Q.Why arewoollensandfursused incoldweather forclothing?A. Because they arevery bad conductorsof heat; and, therefore,prevent the warmth of the body from being drawn offby the cold air.
Q.Why arewoollensandfursused incoldweather forclothing?
Q.Why arewoollensandfursused incoldweather forclothing?
A. Because they arevery bad conductorsof heat; and, therefore,prevent the warmth of the body from being drawn offby the cold air.
A. Because they arevery bad conductorsof heat; and, therefore,prevent the warmth of the body from being drawn offby the cold air.
Q.Do not woollens and furs actuallyimpartheat to the body?A. No; they merelyprevent the heat of the body from escaping.
Q.Do not woollens and furs actuallyimpartheat to the body?
Q.Do not woollens and furs actuallyimpartheat to the body?
A. No; they merelyprevent the heat of the body from escaping.
A. No; they merelyprevent the heat of the body from escaping.
Q.Where would the heatescapeto, if the body werenotwrapped in wool or fur?A. The heat of the body wouldflyoff into the air; for the cold air (coming into contact with our body)would gradually draw away its heat, till it was as cold as the air itself.
Q.Where would the heatescapeto, if the body werenotwrapped in wool or fur?
Q.Where would the heatescapeto, if the body werenotwrapped in wool or fur?
A. The heat of the body wouldflyoff into the air; for the cold air (coming into contact with our body)would gradually draw away its heat, till it was as cold as the air itself.
A. The heat of the body wouldflyoff into the air; for the cold air (coming into contact with our body)would gradually draw away its heat, till it was as cold as the air itself.
Q.What then is theprincipal useofclothingin winter-time?A.To keep the body air-tight; and prevent theexternal air(or wind) fromcoming into contact with it, to absorb its heat.
Q.What then is theprincipal useofclothingin winter-time?
Q.What then is theprincipal useofclothingin winter-time?
A.To keep the body air-tight; and prevent theexternal air(or wind) fromcoming into contact with it, to absorb its heat.
A.To keep the body air-tight; and prevent theexternal air(or wind) fromcoming into contact with it, to absorb its heat.
Q.Why arebeasts coveredwithfur,hair, orwool?A. Because fur, hair, and wool are veryslow conductors of heat; and (as dumb animals cannot be clad like human beings) God has given them arobe of hairor wool, tokeep them warm.
Q.Why arebeasts coveredwithfur,hair, orwool?
Q.Why arebeasts coveredwithfur,hair, orwool?
A. Because fur, hair, and wool are veryslow conductors of heat; and (as dumb animals cannot be clad like human beings) God has given them arobe of hairor wool, tokeep them warm.
A. Because fur, hair, and wool are veryslow conductors of heat; and (as dumb animals cannot be clad like human beings) God has given them arobe of hairor wool, tokeep them warm.
Q.Why arebirdscovered withdownorfeathers?A. Because down and feathers arevery bad conductors of heat; and (as birds cannot be clad like human beings) God has given them arobe of feathers to keep them warm.
Q.Why arebirdscovered withdownorfeathers?
Q.Why arebirdscovered withdownorfeathers?
A. Because down and feathers arevery bad conductors of heat; and (as birds cannot be clad like human beings) God has given them arobe of feathers to keep them warm.
A. Because down and feathers arevery bad conductors of heat; and (as birds cannot be clad like human beings) God has given them arobe of feathers to keep them warm.
Q.Why arewool,fur,hair, orfeatherssuchslow conductorsof heat?A. Because agreat quantity of airlurks entangled between their fibres; andair is a very bad conductor of heat.
Q.Why arewool,fur,hair, orfeatherssuchslow conductorsof heat?
Q.Why arewool,fur,hair, orfeatherssuchslow conductorsof heat?
A. Because agreat quantity of airlurks entangled between their fibres; andair is a very bad conductor of heat.
A. Because agreat quantity of airlurks entangled between their fibres; andair is a very bad conductor of heat.
Q.Ifairbe abad conductorof heat, why should we not feel as warmwithoutclothing, as when we are wrapped in wool and fur?A. Because the air (which is cooler than our body)is never at rest; and, therefore, fresh particles (perpetually passing over our body)keep drawing off the heat little by little.
Q.Ifairbe abad conductorof heat, why should we not feel as warmwithoutclothing, as when we are wrapped in wool and fur?
Q.Ifairbe abad conductorof heat, why should we not feel as warmwithoutclothing, as when we are wrapped in wool and fur?
A. Because the air (which is cooler than our body)is never at rest; and, therefore, fresh particles (perpetually passing over our body)keep drawing off the heat little by little.
A. Because the air (which is cooler than our body)is never at rest; and, therefore, fresh particles (perpetually passing over our body)keep drawing off the heat little by little.
Q.Why does the ceaselesschangeof air tend todecreasethewarmthof a naked body?A. Thus:—the air which cases the bodyabsorbs as much heat from it as it can, while it remains in contact; it is then blown away, and makes room for afresh coat of air, which does thesame.
Q.Why does the ceaselesschangeof air tend todecreasethewarmthof a naked body?
