
does a key turn a lock (illus.)? 491
does a spring lock work (illus.)? 492
are lead pencils made? 467
do the miners loosen the coal? 261
is light produced, 230
are magnets made? 335
are matches made? 293
are match boxes made? 294
did man learn to send messages? 412
does the meter measure the gas? 304
can microbes spread through the body? 410
are mirrors silvered? 522
big is a molecule? 348
did money originate? 455
are moving pictures made? 369
does the music get into the piano? 478-482
did the word news originate? 312
did a nod come to mean yes? 19
did shaking the head come to mean no? 19
are paints mixed? 228
is a photograph developed? 23
was the piano discovered? 479
do plants breathe? 241
do plants reproduce life? 175
does the shield cut through the ground in tunnel building? 212
are shooting shells photographed? 24
shoes are made by machinery, 549
shoe machinery was developed, 457
is crude rubber secured? 377
is rope turned and twisted? 358
are rubber tires made? 378
are modern rugs made? 169
to splice a rope, 364
do men go down to the bottom of the sea? 202
did the sand get on the seashore? 108
far back does the silkworm date? 109
was silk introduced into Europe? 110
are the silkworms cared for? 113
do we know a thing is solid, liquid or gas? 348
are sounds produced? 485
fast does sound travel? 486
can sound come through a thick wall? 79
is the volume of sound measured? 242
far does space reach? 256
do the slate pickers work? 259
does a captain steer his ship across the ocean? 407
can a ship sail under water, 269
is a submarine submerged? 270
do sponges grow? 286
do sponges eat? 287
are sponges caught? 287
are the stars counted? 241
big is the sun? 141
hot is the sun? 141
is a steel pen made (illus.), 17
did man learn to shoot, 40
do we get wool off the sheep? 82
is a stone thrown with a sling? 41
are metallic and paper shells filled with powder? 50
did man learn to talk? 18
did the telephone come to be? 70
fast does thought travel? 242
does a telegram get there? 414
did man learn to tell time? 313
did man begin to measure time? 314
did men tell time when the sun cast no shadows? 317
is the time calculated at sea? 315
is tobacco cultivated? 516
is tobacco cured? 516
was tobacco discovered? 512
is tobacco harvested? 515
is tobacco planted? 514
is a tunnel dug under water? 208
does water put fire out? 222
is white lead made? 225
are wires put under ground? 76
did writing first come about? 11
did the Chinese write? 13
did the Monks do their writing? 14
does a pen write? 18
much does the wool in a suit of clothes cost? 83
much wool does America produce? 82
is wool taken from the sheep? 82
is the yarn for carpets dyed? 170
is oxide of zinc obtained? 226
does the water get into the faucet? 501
are the big water pipes laid? 504
did the name Uncle Sam originate? 458
=Human body=, wonders of the, 311
=Hunting=, with the bow-and-arrow, 43
=Hurt=, why we cry when, 93
=Hydrogen=, what it is, 349
=Hypo=, used in developing, 23
=Impact=, of projectile from guns, 28
=Ink=, how does a blotter take up? 18
=Instruments=, artillery, testing, 24
musical, 488
optical, based on refraction, 38
=Incandescent lamp=, development of, 306
=Inside= of a mine planting submarine (illus.), 277
=Iron=, cast, 265
melts at, 35
the most valuable metal, 265
wrought, 265
=Is= a moth attracted by a light? 288
man an animal? 180
the hand quicker than the eye? 376
there a reason for everything? 200
there a man in the moon? 400
yawning infectious? 192
=Jacket=, of a gun, 54
=Japan= the natural home of the silk worm (illus.), 112
=Kentucky rifles=, 45
=Key=, how it works in a lock (illus.), 491
=Knots=, different kinds of (illus.), 363
what makes, in boards, 223
=Lambs=, Siberian, in South Dakota (illus.), 80
=Lamps=, first street light in America, 296
the Clanny safety, 264
did candles come before? 294
earliest forms of, 295
Edison’s first (illus.), 306
incandescent carbon (illus.), 306
incandescent, development of, 306
incandescent, electric, when invented, 305
French watch tower (illus.), 295
Mazda (illus.), 306
from Nushagak hanging (illus.), 297
Pagan votive (illus.), 296
Tantalum (illus.), 306
street, when first used, 295
chimney protects flame, 37
coal miners and safety, 262
=Lamp chimney=, why it makes a better light, 37
=Langley, Dr. Samuel P.=, 1914 flight of aeroplane, 128
=Languages=, why so many, 197
=Lantern=, the first oil (illus.), 297
the “Réverbère” (illus.), 297
=Laugh=, when glad, why we, 92
nerves, 93
when tickled, why we, 93
=Laughter=, reflex action, 93
=Lead=, as used in making paint, 267
in a pencil, 468
why so heavy, 267
as used in pipes for plumbing, 267
=Leather=, how the hides are treated, 539
treatment of hides, 538
unhairing machine (illus.), 540
hide house (illus.), 538
tanning process, 539
rolling room (illus.), 539
tanning sole leather, 539
how upper leather is tanned (illus.), 540
disposing of waste material, 540
wringers, 539
tan yard (illus.), 539
=Legs=, not same length, 91
=Lens=, in the eye, 22
=Leyden jar=, what it is, 332
=Life=, beginning of, 174
beginning of man’s, 174
how plants reproduce, 175
=Light=, attracting moths, 288
glow-worms why they glow? 231
how produced, 230
lightning bugs, made by, 231
where it goes when it goes out, 36
what makes match, 198
in mirror, 22
in negative, 23
rays, 36, 495
broken rays of, 38
rays, heat from, 36
and refraction, 38
speed of, 36, 140
travels faster than anything in the world, 36
surrounding earth, 38
wave changed into heat, 36
=Lighting=, arc, how does it burn, 307
in America, first street (illus.), 296
first oil lantern, 297
electric, when introduced, 305
first street light in Paris, 297
gas tank, (illus.), 298
=Lightning=, why it follows thunder, 140
=Lightning bugs=, why they produce light, 231
=Lignite=, found in coal mines, 262
=Liner=, of a gun, 54
=Linseed oil=, extraction of, 228
what it is, 227
where it comes from, 227
=Liquid=, definition, 348
=Living=, why do some people live longer, 199
reproduction necessary why, 174
reproduction of, in birds, 179
reproduction of, in fishes, 177
=Loading= machines in powder factory, 50
=Lobsters=, red, what makes them, 245
=Lock=, cylinder (illus.), 492
how a key turns a (illus.), 491
how key changes are provided (illus.), 491
how a spring lock works (illus.), 492
master-keyed cylinder (illus.), 492
what happens when the key is turned? (illus.), 491
what happens when the knob is turned? (illus.), 491
=Locomotives=, boiler of articulate type (illus.), 440
boiler of (illus.), 442
cab of (illus.), 442
cylinders description of, 441
low pressure cylinders of (illus.), 441
electric, newest (illus.), 443
one of the largest (illus.), 440
