Название | The Reason Why |
---|---|
Автор произведения | Robert Kemp Philp |
Жанр | Математика |
Серия | |
Издательство | Математика |
Год выпуска | 0 |
isbn | 4064066154523 |
See-saw, why may a little boy balance a larger boy, 863
See-saw, why does the little boy sink to the earth, when the larger boy kicks the ground, 861
LESSON LXIII.
See-saw, why may the little boy keep the larger one up, when once he is up, 864
Shadows, what is the cause of, 508
Shadows, why is there some light where shadows fall, 510
Shadows, why do they lengthen as the sun goes down, 526
Shuttle-cock, why does it travel slowly through the air, 836
Shuttle-cock, why do we hear a noise when we strike it with the battledore, 837
Sight, why are two persons able to see each other, 551
Sight, why can we see so many upon the small retina, 966
Sight, why are we able to see at long or short distances, 974
Sigh, why do we, 1025
Silica, what is it, 1260
Silk, what is it, 1200
Skin, why does a chill of the produce inflammatory action in the lungs, 1014
Sky, what is it, 530
Sky, why is it red at sunset, 532
Sleet, what is it, 447
Sleep, what is it, 1019
Smell, why do we, 992
Smoke, what is it, 102
Smoke, why is there so little when the fire is red, 105
Smoke, what is it, 289
LESSON LXIV.
Smoke, why do fresh coals increase the quantity of, 291
Smoke, why does it issue in folds and curls, 632
Smoke, why does it ascend in mild and fine weather, 689
Snails, why can they move in an inverted position, 666
Snails, where do they obtain their shells, 1306
Snails, why do their shells grow, 1307
Snails, why are their shells spiral, 1308
Snails, why have they four tentacula attached to their heads, 1309
Snails, why are they able to move without feet, 1310
Snails, why do we see none in the winter time, 1311
Snails, why can they live in sealed shells, 1312
Sneeze, why do we, 1024
Snipes and woodcocks, why have they long, tapering bills, 1042
Snore, why do we, 1028
Snow, why does it keep the earth warm, 160
Snow, why is it a good non-conductor of heat, 162
Snow, what is it, 440
Snow, why is it white, 441
LESSON LXV.
Snow, why is it warm, though white garments are cool, 442
Snow, why is it always on the tops of high mountains, 443
Snow-line, what is meant by the, 445
Snow, what is red, 446
Soda-water, why does it effervesce, 802
Soils, why are clayey unfavourable to vegetation, 1160
Soils, why are sandy unfavourable to vegetation, 1162
Soils, why are chalk unfavourable to vegetation, 1162
Soils, why are mixed favourable to vegetation, 1163
Soils, why do farmers manure their land, 1165
Soot, why should it be prevented from accumulating at the bottom and sides of saucepans, 205
Soot, what is it, 290
Sound, what is it, 716
Sounds, what causes the air to produce, 717
Sounds, how do we know that they are produced by vibrations, 718
Sounds, how do we know that without air there would be none, 719
Sounds, how are the vibrations of sonorous bodies imparted to the air, 720
LESSON LXVI.
Sounds, how rapidly do the vibrations of travel, 721
Sounds, do all sounds travel at the same rate, 722
Sounds, why are bells and glasses stopped from ringing by touching them with the finger, 723
Sounds, why does a cracked bell give discordant, 724
Sounds, why do we see the flash of a gun before we hear the report, 725
Sound, why does the marching of long ranks of soldiers appear to be irregular, 726
Sounds, what are the numbers of vibrations that produce various, 727
Sounds, why does the length of a wire or string influence the sounds it produces, 728
Sound, why does the tension of a wire or string affect its vibrations, 729
Sound, why are some notes low and solemn, and others high and quick, 730
Sound, why can our voices be heard at a greater distance when we speak through tubes, 731
Sound, is air a good conductor, 732
Sounds, why can we hear them at a greater distance on water than on land, 733
LESSON LXVII.
Sound, why do sea-shells give a murmuring noise when held to the ear, 734
Sound, why can people in the arctic regions converse when more than a mile apart, 735
Sounds, why do savages lay their heads upon the earth to catch sounds, 736
Sounds, why can church clocks be heard striking more plainly at some times than at others, 737
Sound, why may the scratching of a pin at one end of a long pole be heard at the opposite extremity, 738
Sound, why is the hearing of deaf persons assisted by ear-trumpets, 739
Sounding-boards, why are they used to improve the hearing of congregations, 740
Sounds, why, when we are walking under arches or tunnels, do our voices appear louder, 747
Spark, what causes it when a horse's shoe strikes against a stone, 340
Specific gravity, what is it, 789
Spiders, why have they the power of spinning webs, 1082
Spiders,