Q.Why does the ceaselesschangeof air tend todecreasethewarmthof a naked body?
A. Thus:—the air which cases the bodyabsorbs as much heat from it as it can, while it remains in contact; it is then blown away, and makes room for afresh coat of air, which does thesame.
A. Thus:—the air which cases the bodyabsorbs as much heat from it as it can, while it remains in contact; it is then blown away, and makes room for afresh coat of air, which does thesame.
Q.Does theair(which encases a naked body) become by contact aswarmas thebodyitself?A. It would do so, if it remainedmotionless; but as it remains onlya very short time, it absorbs as much heat as itcan in the time, and passes on.
Q.Does theair(which encases a naked body) become by contact aswarmas thebodyitself?
Q.Does theair(which encases a naked body) become by contact aswarmas thebodyitself?
A. It would do so, if it remainedmotionless; but as it remains onlya very short time, it absorbs as much heat as itcan in the time, and passes on.
A. It would do so, if it remainedmotionless; but as it remains onlya very short time, it absorbs as much heat as itcan in the time, and passes on.
Q.Why do we feelcolderinwindy weather, than in acalmday?A. Because (in windy weather) the particles of airpass over us more rapidly; and everyfreshparticle takes from ussomeportion of heat.
Q.Why do we feelcolderinwindy weather, than in acalmday?
Q.Why do we feelcolderinwindy weather, than in acalmday?
A. Because (in windy weather) the particles of airpass over us more rapidly; and everyfreshparticle takes from ussomeportion of heat.
A. Because (in windy weather) the particles of airpass over us more rapidly; and everyfreshparticle takes from ussomeportion of heat.
Q.Show the wisdom of God in making theairabad conductor.A. If air were agood conductor(like iron and stone) the heat would be drawnso rapidly from our body, that we must bechilled to death. Similar evils would be felt also by all the animal and vegetable world.
Q.Show the wisdom of God in making theairabad conductor.
Q.Show the wisdom of God in making theairabad conductor.
A. If air were agood conductor(like iron and stone) the heat would be drawnso rapidly from our body, that we must bechilled to death. Similar evils would be felt also by all the animal and vegetable world.
A. If air were agood conductor(like iron and stone) the heat would be drawnso rapidly from our body, that we must bechilled to death. Similar evils would be felt also by all the animal and vegetable world.
Q.Does not the bad conducting power of air enable persons to judge whether aneggbeneworstale?A. Yes; touch your tongue against the shell at the larger end; if itfeels warmto the tongue, theegg is stale; ifnot, it is new-laid.
Q.Does not the bad conducting power of air enable persons to judge whether aneggbeneworstale?
Q.Does not the bad conducting power of air enable persons to judge whether aneggbeneworstale?
A. Yes; touch your tongue against the shell at the larger end; if itfeels warmto the tongue, theegg is stale; ifnot, it is new-laid.
A. Yes; touch your tongue against the shell at the larger end; if itfeels warmto the tongue, theegg is stale; ifnot, it is new-laid.
Q.Why will theshellof astale eggfeelwarmto the tongue?A. Between the shell and the “white of the egg”there is a small quantity of air, whichexpands in a stale egg, from theshrinking of the white.
Q.Why will theshellof astale eggfeelwarmto the tongue?
Q.Why will theshellof astale eggfeelwarmto the tongue?
A. Between the shell and the “white of the egg”there is a small quantity of air, whichexpands in a stale egg, from theshrinking of the white.
A. Between the shell and the “white of the egg”there is a small quantity of air, whichexpands in a stale egg, from theshrinking of the white.
Q.Why does the expansion of air (at the end of an egg) make it feelwarmto the tongue?A. As air is a very bad conductor, themore air an egg contains, theless heat will be drawn from the tonguewhen it touches the shell.
Q.Why does the expansion of air (at the end of an egg) make it feelwarmto the tongue?
Q.Why does the expansion of air (at the end of an egg) make it feelwarmto the tongue?
A. As air is a very bad conductor, themore air an egg contains, theless heat will be drawn from the tonguewhen it touches the shell.
A. As air is a very bad conductor, themore air an egg contains, theless heat will be drawn from the tonguewhen it touches the shell.
Q.Why do ladiesfanthemselves in summer, to make theirfaces cool?A. The fanputs the air in motion, and makes it pass morerapidly over their face; and (as the temperature of theair is always lowerthan that of the humanface) each puff of aircarries off some portion of heatfrom the face.
Q.Why do ladiesfanthemselves in summer, to make theirfaces cool?
Q.Why do ladiesfanthemselves in summer, to make theirfaces cool?
A. The fanputs the air in motion, and makes it pass morerapidly over their face; and (as the temperature of theair is always lowerthan that of the humanface) each puff of aircarries off some portion of heatfrom the face.
A. The fanputs the air in motion, and makes it pass morerapidly over their face; and (as the temperature of theair is always lowerthan that of the humanface) each puff of aircarries off some portion of heatfrom the face.
Q.Doesfanningthe air make theairitselfcooler?A. No; fanning makes theair hotter and hotter.