signal tower, latest (illus.), 444
stoker, automatic (illus.), 443
water tank (illus.), 444
=Lodestone=, what it is, 327
“=Long Bow=,” in Sherwood Forest (illus.), 42
=Loom=, cloth making machine, 86
=Magnet=, breaking iron (illus.), 330
electro (illus.), 326, 328, 335
electric lift (illus.), 326
experiments with, 327
great lifting by (illus.), 330
how made, 335
what makes it lift things? 326
wonders performed by, 326
work it can do (illus.), 328
=Man=, writing, how man learned, 11
counting himself, 19
is he an animal? 180
=Matches=, are they poisonous? 294
first, 292
how made, 293
lucifer (illus.), 292
making by machinery, 293
modern safety (illus.), 292
oxymuriate (illus.), 292
promethean (illus.), 292
what we would do without, 292
when first used (illus.), 292
=Match-lock=, of early firearms, 45
=Melting= of iron, 35
=Men= who made the telephone, 70
=Mercury=, fulminate of, 49
=Merrimac and Monitor=, fight of, 32
=Merry=, why eyes sparkle when, 92
=Messages=, how men learned to send, 412
Indian smoke signals, 412
marathon runner by (illus.), 413
pony telegraph (illus.), 413
=Messenger boy=, how to call a (illus.), 414
the first (illus.), 413
=Metal=, what is a, 265
what is the most valuable? 265
why we use for coining, 456
=Meter=, description of gas, 304
how it measures gas, 304
=Milk=, does thunder sour? 196
=Milky way=, why is it called, 255
what is, 255
=Mine cars= (illus.), 260
=Mines=, clearing channel of buoyant, 283
exploding submarine, 34
planting submarine, inside of (illus.), 277
workers that never see daylight, 258
=Mirror=, collects rays of light, 22
reflection in, 22
reflects rays of light, 22
=Mirrors=, beveling (illus.), 251
how made, 251
how silvered, 252
polishing, 251
roughing, 251
silvered with mercury, 253
silvering mirror plates (illus.), 252
=Molecule=, how big is a, 348
what is a, 348
=Monasteries=, where gunpowder was manufactured, 44
=Money=, how originated, 455
metallic forms of, 456
who made the first cent, 458
who originated, 455
why do we need, 455
why gold and silver are best for coining, 457
=Monitor and Merrimac=, fight of, 32
=Monks=, making gunpowder, 44
=Monoplane=, flying boat (illus.), 135
German (illus.), 132
over Mediterranean (illus.), 132
=Moon=, why it travels with us, 399
the man in the, 400
=Morse, S. B.=, inventor of telegraph, 420
=Mortars= (illus.), 26
=Mothers and Fathers=, do plants have, 175
=Moths=, attracted by light, 288
emerging from cocoon (illus.), 117
=Motion= bodies, swiftest, 25
=Motion=, is train harder to stop than start? 223
of light, 140
of sound, 140
perpetual, 61
perpetual, in mechanics, 240
=Motors=, gas, used in aeroplanes, 130
=Mountains=, what made them, 401
=Moving pictures=, Board of Censors, 373
developing room (illus.), 372
drying room (illus.), 373
continuous movement of film, 376
exact size of film, 370
first camera, 375
first exhibited at studio, 372
how made, 369
how freak pictures are made, 376
negative, stock, 370
negative, perforated, 370
“Pigs is Pigs” (illus.), 374
rehearsing (illus.), 371
scenario (illus.), 374
staging, 371
taking a (illus.), 373
=Mulberry trees=, food for silk worms (illus.), 112
=Mules and drivers= (illus.), 258
=Multiple switchboard= of telephone, 69
=Music=, harp, 479
lyre, 479
note, what it is, 490
what pitch is, 489
what is, 478
=Musical talking machines=, 490
=Muzzle=, of a big gun, 53
=Muzzle-loaders=, in Civil War, 47
=Nails=, why they get hot when hammered, 230
=Names=, of people, 20
=Nature=, protecting eyes, ways of, 38
=Navigating= on bottom of sea, 283
=Negative= in photography, 23
=Nerves=, sensory, receive impression, 93
transmitting impression, 22
=News=, how did the word originate? 312
=Nightmare=, cause of, 367
=Nitrogen=, what it is, 350
=Ocean=, why is it blue? 219
what makes it green? 219
why don’t water sink in? 219
where did all the water in, come from? 218
where is water at low tide, 219
=Of= what use is my hair? 143
=Of= what use are pains and aches? 410
=Oil baths=, for gun (illus.), 57
=Oil cake=, from linseed, 228
=Oil=, palm olive, in soap, 411
=Omniscope=, of submarine boat, 271
=Onions=, make tears, 38
bad effect of on eyes, 38
=Operatives=, in powder factory, girls as, 49
=Optical instruments=, based on refraction, 38
=Organic matter=, what it is, 174
=Origin of cement=, 95
of counting in tens, 19
names of people, 20
of nodding to indicate yes, 19
of shaking head to indicate no, 19
of turnpike, 104
=Oxide of zinc smelter= (illus.), 227
how obtained, 226
=Oxygen=, what it is, 349
in air, 37
=Pain=, of what use is, 410
what it is, 244
=Paint=, care of, story in, 224
how mixed, 228
uses of, 224
what used for, 224
=Paint manufacturing=, colors, what makes different, 229
buckles before corrosion (illus.), 225
buckles after corrosion (illus.), 225
buckles placed in stacks (illus.), 225
buckles taken from stacks (illus.), 225
first step in making (illus.), 224
lead buckles making (illus.), 224
lead, white, how made, 224-225
lead white used in, 224
grinding lead in oil (illus.), 228
washing the lead (illus.), 226
mixing, 228
where paints are mixed (illus.), 228
linseed oil, where obtained, 227
pressing oil from flaxseed (illus.), 228
removing oil cake from press, 228
sulphur roasting furnace (illus.), 226
zinc smelter (illus.), 227
oxide of zinc, how made, 226
=Paper=, earliest forms of, 14
sensitive in photography, 23
shells, inspection of (illus), 49
papyrus, the first, 14
=Papyrus=, invention of, 14
=Patents=, of original telephone, 73
=Peat=, as a fuel, 262
=Pen=, first metallic (illus.), 15
first steel (illus.), 15
first metallic pen, how made, 15
how it writes, 18
invention of the, 15
=Pencils, “lead”= where from, 466
eraser is put on, 469
making description of (illus.), 467
who made the first? 466
=Periscope=, description of, 275
how we look through a (illus.), 276
mirror of, 275
=Perpetual motion=, nearest approach to, 240
is it possible? 61
=Persian rug=, antique (illus.), 167
how made, 167
imitation (illus.), 167
Kurdistan (illus.), 167
where best are made, 167
=Photographs=, of projectiles, 25
=Photography=, resultant from experiments with mirror, 22
=Piano=, pitch, 489
finishing (illus.), 484
why not more than seven octaves, 480
Dulcimer (illus.), 479
spinet (illus.), 480-481
note what it is, 490
sounding board, 488
tuning, (illus.), 484
building case around (illus.), 483
how the music gets into the, 482
clavichord (illus.), 480
instruments, musical, 488
strings, fastening on (illus.), 482
psaltery, 480
sound box, the first, 479
who made the first, 478
hammers (illus.), 483
action regulation (illus.), 484
virginal (illus.), 480-481
first (illus.), 478
tuning fork, 488
polishing (illus.), 484
sounding board, putting on the (illus.), 482
how discovered, 479
lyre, 479
octave, 480
harpsichord (illus.), 480-481
=Pickers=, boy, slate (illus.), 259
=Pictures=, with a fast camera, 39
moving, how made, 369
size of moving film, 370
never seen by the human eye, 31
taken in one five-thousandth of a second, 31
=Pin money=, why they call it? 231
how name originated, 231
=Pistols=, invented in Pistola, Italy, 46
=Plants=, corn, why it has silk? 176
do father and mother plants live together, 176
how they eat, 511
how they reproduce, 175
why do flowers have smells? 176
why they produce leaves, 175
=Plate glass=, (illus.), 246
=Portland Cement=, why called, 95
=Powder=, filling shells, 50
gun-cotton in smokeless, 35
secret of smokeless powder, 35
smokeless, 35
in submarine mines, amount of, 34
=Pressure=, generated in bore of a big gun, 54
inside of a gun at discharge, 33
in gun-barrel, resistance of, 34
of light, on scales, 37
=Primer=, invented by, 47
=Prof. Bell’s= vibrating reed (illus.), 71
=Projectiles=, photographs of, 25
arrival at target, 24
clear of smoke-zone (illus.), 30
smoke-zone, emerging from (illus.), 29
height in air from mortar, 30
impact of, from guns, 28
leaving gun muzzle (illus.), 27
travel faster than sound, 32
velocity of, 33
viewed in transit, 33
weight of, 53
=Proving grounds=, for big guns, (illus.), 53
=Pyro=, used in developing, 23
=Quarry=, cement (illus.), 96
=Quill the=, in writing (illus.), 14
=Quills=, raising geese for, 14
=Rails, steel making=, blast furnace (illus.), 234
blooming mill (illus.), 237
crane, carrying ingot, (illus.), 236
length of, 238
mixer (illus.), 234
molten steel, pouring (illus.), 236
open hearth furnace (illus.), 235
pouring side of open hearth furnace, 235
shrinkage of, 238
soaking pit (illus.), 236
temperature in furnace, 235
=Rain=, where it goes, 222
why it freshens the air, 222
=Rainbow=, cause of, 253
colors in, what makes? 254
ends of, 254
=Rays=, change their course, 38
heat from light, 36
of light, 36
Roentgen, 307
=Rays-X=, what are they? 307
=Reason=, is there one for everything? 200
=Reed=, the (illus.), 12
=Reflection=, in mirror, 22, 91
=Refraction=, changing light rays called, 38
of light, 38
=Reproduction=, of life, in birds, 179
in fishes, 177
in plants, 175
why we must have, 174
=Rifle=, Kentucky, 45
kick of, 47
modern automatic, 47
over-loading, 47
wheel-lock (illus.), 46
=Rifling=, causes rotation of projectile, 32
a big gun (illus.), 60
of a gun, 53
invented in Austria, 46
=Roads=, concrete (illus.), 103
=Roentgen Rays=, 307
=Rope=, breaker (illus.), 360
compound laying machine (illus.), 361
cross-section, 362
draw frame (illus.), 360
drying fiber, 354
Egyptian kitchen (illus.), 354
Egyptians making (illus.), 353
preparing the fiber in (illus.), 359
four-strand (illus.), 362
hackling, 354
hemp (illus.), 356
hemp in warehouse (illus.), 356
knots, 363
lengths, standard, 362
oiling in manufacture, 356
long made by hand, 354
machine (illus.), 358
opening bales of fiber (illus.), 359
preparation room (illus.), 359
scraping fiber (illus.), 354
sliver formation of (illus.), 360
spindles, 355
spinning after turn, 355
=Rope spinning=, after turn, 355
foreturn, 355
splicing (illus.), 364
spreader (illus.), 360
stakes, 355
=Rope walk=, modern (illus.), 357-358
old-fashioned (illus.), 355
=Routine=, of a telephone call (illus.), 68
=Rubber=, automobile tires, 382
biscuit, 377
blisters, 379
blow holes, 379
breaker-strip, 384
calendering, 381
castilloa, 387
cement, 381
crude, 377-378
curing room, 382-383
dryer, 379
fabric, 384
furnishing pneumatic tires (illus.), 386
gathering (illus.), 377
how secured, 377
how are inner tubes made, 385
marketing balls of, 377
mixing, 379
Para, 387
pneumatic tires, 383
pure, why not used, 380
spreading, 381
spreader room (illus.), 383
tapping (illus.), 377
tire building machines (illus.), 385
tires, how made, 378-379-380
tread laying room, 384
tubes, inner, how made, 385
vulcanizing, 384
washing, 378
wild, what is, 387
why not used pure, 380
wrapping room, 386
=Rugs=, designs imitated by machinery, 168
Persian (illus.), 167
Persian, how made, 167
Persian, imitation, 167
Persian Kurdistan (illus.), 167
Persian, where best are made, 167
Tabriz, reproduction (illus.), 168
weaving by machine (illus.), 171
=Rug manufacturing=, carding machine (illus.), 170
examining and repairing (illus.), 173
packing for shipment (illus.), 173
processes, 169-170
weaving by machinery (illus.), 171
wool sorting, 170
=Sadness=, cause of tears, 38
=Salt=, beds, 493
chemical name of, 493
in water, 351
mines, 493
Salt Lake, 493
soda, 493
supply for United States, 493
wells, 493
where it comes from, 493
=Scales=, pressure of light on, 37
=School slates=, where they come from, 495
=Score=, origin of, 26
=Scouring=, wool (illus.), 85
=Scouring and weaving=, in making woolen cloth (illus.), 88
=Screens=, in shot tower, 51
=Sea=, diver, 202
how men go down to the bottom of, 202
navigating on bottom of, 283
time calculated on the, 315
what the bottom looks like, 202
what makes it roar, 401
=Second=, reckoning in millionths of a, 25
pictures taken in one five-thousandth of a, 31
=Seeds=, why plants produce, 175
=Seeing=, why we cannot see in dark, 91
=Sensation=, of sight, 22
=Sensitive=, paper, 23
=Service=, military, U. S., 24
=Shadows=, cause of, 495
=Shell=, sounds in a, 79
=Shells=, filling with powder, 50
inspection of metallic (illus.), 49
putting metal heads on paper, 50
wad-paper in making, 50
=Sheep=, coming out of forest (illus.), 82
first in America, 80
fleece packing, 82
how much wool does a sheep produce? 83
how wool is taken from the, 82
how taken care of, 82
how we get wool off of, 82
industry in America, 80
industry in the colonies, 81
industry in the west, 81
number in the west, 81
shearing, 82
shearing machines, 82
wool-producing, 83
why sheep precede the plow in civilizing a
country, 81
=Shield driving=, air lock bulkhead (illus.), 210
caulking the joints (illus.), 214
description of airlocks, 213
erector at work (illus.), 214
erector (illus.), 210
at end of journey (illus.), 216
grommetting the bolts (illus.), 214
grouting (illus.), 214
how it cuts in tunnel building, 212
how they meet exactly (illus.), 215
in tunnel building (illus.), 208
key plate (illus.), 214
curves around (illus.), 216
models of Penna. R.R. tunnel shields (illus.), 212
rear end in tunnel building (illus.), 210
tunnels, front view (illus.), 209
=Ship=, how does a captain steer his, 407
how can it sail under water? 269
=Shoes=, Amazeen skiving machine, 550
assembling machine (illus.), 552
automatic heel loading and attaching
machine (illus.), 560