Q.Doesfanningthe air make theairitselfcooler?
Q.Doesfanningthe air make theairitselfcooler?
A. No; fanning makes theair hotter and hotter.
A. No; fanning makes theair hotter and hotter.
Q.Why doesfanningthe air increase itsheat?A. By causing the air continually toabsorb heat from the human bodywhich it passes over.
Q.Why doesfanningthe air increase itsheat?
Q.Why doesfanningthe air increase itsheat?
A. By causing the air continually toabsorb heat from the human bodywhich it passes over.
A. By causing the air continually toabsorb heat from the human bodywhich it passes over.
Q.If fanning makes theair hotter, how can it make apersonfeelcooler?A. Fanning makes theair hotter, but theface cooler; because it keepstaking the heat out of the face, andgiving it to the air.
Q.If fanning makes theair hotter, how can it make apersonfeelcooler?
Q.If fanning makes theair hotter, how can it make apersonfeelcooler?
A. Fanning makes theair hotter, but theface cooler; because it keepstaking the heat out of the face, andgiving it to the air.
A. Fanning makes theair hotter, but theface cooler; because it keepstaking the heat out of the face, andgiving it to the air.
Q.Why isbroth cooledbyblowingit?A. The breath causes a rapidchange of airto pass over the broth; and (as the air is not so hot as the broth)it keeps absorbing heat, and thus makes the broth cooler and cooler.
Q.Why isbroth cooledbyblowingit?
Q.Why isbroth cooledbyblowingit?
A. The breath causes a rapidchange of airto pass over the broth; and (as the air is not so hot as the broth)it keeps absorbing heat, and thus makes the broth cooler and cooler.
A. The breath causes a rapidchange of airto pass over the broth; and (as the air is not so hot as the broth)it keeps absorbing heat, and thus makes the broth cooler and cooler.
Q.Would not the air absorb heat from the broth just as wellwithout blowing?A. No;air is a very bad conductor; unless, therefore,the change be rapid, the air nearest the surface of the brothwould soon become as hot as the broth itself.
Q.Would not the air absorb heat from the broth just as wellwithout blowing?
Q.Would not the air absorb heat from the broth just as wellwithout blowing?
A. No;air is a very bad conductor; unless, therefore,the change be rapid, the air nearest the surface of the brothwould soon become as hot as the broth itself.
A. No;air is a very bad conductor; unless, therefore,the change be rapid, the air nearest the surface of the brothwould soon become as hot as the broth itself.
Q.But would not the hot airpartwith its heat instantly to thecircumjacentair?A. No; not instantly. Air is so bad a conductor,that it parts with its heat very slowly: unless, therefore, the air be kept incontinual motion, it wouldcool the broth very slowly indeed.
Q.But would not the hot airpartwith its heat instantly to thecircumjacentair?
Q.But would not the hot airpartwith its heat instantly to thecircumjacentair?
A. No; not instantly. Air is so bad a conductor,that it parts with its heat very slowly: unless, therefore, the air be kept incontinual motion, it wouldcool the broth very slowly indeed.
A. No; not instantly. Air is so bad a conductor,that it parts with its heat very slowly: unless, therefore, the air be kept incontinual motion, it wouldcool the broth very slowly indeed.
Q.Why doeswindgenerally feelcool?A. Wind is only air in motion; and the more quickly theair passes over our body, the more rapidly itabsorbs the heattherefrom.
Q.Why doeswindgenerally feelcool?
Q.Why doeswindgenerally feelcool?
A. Wind is only air in motion; and the more quickly theair passes over our body, the more rapidly itabsorbs the heattherefrom.
A. Wind is only air in motion; and the more quickly theair passes over our body, the more rapidly itabsorbs the heattherefrom.
Q.Why doesair absorbheat morequicklyby being set inmotion?A. Because every fresh gust of airabsorbs a fresh portion of heat; and the more rapid thesuccession of gusts, the greater will be the quantity of air absorbed.
Q.Why doesair absorbheat morequicklyby being set inmotion?
Q.Why doesair absorbheat morequicklyby being set inmotion?
A. Because every fresh gust of airabsorbs a fresh portion of heat; and the more rapid thesuccession of gusts, the greater will be the quantity of air absorbed.
A. Because every fresh gust of airabsorbs a fresh portion of heat; and the more rapid thesuccession of gusts, the greater will be the quantity of air absorbed.
Q.If theairwerehotterthan our body, would thewindfeelcool?A. No; if the air werehotter than our body, it would feelinsufferably hot.
Q.If theairwerehotterthan our body, would thewindfeelcool?
Q.If theairwerehotterthan our body, would thewindfeelcool?
A. No; if the air werehotter than our body, it would feelinsufferably hot.
A. No; if the air werehotter than our body, it would feelinsufferably hot.
Q.Why would theairfeelintensely hot, if it werewarmerthan ourblood?A. Because then the wind wouldadd to the heat ofour body, instead ofdiminishing it.
Q.Why would theairfeelintensely hot, if it werewarmerthan ourblood?
Q.Why would theairfeelintensely hot, if it werewarmerthan ourblood?