automatic leveling machine (illus.), 559
automatic sewing machine, 555
American made, 547
ancient and modern forms of sandals, (illus.), 543
ancient sandal maker (illus.), 541
beginning of a shoe (illus.), 549
boot developed from the sandal, 544
boots (illus.), 546
channel cementing machine (illus.), 558
channel laying machine (illus.), 559
channel opening machine (illus.), 558
Crakrow or peaked (illus.), 544
which church and law forbade (illus.), 544
description of ancient sandal (illus.), 542
dyeing out machine, 551
different parts come together, 551
duplex eyeletting machine, 550
edge trimming machine (illus.), 560
Ensign lacing machine, 551
evolution cf the sandal to the shoe (illus.), 542
first machine for making shoes, 545
hand method lasting machine (illus.), 553
heel breasting machine (illus.), 560
heel trimming machine (illus.), 560
ideal clicking machine, 550
Inseam trimming machine (illus.), 556
insole tacking, 551
lasting machine (illus.), 553
loose nailing machine (illus.), 559
success of McKay machine, 547
machine that forms and drives tacks, 554
machines which punch the soles of, 559
my lady’s slippers (illus.), 548
placing shank and filling bottom, 556
planet rounding machine, 551
power tip press, 550
pulling over machine (illus.), 552
putting the ground cork and rubber cement in, 556
rolling machine, 551
rounding and channelling machine (illus.), 557
sewing the sole on, 558
slugging machine (illus.), 560
sole laying machine (illus.), 557
Summit splitting machine, 551
upper stapling machine (illus.), 554
upper trimming machine (illus.), 554
welt and turned shoe machine (illus.), 555
welt beating and washing machine, 556
welt sewing machine, 551
what was the first foot covering like? 541
“whipping the cat,” 545
who made the first shoe in America? 545
work performed by heeling machine (illus.), 560
=Shooting tests= (illus.), 48
=Shotguns=, assembling of, (illus.), 48
=Shot pellets=, 51
=Shrinking=, pit for big gun, 59
=Shuttle=, In weaving wool, 86
=Siberian lambs=, in South Dakota (illus.), 80
=Signs=, talking by, 18
=Silica=, mine (illus.), 247
=Silk=, 109
called “bomby-kia,” 110
caring for young worms, 113
culture, 110
drying skeins of, 119
dyeing, 121
first step in manufacture, 119
first used, 109
hatching eggs, 113
introduction of into Europe (illus.), 110
number of cocoons in pound of, 117
manufacture of, 119
method of reeling, 113
moths depositing eggs (illus.), 112
preparing cocooning beds, 112
reeling silk from cocoon (illus.), 118
spinning (illus.), 120
thread made uniform (illus.), 120
threads ready for the weaver, 121
twisting (illus.), 120
use of, 109
water-stretcher (illus.), 121
winding (illus.), 119
=Silk manufacture=, doubling frames, 120
spinning, 120
twisting, 120
=Silk moth=, description of 114
=Silkworm=, age, 115
first breeder of, 109
chrysalis (illus.), 114
cocoon, 115
cocoon, beginning of (illus.), 116
cocooning bed (illus.), 112
description of, 114
domestication of, 111
eating (illus.), 115
female moth (illus.), 114
how cared for, 113
how it eats, 115
home of, 112
eggs, how imported, 111
hatching the eggs (illus.), 113
how he does his work, 114
larvæ of, (illus.), 114
motions of head in spinning, 115
molting season, 115
moths emerging from cocoon (illus.), 117
male moth (illus.), 114
mulberry branches for (illus.), 112
one of the world’s greatest wonders, 116
preparing for making cocoon (illus.), 116
reared, how they (illus.), 115
shedding old skin, 115
spinneret of the, 115
spinning cocoon, 115
wild, 109
=Silver=, definition of, 207
use, history of, 207
why does it tarnish, 266
=Silver bromide=, in photography, 23
=Skins=, used for clothing, 80
=Sky=, will it ever fall? 255
why is it blue? 253
=Soap=, lye in, 411
palm olive oil in, 411
what made of, 411
=Soda=, Leblanc process, 494
Solvay process, 494
where we get, 494
=Solids=, definition, 348
=Some= wonders of the human body, 311
=Sound=, deadening of, 79
first over a wire, 71
how measured, 242
how produced, 485
speed of, 140-486
travels through air slowly, 31
in a sea shell, 79
what is, 78-485
waves, 79
waves, length of, 487
where comes from, 78
=Slate pencil=, why cannot write on paper with, 18
=Sleep=, where are we when, 365
with eyes open, why we cannot, 92
ghosts, 367
why heart beats during, 191
why we go to, 365
restless, 92
=Sling=, man in action (illus.), 41
how first made, 41
=Slings=, and their drawbacks, 42
=Slow match=, of early firearms, 45
=Smells=, why do flowers have, 176
=Smoke-cone=, in gun-firing (illus.), 28
=Smokeless powder=, 35
=Smoke-rings=, hard as steel, 27
=Smoke signals=, of Indians, 412
=Smoke-zone=, in gun firing, 111
=Sneezing=, what makes us, 194
why do we, 194
=Snowflakes=, what makes them white? 409
=Space=, extends, how far, 256
=Sparkle=, when merry, why eyes, 92
=Spear=, as a weapon, 42
=Specific gravity=, meaning of, 268
=Speed=, of light, 36
=Spinneret=, of the silkworm, 115
=Spinning wheel=, in making cloth from wool, 81
=Sponge=, capillary attraction of, 18
=Sponges=, breeding time of, 286
how do they grow? 286
how they eat, 287
how they are caught, 287
where they come from? 286
=Stable=, underground (illus.), 158
=Stars=, counted in photograph, 223
do they shoot down? 255
how counted, 241
how many there are, 223
photographed, 223
what makes them twinkle, 38
=Steamship=, beginning of (illus.), 337
cross-section, 346
building of a (illus.), 337
cradle of a, 338
double bottom, 339
end to end section, 346-347
funnel (illus.), 345
gantry (illus.), 338
hull (illus.), 341
hull before launching (illus.), 340
inside of (illus.), 346-347
launching of a (illus.), 340
launching machinery (illus.), 341
ready to launch (illus.), 340
plates (illus.), 339
ribs (illus.), 338
skeleton (illus.), 339
turbine, weight of, 344
turbine (illus.), 344
=Steel pen=, how made, 16
=Steel rail making=, blast furnace (illus.), 234
Blooming mill and engine (illus.), 237
dump buggy, 237
crane, carrying ingot (illus.), 236
ingot, 237
ingot becomes a rail (illus.), 238
mixer (illus.), 234
molten steel being poured into ladle (illus.), 236
open-hearth furnace (illus.), 235
furnace, pouring sides of an open hearth (illus.), 235
iron, purification of, 235
soaking pit (illus.), 236
furnace, temperature in, 235
=Stick=, why it bends in water, 38
making a fire with, 42
=Stockings=, where it goes when the hole comes, 64
=Stone-throwing=, 41
=Stones=, where they come from, 494
=Story= in an automobile, 181
in a loaf of bread, 460
in a book, 561
in a building foundation, 496
in a cablegram, 428
in a barrel of cement, 95
in a stick of chocolate, 388
in a suit of clothes, 80
in a lump of coal, 257
in a bale of cotton, 470
of a cup and saucer, 404