A. Because then the wind wouldadd to the heat ofour body, instead ofdiminishing it.
A. Because then the wind wouldadd to the heat ofour body, instead ofdiminishing it.
Q.Is theair everashotas the humanbody?A. Not inthiscountry: in the hottest summer’s day, the air is always 10 or 12degrees cooler than the human body.
Q.Is theair everashotas the humanbody?
Q.Is theair everashotas the humanbody?
A. Not inthiscountry: in the hottest summer’s day, the air is always 10 or 12degrees cooler than the human body.
A. Not inthiscountry: in the hottest summer’s day, the air is always 10 or 12degrees cooler than the human body.
Q.Is theearthagood conductorof heat?A. No; the power ofconductingheat depends upon thecontinuity of matter; if the particles of which a thing is composed are notcontinuous, they have very little power toconduct heat.
Q.Is theearthagood conductorof heat?
Q.Is theearthagood conductorof heat?
A. No; the power ofconductingheat depends upon thecontinuity of matter; if the particles of which a thing is composed are notcontinuous, they have very little power toconduct heat.
A. No; the power ofconductingheat depends upon thecontinuity of matter; if the particles of which a thing is composed are notcontinuous, they have very little power toconduct heat.
Q.Why is the earth (belowthesurface)warmerinwinterthan the surface itself?A. Because the earth is abad conductor of heat; and, therefore (although the ground be frozen) the frost never penetratesabove an inch or two below the surface.
Q.Why is the earth (belowthesurface)warmerinwinterthan the surface itself?
Q.Why is the earth (belowthesurface)warmerinwinterthan the surface itself?
A. Because the earth is abad conductor of heat; and, therefore (although the ground be frozen) the frost never penetratesabove an inch or two below the surface.
A. Because the earth is abad conductor of heat; and, therefore (although the ground be frozen) the frost never penetratesabove an inch or two below the surface.
Q.Why is the earth (belowthesurface)coolerinsummerthan the surface itself?A. Because the earth is abad conductor of heat; and, therefore, (although the surface be scorched with the burning sun) the intense heat cannot penetrate tothe rootsof the plants and trees.
Q.Why is the earth (belowthesurface)coolerinsummerthan the surface itself?
Q.Why is the earth (belowthesurface)coolerinsummerthan the surface itself?
A. Because the earth is abad conductor of heat; and, therefore, (although the surface be scorched with the burning sun) the intense heat cannot penetrate tothe rootsof the plants and trees.
A. Because the earth is abad conductor of heat; and, therefore, (although the surface be scorched with the burning sun) the intense heat cannot penetrate tothe rootsof the plants and trees.
Q.Shew thewisdomofGodin making theearthabad conductor.A. If theheat and cold could penetrate the earth(as freely as the heat of a fire penetrates iron), the springs would be dried up in summer and frozen in winter, and all vegetation would perish.
Q.Shew thewisdomofGodin making theearthabad conductor.
Q.Shew thewisdomofGodin making theearthabad conductor.
A. If theheat and cold could penetrate the earth(as freely as the heat of a fire penetrates iron), the springs would be dried up in summer and frozen in winter, and all vegetation would perish.
A. If theheat and cold could penetrate the earth(as freely as the heat of a fire penetrates iron), the springs would be dried up in summer and frozen in winter, and all vegetation would perish.
Q.Why iswaterfrom aspringsocoolinsummer?A. As the earth is abad conductor, the burning rays of the sun can penetrate only a few inches below the surface; in consequence of which, thesprings of water are not affected.
Q.Why iswaterfrom aspringsocoolinsummer?
Q.Why iswaterfrom aspringsocoolinsummer?
A. As the earth is abad conductor, the burning rays of the sun can penetrate only a few inches below the surface; in consequence of which, thesprings of water are not affected.
A. As the earth is abad conductor, the burning rays of the sun can penetrate only a few inches below the surface; in consequence of which, thesprings of water are not affected.
Q.Why is itcoolunder ashadytree in a hot summer’s day?A. 1st—Because the overhanging foliagescreens off the rays of the sun:2ndly—As the rays of the sun are warded off,the air(beneath the tree)is not heated by the reflection of the earth: and3rdly—The leaves of trees, beingnon-conductors, allow no heat to penetrate through them.
Q.Why is itcoolunder ashadytree in a hot summer’s day?
Q.Why is itcoolunder ashadytree in a hot summer’s day?
A. 1st—Because the overhanging foliagescreens off the rays of the sun:2ndly—As the rays of the sun are warded off,the air(beneath the tree)is not heated by the reflection of the earth: and3rdly—The leaves of trees, beingnon-conductors, allow no heat to penetrate through them.
A. 1st—Because the overhanging foliagescreens off the rays of the sun:
2ndly—As the rays of the sun are warded off,the air(beneath the tree)is not heated by the reflection of the earth: and
3rdly—The leaves of trees, beingnon-conductors, allow no heat to penetrate through them.
Q.Why do thelaplanderswearskins, with thefur inwards?A. Thedry skinprevents thewind from penetrating to their body; and as thefurcontains aquantity of airbetween its hairs (which soonbecomes heated by the body) the Laplander is clad ina case of hot air, impervious to the cold and wind.