of the deep sea diver, 203
in an electric light, 305
in an elevator, 395
in a finger print, 520
in a flying machine, 126
in a gas jet, 303
in a gun, 40
in a honey bee, 526
in a magnet (illus.), 326
in a lead pencil, 466
in lighting a fire, 289
in a lock, 491
in a can of paint, 224
in a pen, 11
in a piano, 478
in a photograph, 22
in “Pigs is Pigs” (illus.), 374
in a pipe and cigar, 512
in a railroad engine, 440
in a coil of rope, 353
in a ball of rubber (illus.), 378
in a rug, 167
in a pair of shoes, 541
in a steel rail (illus.), 234
in a submarine boat (illus.), 269
in a lump of sugar, 145
in a telegram, 412
in the telephone, 65
in a time piece, 313
in a tunnel, 208
in a drink of water, 501
in a window pane, 246
in the wireless, 455
in a yard of silk, 109
in a piece of leather, 538
=Stringed instruments=, the first, 480
discovery of, 479
=Stretching=, why do we, 192
what happens when we, 193
=Stylus=, iron, 13
the in writing (illus.), 11
=Submarine=, accidents and their causes, 278
air and how it may become poisonous, 278
buoyancy of, 270
“Bushnell’s Turtle,” 280
cargo, recovering of, 285
clearing a channel of buoyant mines (illus.), 283
development of, 280-281
divers’ compartment, 270
equilibrium, 270
explosions, 278
first practical (illus.), 271
gas, explosion of, 278
“G-1” (illus.), 272
Holland, 282
how we look through a periscope (illus.), 276
hydroplanes on, 270
hydroplane, 282
ice, under (illus.), 279
inside of a (illus.), 272
lens, of periscope (illus.), 276
living quarters (illus.), 285
mice on, 278
mine planting inside of (illus.), 277
Omniscope, 271
one of the first practical, 271
“Proctor,” first practical, 271
“Proctor” submerged (illus.), 271
periscope top of (illus.), 276
rudder, horizontal, 270
sailing close to surface (illus.), 273
seeing in all directions at once, 276
Simon Lake, American inventor of, 282
steadiness of (illus.), 273
under the ice (illus.), 279
submergence, 270
water pressure on, 270
who made the first, 280
=Submarine boat=, “Argonaut the First” (illus.), 269-282
“Argonaut Junior” (illus.), 269-282
who made the first, 280
=Submarine mines=, amount of powder used, 34
=Sugar=, carbonatation station (illus.), 150
chemical laboratory in factory (illus.), 149
circular diffusion battery in factory (illus.) 149
filter presses (illus.), 150
how taken from beets, 150
sulphur station (illus.), 150
washing the beets, 149
=Sugar factory=, carbonatation station (illus.), 150
chemical laboratory in (illus.), 149
circular diffusion battery (illus.), 149
filter presses (illus.), 150
sulphur station (illus.), 150
=Suit=, cost of wool in a, 83
=Sulphite of soda=, used in developing, 23
=Sun=, distance from earth, 141
revolving on its axis, 511
=Sun-dial= (illus.), 315
in determining noon (illus.), 316
concrete (illus.), 101
=Sunlight=, effect on balance, 37
=Sunset=, cause of colors in, 253
=Swallowing=, what happens when we, 195
=Swimming=, why man must learn, 125
=Switchboard=, telephone, 69
back of a, telephone (illus.), 69
telephone, the first (illus.), 74
=Talking=, how man learned talking, 18
signs and gestures, 18
=Talking machines=, 490
=Target=, floating, 31
Never seen by men firing mortar, 29
projectile, arrival at, 24
=Tears=, caused by onions, 38
as an eye-wash, 38
run along channel, 38
where they come from, 94
where they go, 94
=Teeth=, why they are called wisdom, 125
why they chatter, 218
=Telegram=, how it gets there, 414
story in a, 412
=Telegraph=, cables (illus.), 424
code, 419
calling a messenger, 414
waiting calls (illus.), 414
arrival at destination (illus.), 417
duplex, 417
electric, 420
electric, first suggestion of, 420
inventor of, 420
two men inventors of, 421
instruments, 425
instruments, first sending (illus.), 426
instrument, sending, 418
key, modern (illus.), 427
key, a later, 427
key, sending (illus.), 418
line, first, 422
messenger receives message (illus.), 415
messages, number sent in a day, 417
multiplex, 417
operating room (illus.), 423
the pony (illus.), 413
quadruple, 417
Wheatstone, receiver (illus.), 425
Wheatstone sender (illus.), 425
receiving operator (illus.), 416
relay, the first (illus.), 426
relay, modern (illus.), 427
recording apparatus first (illus.), 426
recording instrument improved, (illus.), 427
repeater room (illus.), 424
sending operator (illus.), 416
sounder, modern (illus.), 427
main switchboard (illus.), 423
automatic typewriter (illus.), 425
=Telephone=, apparatus, 65
birthplace of (illus.), 70
cost of number in use (illus.), 77
display board (illus.), 65
discovery of, 71
feeding cable into duct (illus.), 76
first outdoor demonstration, 75
how an emperor saved the, 73
forces behind your, 77
modern distributing frame (illus.), 75
line, the first, 72
line lamp, 66
pilot lamp, 66
from bottom of ocean, 203
operator, 67
breaking up the asphalt pavement (illus.), 76
a cable trouble (illus.), 76
call routine of (illus.), 68
beginning of service, 75
the first switchboard, 72
laying multiple duct subway (illus.), 76
first practical commercial test of telephone, 75
how wires are put underground (illus.), 76
nine million in use, 75
the first words over, 74
=Tens=, counting in, 19
=Test=, of big gun (illus.), 53
=Testing=, materials and products in gun factory (illus.), 50
artillery instruments, 24
=Tests=, shooting (illus.), 48
=Things=, to know about a big gun, 53
=Throats=, making sounds with our, 78
=Thread=, silk, made uniform (illus.), 120
=Thunder=, why it precedes lighting, 140
does it sour milk? 196
=Tickled=, why we laugh when, 93
=Tides=, where does water go at, low, 219
=Time=, age of clocks, 391
blacksmith’s clock (illus.), 320
first modern clock, 319
hour-glass (illus.), 317
time-boy of India (illus.), 317
where the day changes, 325
where is the hour changed? 325
clock in Independence Hall (illus.), 323
clock in New York City Hall (illus.), 323
largest clock in the world, 321
machinery which runs a big clock (illus.), 322
how man measured, 314
modern clock, description of (illus.), 319
primitive twelve-hour clock, 318
water clocks for, 317
water-clock (illus.), 318
man’s first divisions of, 314
what it is, 313
three great steps in measuring, 316
first methods of telling (illus.), 313
in New Testament, 314
sun-dial (illus.), 315
sun-dial in determining noon, 316
calculated at sea, 315
tower of the winds (illus.), 318
how told when sun casts no shadows, 317
=Tin=, why used for cooking utensils, 267
=Tobacco=, barn, 515
growing crop, care of, 514
growing under cheesecloth (illus.), 512
grown in Cuba, 513
cultivation of, 516
curing of, 515
cigars, how made, 517
how discovered, 512
field (illus.), 515
figures about, 519
filler, 518