Q.Why do thelaplanderswearskins, with thefur inwards?
Q.Why do thelaplanderswearskins, with thefur inwards?
A. Thedry skinprevents thewind from penetrating to their body; and as thefurcontains aquantity of airbetween its hairs (which soonbecomes heated by the body) the Laplander is clad ina case of hot air, impervious to the cold and wind.
A. Thedry skinprevents thewind from penetrating to their body; and as thefurcontains aquantity of airbetween its hairs (which soonbecomes heated by the body) the Laplander is clad ina case of hot air, impervious to the cold and wind.
Q.Why does alinen shirtfeelcolderthan acotton one?A.Linen is a much better conductorthan cotton; and, therefore, (as soon as it touches the body)it more rapidly draws away the heat, and produces a sensation of cold.
Q.Why does alinen shirtfeelcolderthan acotton one?
Q.Why does alinen shirtfeelcolderthan acotton one?
A.Linen is a much better conductorthan cotton; and, therefore, (as soon as it touches the body)it more rapidly draws away the heat, and produces a sensation of cold.
A.Linen is a much better conductorthan cotton; and, therefore, (as soon as it touches the body)it more rapidly draws away the heat, and produces a sensation of cold.
Q.Why is theface cooledby wiping the temples with a finecambric handkerchief?A. The fine fibres of the cambric have astrong capillary attraction for moisture; and areexcellent conductors of heat: thus the moisture and heat areboth abstracted from the face, and a sensation of coolness is produced.“Capillary attraction,” i. e.the attraction of a thread or hair. The wick of a candle is wet with grease, because the melted tallow runs up the cotton from capillary attraction.
Q.Why is theface cooledby wiping the temples with a finecambric handkerchief?
Q.Why is theface cooledby wiping the temples with a finecambric handkerchief?
A. The fine fibres of the cambric have astrong capillary attraction for moisture; and areexcellent conductors of heat: thus the moisture and heat areboth abstracted from the face, and a sensation of coolness is produced.“Capillary attraction,” i. e.the attraction of a thread or hair. The wick of a candle is wet with grease, because the melted tallow runs up the cotton from capillary attraction.
A. The fine fibres of the cambric have astrong capillary attraction for moisture; and areexcellent conductors of heat: thus the moisture and heat areboth abstracted from the face, and a sensation of coolness is produced.
“Capillary attraction,” i. e.the attraction of a thread or hair. The wick of a candle is wet with grease, because the melted tallow runs up the cotton from capillary attraction.
Q.Why would not acottonhandkerchief do as well?A. The coarse fibres of cotton have much less capillary attraction, and arenothing like such good conductorsas linen: and, therefore, wiping the face with acotton handkerchief, increases the sensation of warmth.
Q.Why would not acottonhandkerchief do as well?
Q.Why would not acottonhandkerchief do as well?
A. The coarse fibres of cotton have much less capillary attraction, and arenothing like such good conductorsas linen: and, therefore, wiping the face with acotton handkerchief, increases the sensation of warmth.
A. The coarse fibres of cotton have much less capillary attraction, and arenothing like such good conductorsas linen: and, therefore, wiping the face with acotton handkerchief, increases the sensation of warmth.
Q.What is the difference betweenconductingheat, andabsorbingheat?A. Toconductheat, is totransmit itfrom one body to anotherthrough a conducting medium: toabsorbheat, is tosuck it up, as a sponge sucks up water.
Q.What is the difference betweenconductingheat, andabsorbingheat?
Q.What is the difference betweenconductingheat, andabsorbingheat?
A. Toconductheat, is totransmit itfrom one body to anotherthrough a conducting medium: toabsorbheat, is tosuck it up, as a sponge sucks up water.
A. Toconductheat, is totransmit itfrom one body to anotherthrough a conducting medium: toabsorbheat, is tosuck it up, as a sponge sucks up water.
Q.Give me an example.A.Black cloth absorbs, but does notconduct heat: thus, if black cloth be laid in the sun,it will absorb the raysvery rapidly; but ifone end of the black clothbe made hot, it would notconduct the heatto theotherend.
Q.Give me an example.
Q.Give me an example.
A.Black cloth absorbs, but does notconduct heat: thus, if black cloth be laid in the sun,it will absorb the raysvery rapidly; but ifone end of the black clothbe made hot, it would notconduct the heatto theotherend.
A.Black cloth absorbs, but does notconduct heat: thus, if black cloth be laid in the sun,it will absorb the raysvery rapidly; but ifone end of the black clothbe made hot, it would notconduct the heatto theotherend.
Q.Are goodconductorsof heat, goodabsorbersalso?A. No; everygood conductor of heatis abad absorber of it; andno good absorber of heatcan be agood conductoralso.
Q.Are goodconductorsof heat, goodabsorbersalso?
Q.Are goodconductorsof heat, goodabsorbersalso?