fertilization, 514
where it comes from, 512
shade growing, 517
where does it grow, 512
harvesting, 515
Havana, where grown, 513
origin of name, 512
planting, 514
seed beds, 514
first care in selection, 518
strippers, 518
bulk sweating, 516
wrappers, 518
butter worm, 514
=Toes=, why we have ten, 142
=Toothache=, what good can come from? 410
cause of, 410
=Torches=, used in battles, 44
=Tow-line=, of floating target, 31
=Trains=, why harder to stop than start, 223
=Transparent=, why some things are, 350
=Trees=, found in coal, 261
=Tube=, of a gun, 54
=Tunnels=, accidents in, 218
causes of accidents, 218
accuracy of engineering, 215
airlocks, description of, 213
operation of airlocks, 213
compressed air method, 211
the bends, 213
bends, the danger of, 213
bends, the symptoms of, 213
dangers in building, 218
grommetting the bolts, (illus.), 214
borings in ground (illus.), 216
airlock bulkhead (illus.), 210
how built, 209
driving shield rear end of in tunnel building (illus.), 210
caissons in Hudson tunnels (illus.), 217
curves, how made (illus.), 216
how shield cuts through, 212
how dug under water, 208
erector (illus.), 210
erector at work (illus.), 214
grouting (illus.), 214
inventor of shield method, 209
inventor of compressed air method, 211
caulking the joints (illus.), 214
making joints water tight, 214
at end of journey (illus.), 216
land end of Hudson tunnels (illus.), 217
danger of leaks, 213
result of leaks (illus.), 213
concrete lining (illus.), 216
key plate (illus.), 214
diagrams of driving shield (illus.), 208
biggest ever built by shield method, 209
rear end of driving shield (illus.), 210
driving shield front view (illus.), 209
how the shields meet exactly (illus.), 215
models of Penna RR. tunnel shield (illus.), 212
=Turbine=, how it works (illus.), 344
=Twinkle=, what makes stars, 38
=Twinkling stars=, due to interference, 38
=Types= of cartridges (illus.), 49
=Umbrella=, who made the first, 312
who carried the first, 312
=Uncle Sam=, how name originated, 458
=Undercutting= with compressed air machine (illus.), 261
=Vault= of telephone cables (illus.), 67
=Velocity= of a projectile, 53
=Waking=, why we wake up, 365
=Walking=, difficult to, straight with eyes closed, 91
why cannot babies walk as soon as born, 180
=Wall=, sounds through a thick, 79
=Water=, aqueduct (illus.), 505
Ashokan Reservoir (illus.), 502
boiling-point of, 35-220
drinking, where does it come from, 501
hard, 221
how is a big dam built, 502
Hudson River siphon (illus.), 507
in ocean where it came from, 218
pumping station (illus.), 503
real source of the (illus.), 506
regulating chamber (illus.), 506
reservoir, 503
soft, 221
as standard in measuring specific gravity
solids, 268
what made of, 348
what makes it boil, 220
what makes water shoot in air, 198
what hard is, 221
what soft is, 221
why don’t water in ocean sink in, 219
why does it run, 219
why it puts fire out, 222
why runs off a duck’s back, 233
why sea water is salty, 351
=Watson, Thomas A.=, (illus.), 70
=Wave=, of light changed into heat, 36
=Waves=, of sound, 79
=Weight=, of light, 37
of projectiles, 53
=What= does the air weigh? 398
animal can leap the greatest distance? 122
causes an arrow to fly? 408
makes some people bald? 143
keeps a balloon up? 199
makes a ball stop bouncing, 63
are ball bearings? 180
happens when a bee stings? 537
makes the hills look blue sometimes? 255
makes me blush? 194
was the origin and meaning of bread? 460
is the hottest spot on earth? 239
holds a building up? 496
makes a bubble explode, 108
is carbonic acid? 509
is a cable made of? 429
is the eye of the camera? 22
do ocean cables look like when cut in two? (illus.), 428
do we mean by 18-carat fine? 266
is clay? 495
is color? 123
produces the colors we see? 123
makes the colors in the rainbow? 254
makes the colors of the sunset? 253
are cocoa shells? 390
is cement? 95
is cement used for? 95
a cement mill looks like (illus.), 96
is cement made of? 95
is cement used for, 95
is concrete? 95
makes some things in the same room colder than others? 144
does woolen cloth come from? 80
was the cross-bow? 44
are diamonds made of? 351
causes dimples? 352
makes us dream? 366
were man’s first divisions of time? 314
makes things whirl around when I am dizzy? 402
is dust? 104
becomes of the dust? 104
are drone bees good for? 531
is meant by deadening a floor or a wall? 79
causes earache? 410
makes an echo? 200
are the principal parts of an elevator? 396
causes the explosion in a gas engine? (illus.), 182
happens when anything explodes? 205
is an element? 349
makes the hollow place in a boiled egg? 179
is electricity? 329
is an electric current? 334
makes an electric magnet lift things? 326
do we mean by Fahrenheit? 221
makes a fish move in swimming? 233
is fog? 105
makes the water from a fountain shoot into the air? 198
makes freckles come? 125
makes a gasoline engine go? 181
is gravitation? 267
does specific gravity mean? 268
makes a cold glass crack if we put hot water in it? 63
are ghosts? 367
causes the gurgle when I pour water from a bottle? 63
causes hail? 124
is the horizon? 244
causes a hot box? 368
good are the lines on the palms of our hands? 402
does horse-power mean? 256
is hydrogen gas? 349
makes us feel hungry? 243
makes knots in boards? 223
were the earliest lamps? 295
were the lamps of the wise and foolish maidens? 295
happens when we laugh? 93
makes us laugh when glad? 92
is a leyden jar? 332
is a lodestone? 327
makes lobsters turn red? 245
makes the lump come in my throat when I cry? 195
makes a match light when we strike it? 198
would we do without matches? 292
is a metal? 265
is the most valuable metal? 265
is the milky way? 255
is a molecule? 348
is money? 455
is motion? 61
made the mountains? 401
is music? 478
does a note in music consist of? 490
is organic matter? 174
is oxygen? 349
is nitrogen? 350
makes nitroglycerin explode so readily? 206
causes nightmare? 367
is pain and why does it hurt? 244
makes the different colors in paint? 229
is pitch in music? 489
is the principle of the wireless? 455
makes some pencils hard and others soft? 467
makes rays of light? 230
makes us red in the face? 192
makes the rings in the water when I throw
a stone into it? 197
is rubber? 386
is wild rubber? 387
should I do if stung by a bee? 537
is the cause of shadows? 495
makes the sea roar? 401
does the bottom of the sea look like? 220
becomes of the smoke? 106
and why is smoke? 105
causes the smoke when a gun goes off? 206
is smokeless powder made of? 206
makes snowflakes white? 409
depth of snow is equivalent to an inch of rain? 241
is soap made of? 411
makes a soap bubble? 108
shot tower looks like? 51