A. No; everygood conductor of heatis abad absorber of it; andno good absorber of heatcan be agood conductoralso.
A. No; everygood conductor of heatis abad absorber of it; andno good absorber of heatcan be agood conductoralso.
Q.Isirona goodabsorberof heat?A. No;iron is a good conductor, but a verybad absorberof heat.
Q.Isirona goodabsorberof heat?
Q.Isirona goodabsorberof heat?
A. No;iron is a good conductor, but a verybad absorberof heat.
A. No;iron is a good conductor, but a verybad absorberof heat.
Q.Why do thefenderandfire-irons(which lie upon it) remaincold, although they are before a good fire?A. Because the metal fender and fire-irons have verylittle capacity for absorbing heat; although they are soon made hot (by conduction), when placed incontactwith the hot fire or stove.
Q.Why do thefenderandfire-irons(which lie upon it) remaincold, although they are before a good fire?
Q.Why do thefenderandfire-irons(which lie upon it) remaincold, although they are before a good fire?
A. Because the metal fender and fire-irons have verylittle capacity for absorbing heat; although they are soon made hot (by conduction), when placed incontactwith the hot fire or stove.
A. Because the metal fender and fire-irons have verylittle capacity for absorbing heat; although they are soon made hot (by conduction), when placed incontactwith the hot fire or stove.
Q.Why does akettleboil faster, when the bottom and back arecoveredwithsoot?A. Theblack soot absorbs heatvery quickly from the fire, and the metalconducts it to the water.
Q.Why does akettleboil faster, when the bottom and back arecoveredwithsoot?
Q.Why does akettleboil faster, when the bottom and back arecoveredwithsoot?
A. Theblack soot absorbs heatvery quickly from the fire, and the metalconducts it to the water.
A. Theblack soot absorbs heatvery quickly from the fire, and the metalconducts it to the water.
Q.Why will not anew kettleboil so fast as anoldone?A. Because thebottom and sidesof a new kettle areclean and bright; but in anoldkettleare covered with soot.
Q.Why will not anew kettleboil so fast as anoldone?
Q.Why will not anew kettleboil so fast as anoldone?
A. Because thebottom and sidesof a new kettle areclean and bright; but in anoldkettleare covered with soot.
A. Because thebottom and sidesof a new kettle areclean and bright; but in anoldkettleare covered with soot.
Q.Why would thekettlebeslower boiling, if thebottomandbackwerecleanand bright?A.Brightmetal doesnot absorb heat, butreflect it(i. e. throw the heatbackagain); and as the heat isthrown off from the surface of bright metal, therefore, a new kettle is longer boiling.
Q.Why would thekettlebeslower boiling, if thebottomandbackwerecleanand bright?
Q.Why would thekettlebeslower boiling, if thebottomandbackwerecleanand bright?
A.Brightmetal doesnot absorb heat, butreflect it(i. e. throw the heatbackagain); and as the heat isthrown off from the surface of bright metal, therefore, a new kettle is longer boiling.
A.Brightmetal doesnot absorb heat, butreflect it(i. e. throw the heatbackagain); and as the heat isthrown off from the surface of bright metal, therefore, a new kettle is longer boiling.
Q.Why do we wearwhite linenand ablackouterdress, if we want to be warm?A. Theblack outer dressquicklyabsorbs heat from the sun, and conveys it to the body; and thewhite linen(being abadabsorbent) abstracts no heat from the warm body.
Q.Why do we wearwhite linenand ablackouterdress, if we want to be warm?
Q.Why do we wearwhite linenand ablackouterdress, if we want to be warm?
A. Theblack outer dressquicklyabsorbs heat from the sun, and conveys it to the body; and thewhite linen(being abadabsorbent) abstracts no heat from the warm body.
A. Theblack outer dressquicklyabsorbs heat from the sun, and conveys it to the body; and thewhite linen(being abadabsorbent) abstracts no heat from the warm body.
Q.Why do personswear whitedresses insummertime?A. Whitethrows off the heat of the sun by reflection, and is, therefore, a very bad absorbent of heat; in consequence of which, it never becomesso hot from the scorching sunas dark colours do.
Q.Why do personswear whitedresses insummertime?
Q.Why do personswear whitedresses insummertime?
A. Whitethrows off the heat of the sun by reflection, and is, therefore, a very bad absorbent of heat; in consequence of which, it never becomesso hot from the scorching sunas dark colours do.
A. Whitethrows off the heat of the sun by reflection, and is, therefore, a very bad absorbent of heat; in consequence of which, it never becomesso hot from the scorching sunas dark colours do.
Q.Why donotpersonswear whitedresses inwintertime?A.White will not absorb heat, like black and other dark colours; and, therefore,whitedresses arenot so warm as dark ones.
Q.Why donotpersonswear whitedresses inwintertime?
Q.Why donotpersonswear whitedresses inwintertime?
A.White will not absorb heat, like black and other dark colours; and, therefore,whitedresses arenot so warm as dark ones.
A.White will not absorb heat, like black and other dark colours; and, therefore,whitedresses arenot so warm as dark ones.
Q.Whatcoloursarewarmestfor dresses?A. Foroutsidegarmentsblack is the warmest, and then such colours asapproach nearest to black(as dark blue and green).White is the coldest colourfor external clothing.