makes us sneeze? 194
is silver? 207
happens when we stretch? 193
makes me want to stretch? 192
happens when I swallow? 195
is sound? 485
are the properties of sound? 486
are the sounds we hear in a sea shell? 79
makes the sounds like waves in a sea shell? 79
does a sounding board do? 488
is meant by the length of sound waves? 487
makes us thirsty? 243
makes me tired? 403
a great steamship looks like inside (illus.), 346
did the first telephone look like? (illus.), 72
occurs when we think? 194
are the big tanks near the gas works for? 298
makes the stars twinkle? 38
a ship’s turbine looks like (illus.), 344
is the largest tree in the world? 242
happens when we telephone? 65
makes water boil? 220
is the boiling-point of water? 220
causes a whispering gallery? 201
makes a wireless message go? 455
makes the works of a watch go? 368
makes the white caps on the waves white? 410
is worry? 207
causes the wind’s whistle? 139
makes the kettle whistle? 198
causes wrinkles? 196
are X-rays? 307
is yeast? 288
=When= did man first try to fly? 126
did man begin to live? 174
were candles introduced? 296
was illuminating gas discovered? 302
was wheat first used in making bread? 461
I throw a ball into the air, while walking why does it follow me?
401
was silk culture introduced in America? 111
were street lamps first used? 295
=Where= does bread come from? 460
does water in the ocean go at low tide? 219
does silk come from? 109
are we when asleep? 365
did the name calico come from? 123
cement is obtained (illus.), 97
does chalk come from? 18
does chocolate come from? 388
our coal comes from? 257
does cotton come from? 470
does the day begin? 324
does the day change? 325
did the term Dixie originate? 123
does honey come from? 526
is the horizon? 244
does the hour change? 325
the gas is taken from the coal (illus.), 299
did all the names of people come from? 20
did the expression “kick the bucket” originate? 321
does leather come from? 538
do living things come from? 174
did life begin on earth? 174
do we get ivory? 239
do lead pencils come from? 466
does the wooden part of a lead pencil come from? 469
does a light go when it goes out? 36
does linseed oil come from? 227
does paint come from? 224
does the rain go? 222
are the best Persian rugs made? 167
does rope come from? 353
does salt come from? 493
do we get soda? 494
do all the little round stones come from? 494
does the part of a stocking go that was where the hole comes? 64
does sound come from? 78
do school slates come from? 495
do shoes come from? 541
do sponges come from? 286
do tears come from? 94
do the tears go? 94
did the name tobacco originate? 512
is Havana tobacco grown? 513
does tobacco come from? 512
does tobacco grow? 512
did all the water in the ocean come from? 218
does our drinking water come from? 501
does most of our wool come from? 81
does the wind begin? 139
is the wind when it is not blowing? 139
does wool come from? 80
did the term Yankee originate? 243
=Wheat=, bread loaves of the world, 459
grinding (illus.), 464
harvesting (illus.), 460
scouring of, 463
tempering of, 463
when first used in making bread, 461
will it grow wild? 461
=Wheel-lock= rifle (illus.), 46
=Whispering gallery=, accidental, 201
cause of, 201
what it is, 201
=Whistle=, what makes the kettle? 198
=White Lead=, making (illus.), 225
buckles, before corrosion (illus.), 225
buckles after corrosion (illus.), 225
buckles, making, 225
=Who= started to make clothing from wool in America? 81
discovered electricity? 333
invented electric telegraph? 420
made the first felt hat? 239
made the first cent? 458
made the first submarine boat? 280
first discovered the silkworm? 109
first discovered the power of gunpowder? 44
invented flying? 126
made the first piano? 478
brought the first sheep to America? 80
first wove silk thread into cloth? 109
make the first shoes? 541
made the first umbrella? 312
=Why= don’t the air ever get used up? 140
can’t we see air? 140
do we grow aged? 196
does an apple turn brown when cut? 106
do coats have buttons on the sleeves? 64
has a long coat buttons on the back? 64
cannot babies walk as soon as born? 180
are some people bald? 144
don’t the birds stay South? 408
does a ball bounce? 63
does a balloon go up? 199
do we call voting balloting? 122
does a barber pole have stripes? 310
do some things bend and others break? 62
do the birds come back in the Spring? 407
do birds sing? 408
do birds go South in the Winter? 407
are birds’ eggs of different colors? 233
has a bee a sting? 336
can you blow out a candle? 21, 36
are bubbles round? 108
does red make a bull angry? 490
do we get a bump instead of a dent when we knock our heads? 201
can’t we burn stones? 105
has a long coat buttons? 64
is bread so important? 460
do I get out of breath when running? 191
do we call a cab a hansom? 122
does a hen cackle after laying an egg? 233
do children like candy? 409
is cement called Portland cement? 95
do I get cold in a warm room? 125
is it cold in winter? 141
does cold make our hands blue? 192
does an ear of corn have silk? 170
do we count in tens? 10
we cannot see in the dark, 91
does the dark cause fear? 352
do we have to die? 245
does a dog turn round and round before he lies down, 229
do we know we have dreamed when we wake up? 367
does eating candy make some people fat? 409
doesn’t an elevator fall? 397
do our eyes sparkle when we are merry? 92
do the eyes of some pictures follow us? 35
is it difficult to walk straight with my eyes closed? 91
do I get red in the face? 192
are some faculties stronger than others? 403
is a fire hot? 401
does a fire go out? 37
we fear the dark? 352
cannot fishes live in air? 232
do we have finger nails? 142
are our fingers of different lengths? 142
have we five fingers on each hand and five toes on each foot? 142
do we have finger nails? 142
does a gasoline engine go? 181
do girls like dolls? 368
is gold called precious? 266
are gold and silver best for coining? 457
is some gun-powder fine and others coarse grained? 206
are some guns called gatling guns? 310
does a glow-worm glow? 231
do we stop growing? 195
do we have hair? 143
does the hair grow after the body stops growing? 144
don’t my hair hurt when it is being cut? 143
does my hair stand on end when I am frightened? 143
is the right hand stronger than the left? 309
does my heart beat faster when I am scared? 191
does the heart beat when the brain is asleep? 191
do our hearts beat faster when we are running? 191
do they call it a honeymoon? 31
is a horseshoe said to bring good luck? 311
does it hurt when I cut my finger? 143
we cry when hurt, 93
does iron turn red when red hot? 107