Q.Whatcoloursarewarmestfor dresses?
Q.Whatcoloursarewarmestfor dresses?
A. Foroutsidegarmentsblack is the warmest, and then such colours asapproach nearest to black(as dark blue and green).White is the coldest colourfor external clothing.
A. Foroutsidegarmentsblack is the warmest, and then such colours asapproach nearest to black(as dark blue and green).White is the coldest colourfor external clothing.
Q.Why aredark colours(for external wear) so muchwarmerthanlight ones?A. Becausedark colours absorb heat from the sunmore abundantly thanlightones.
Q.Why aredark colours(for external wear) so muchwarmerthanlight ones?
Q.Why aredark colours(for external wear) so muchwarmerthanlight ones?
A. Becausedark colours absorb heat from the sunmore abundantly thanlightones.
A. Becausedark colours absorb heat from the sunmore abundantly thanlightones.
Q.How can you prove thatdarkcolours arewarmerthanlightones?A. If a piece ofblackcloth and a piece ofwhitewere laid upon snow,in a few hours theblack cloth will have melted the snow beneath; whereas thewhitecloth will have produced little orno effect upon it at all.N. B. The darker any colour is, the warmer it is, because it is a better absorbent of heat. The order may be thus arranged:—1. Black (warmest of all).—2. Violet.—3. Indigo.—4. Blue.—5. Green.—6. Red.—8. Yellow: and 9. White (coldest of all).
Q.How can you prove thatdarkcolours arewarmerthanlightones?
Q.How can you prove thatdarkcolours arewarmerthanlightones?
A. If a piece ofblackcloth and a piece ofwhitewere laid upon snow,in a few hours theblack cloth will have melted the snow beneath; whereas thewhitecloth will have produced little orno effect upon it at all.N. B. The darker any colour is, the warmer it is, because it is a better absorbent of heat. The order may be thus arranged:—1. Black (warmest of all).—2. Violet.—3. Indigo.—4. Blue.—5. Green.—6. Red.—8. Yellow: and 9. White (coldest of all).
A. If a piece ofblackcloth and a piece ofwhitewere laid upon snow,in a few hours theblack cloth will have melted the snow beneath; whereas thewhitecloth will have produced little orno effect upon it at all.
N. B. The darker any colour is, the warmer it is, because it is a better absorbent of heat. The order may be thus arranged:—1. Black (warmest of all).—2. Violet.—3. Indigo.—4. Blue.—5. Green.—6. Red.—8. Yellow: and 9. White (coldest of all).
Q.Why areblack kid glovessohotin summer time?A. 1st—Because theblack absorbs the solar heat: and2ndly—Thekidwill not allow the heat of the handto escape through the glove.
Q.Why areblack kid glovessohotin summer time?
Q.Why areblack kid glovessohotin summer time?
A. 1st—Because theblack absorbs the solar heat: and2ndly—Thekidwill not allow the heat of the handto escape through the glove.
A. 1st—Because theblack absorbs the solar heat: and
2ndly—Thekidwill not allow the heat of the handto escape through the glove.
Q.Why arelisle thread glovessocoolin summer time?A. 1st—Because threadabsorbs the perspiration of the hands: and2ndly—Itconducts away the heatof our hot hands.
Q.Why arelisle thread glovessocoolin summer time?
Q.Why arelisle thread glovessocoolin summer time?
A. 1st—Because threadabsorbs the perspiration of the hands: and2ndly—Itconducts away the heatof our hot hands.
A. 1st—Because threadabsorbs the perspiration of the hands: and
2ndly—Itconducts away the heatof our hot hands.
Q.Are Lisle thread glovesabsorbentsof heat?A. As Lisle thread gloves are generally of agrey or lilac colour, they donot absorb solar heat.
Q.Are Lisle thread glovesabsorbentsof heat?
Q.Are Lisle thread glovesabsorbentsof heat?
A. As Lisle thread gloves are generally of agrey or lilac colour, they donot absorb solar heat.
A. As Lisle thread gloves are generally of agrey or lilac colour, they donot absorb solar heat.
Q.Why is aplate-warmermade ofun-painted bright tin?A. Bright tin reflects (orthrows back)the heat, which issues from the fire in rays; and (by reflecting the heat upon the meat) assists greatly in roasting it.
Q.Why is aplate-warmermade ofun-painted bright tin?
Q.Why is aplate-warmermade ofun-painted bright tin?
A. Bright tin reflects (orthrows back)the heat, which issues from the fire in rays; and (by reflecting the heat upon the meat) assists greatly in roasting it.
A. Bright tin reflects (orthrows back)the heat, which issues from the fire in rays; and (by reflecting the heat upon the meat) assists greatly in roasting it.
Q.Why would not the tinreflectordo as well if it werepainted?A. If the tin reflector werepainted, it would be utterly spoiled, because it would thenabsorbheat, andnot reflect it at all. A plate-warmer should be keptvery clean, bright, and free from all scratches.
Q.Why would not the tinreflectordo as well if it werepainted?