does iron sink in water? 106
doesn’t an iron ship sink? 106
do we have twelve men on a jury? 239
does a lamp give a better light with the chimney on? 37
are there many languages? 197
do we laugh when glad? 92
is lead so heavy? 267
do they call them lead pencils? 466
must life be reproduced? 174
are some people light and others dark? 402
did people of long ago live longer than we do now? 199
do we use metal for coining? 456
do they call it the milky way? 255
do we need money? 455
does the moon travel with us when we walk or ride? 399
should we not sleep with the moon shining on us? 366
do my muscles get sore when I play ball in the spring? 310
does a nail get hot when hammered? 230
do we have only seven octaves on a piano? 480
does the ocean look blue at times? 219
does oiling the axle make the wheel turn more easily? 400
does an onion make the tears come? 38
can’t I write on paper with a slate pencil? 18
does a pencil write? 18
are some races white and others black, yellow and brown? 537
do they call it pin money? 231
do we call them pistols? 46
do plants produce seeds? 175
does a poker get hot at both ends if left in the fire? 107
does rain make the air fresh? 222
are most people right-handed? 403
don’t we make roads perfectly level? 104
don’t we use pure rubber? 380
does salt make us thirsty? 351
don’t the scenery appear to move when I am in a street car? 399
does the scenery appear to move when we are riding in a train? 399
can cats and some other animals see in the dark? 91
can we see farther when we are up high? 245
do I turn white when scared? 193
does silver tarnish? 266
does the sheep precede the plow in civilizing a country? 81
is the sky blue? 253
do I sneeze? 194
do we see stars when hit on eye? 268
many stars are there? 223
does a stick in water bend? 38
does a sound stop when we touch a gong that has been sounded? 78
can we make sounds with our throats? 78
do people shake with the right hand? 231
do we go to sleep? 365
does it seem when we have slept all night that we have been asleep
only a minute? 366
can’t we sleep with our eye open? 92
we can hear through speaking tubes, 487
does a human being have to learn to swim? 125
are cooking utensils made of tin? 267
do we use copper telegraph wires? 266
do my teeth chatter? 218
are some things transparent and others are not? 350
do I laugh when tickled? 93
can we think of only one thing at a time? 193
does thunder always come after the lightning? 140
do we call them wisdom teeth? 125
are some roads called turnpikes? 104
is the sea water salt? 351
will water run off a duck’s back? 233
do we worry? 207
don’t the water in the ocean sink in? 219
is it warm in summer? 141
does water run? 219
do we say water is soft or hard? 221
does a piece of wood float in water? 106
do we wake up in the morning? 365
do I yawn? 173
does yeast make bread rise? 288
=Will= people all be bald sometime? 144
the sky ever fall down? 255
=Windows=, how an explosion breaks them, 62
=Wireless=, accidents, prevention of, 449
aerial on R. R. stations (illus.), 451
aerial on ship (illus.), 455
antennæ, 447
antennæ on trains (illus.), 450
battery, 447
coil, 447
compass, 454
development of, 454
direction finder, 454
distance of sending, 448
equipment, 446
first Marconi station, 452
how it reaches ships at sea, 446
icebergs (illus.), 449
in the army (illus.), 447-448
inventor of, 452
key, 447
masts, height of, 448
G. Marconi, portrait, 452
on trains (illus.), 450
prevents accidents, 449
principles of, 455
receiving station in U. S. Army (illus.), 451
spark gap, 447
stations, shore (illus.), 446
stations on trains (illus.), 450
transmission automatic (illus.), 453
transmission of messages (illus.), 453
what kind of signs are used in? 446
why don’t the message go to the wrong stations, 455
world-wide use, 454
=Wires=, copper telegraph, 266
how put underground (illus.), 76
wire-wound gun, 54
=Wonders= performed by electric lift magnet (illus.), 326
=Wool= beaming (illus.), 89
bobbin in weaving machine, 86
Burling (illus.), 88
burr picker, 87
carding, 85
carding, finisher in cloth making (illus.), 89
chloride of aluminum in making cloth, 87
cleaning, 85
made clothing from, 81
combing (illus.), 86
cost of in a suit of clothes, 83
crop of the United States, 82
dyeing, 85-87
fabrics, 85
fiber description, 83
finishing, box (illus.), 87
finish, perching (illus.), 90
fulling cloth (illus.), 90
gilling after carding (illus.), 86
gilling and making top after combing (illus.), 86
gilling (illus.), 87
greasy matter in, 84
how we get it off the sheep, 82
how much does a sheep produce, 83
how much does America produce, 82
how made into cloth, 85
how woolen cloth is made perfect, 88
how shipped, 82
loom, 86
mending, perching (illus.), 88
mending room (illus.), 88
woolen mule spinning (illus.), 89
napping, 89
next to food as a vital necessity, 81
piece dyeing (illus.), 90
quality of a hundred years ago, 83
raised to sell to manufacturers, 81
reducer machine in wool making (illus.), 87
ring twisting (illus.), 89
shipped to manufacturers, 82
shuttle in weaving, 86
scouring (illus.), 85
sorting (illus.), 84
spinning process, 86
spinning, 89
English cap spinning, 89
in one suit of clothes, 83
sulphuric acid solution in making cloth, 87
teasel, 89
tramper, 82
in United States, bulk of, 82
warp thread, 86
web, 86
weaving (illus.), 88
where does most of our wool come from? 81
woof of, 86
made into yarn, 86
yarn inspecting (illus.), 89
yolk of, 84
=Woolen cloth=, ready for market (illus.), 90
=Woolens and worsteds=, difference between, 84
=Woolworth building= (illus.), 395
=Words=, formation of, 19
the first over a telephone, 74
=World’s= bread loaves (illus.), 459
=Worry=, definition of, 207
what it is, 207
Why we, 207
=Worsted= carding (illus.), 85
fabrics, 85
=Worsteds and woolens=, difference of, 84
=Wright Brothers=, first successful flights, 130
=Wrinkles=, what causes, 196
=Writing=, brush, the (illus.), 13
earliest ways of, 12
first done upon rocks, 11
first imitation of, 12
first metallic pen introduced, 15
fluids for developing, 13
how man learned to, 11
how the monks did their, 14
how a pen writes, 18
modern way of, 16
paper for, earliest, 14
pen, invention of, 11
pen, first steel (illus.), 15
quill, the (illus.), 14
Reed, the, in (illus.), 12
steel tube pen in (illus.), 15
steel pen, modern (illus.), 16
Stylus, the (illus.), 11
with chalk, 18
why a pencil writes, 18
=X-rays=, what are they? 307
=Yankee=, where word originated, 243
=Yarn=, made from wool, 86
=Yawning=, why do, 173
is it infectious, 192
=Yeast=, what it is, 288
why it makes bread rise, 288
=Yes=, meaning of nod, 19
=Zollner, Casper=, inventor of rifling, 46