Q.Why would not the tinreflectordo as well if it werepainted?
A. If the tin reflector werepainted, it would be utterly spoiled, because it would thenabsorbheat, andnot reflect it at all. A plate-warmer should be keptvery clean, bright, and free from all scratches.
A. If the tin reflector werepainted, it would be utterly spoiled, because it would thenabsorbheat, andnot reflect it at all. A plate-warmer should be keptvery clean, bright, and free from all scratches.
Q.Why should areflectorbe kept so verycleanand free fromscratches?A. If a reflector bespotted, dull, or scratched, it willabsorbheat, instead ofreflectingit; and, therefore, would be of no use whatsoever as areflector.
Q.Why should areflectorbe kept so verycleanand free fromscratches?
Q.Why should areflectorbe kept so verycleanand free fromscratches?
A. If a reflector bespotted, dull, or scratched, it willabsorbheat, instead ofreflectingit; and, therefore, would be of no use whatsoever as areflector.
A. If a reflector bespotted, dull, or scratched, it willabsorbheat, instead ofreflectingit; and, therefore, would be of no use whatsoever as areflector.
Q.Why doeshoar-frostremain ontombstones, long after it has melted from thegrassandgravel-walksof a church-yard?A. Tomb-stones beingwhite, willnot absorb heat, like the darker grass and gravel; and, therefore,the white tombstones(being so much colder)retain the hoar-frostafter it has melted from other things.
Q.Why doeshoar-frostremain ontombstones, long after it has melted from thegrassandgravel-walksof a church-yard?
Q.Why doeshoar-frostremain ontombstones, long after it has melted from thegrassandgravel-walksof a church-yard?
A. Tomb-stones beingwhite, willnot absorb heat, like the darker grass and gravel; and, therefore,the white tombstones(being so much colder)retain the hoar-frostafter it has melted from other things.
A. Tomb-stones beingwhite, willnot absorb heat, like the darker grass and gravel; and, therefore,the white tombstones(being so much colder)retain the hoar-frostafter it has melted from other things.
Q.If black absorbs heat, why have those who live inhotclimatesblack skins, and notwhiteskins (which would not absorb heat at all)?A. Though the black skin of the negroabsorbs heatmore plentifully than thewhite skin of a European, yet theblacknessprevents the sun fromblisteringorscorching it.
Q.If black absorbs heat, why have those who live inhotclimatesblack skins, and notwhiteskins (which would not absorb heat at all)?
Q.If black absorbs heat, why have those who live inhotclimatesblack skins, and notwhiteskins (which would not absorb heat at all)?
A. Though the black skin of the negroabsorbs heatmore plentifully than thewhite skin of a European, yet theblacknessprevents the sun fromblisteringorscorching it.
A. Though the black skin of the negroabsorbs heatmore plentifully than thewhite skin of a European, yet theblacknessprevents the sun fromblisteringorscorching it.
Q.How is it known that theblackcolour prevents the sun from eitherblisteringorscorchingthe skin?A. If you put awhite gloveonone hand, and ablack gloveonthe other(when the sun is burning hot), the hand with thewhiteglove will bescorched, butnot the other.
Q.How is it known that theblackcolour prevents the sun from eitherblisteringorscorchingthe skin?
Q.How is it known that theblackcolour prevents the sun from eitherblisteringorscorchingthe skin?
A. If you put awhite gloveonone hand, and ablack gloveonthe other(when the sun is burning hot), the hand with thewhiteglove will bescorched, butnot the other.
A. If you put awhite gloveonone hand, and ablack gloveonthe other(when the sun is burning hot), the hand with thewhiteglove will bescorched, butnot the other.
Q.Which hand willfeelthehotter?A. The hand with theblack glovewillfeelthehotter, but it will not bescorchedby the sun; whereas the hand with thewhite glove(though muchcooler) will beseverely scorched.
Q.Which hand willfeelthehotter?
Q.Which hand willfeelthehotter?
A. The hand with theblack glovewillfeelthehotter, but it will not bescorchedby the sun; whereas the hand with thewhite glove(though muchcooler) will beseverely scorched.
A. The hand with theblack glovewillfeelthehotter, but it will not bescorchedby the sun; whereas the hand with thewhite glove(though muchcooler) will beseverely scorched.
Q.Why does theblackskin of anegro never scorchorblisterwith the hot sun?A. Because theblack colour absorbsthe heat,—conveys itbelow the surfaceof the skin, and converts it tosensible heatandperspiration.
Q.Why does theblackskin of anegro never scorchorblisterwith the hot sun?
Q.Why does theblackskin of anegro never scorchorblisterwith the hot sun?
A. Because theblack colour absorbsthe heat,—conveys itbelow the surfaceof the skin, and converts it tosensible heatandperspiration.
A. Because theblack colour absorbsthe heat,—conveys itbelow the surfaceof the skin, and converts it tosensible heatandperspiration.
Q.Why does thewhite European skin blisterandscorchwhen exposed to the hot sun?A. Because thewhite will not absorbthe heat; and, therefore, the hot sunrests on the surface of the skin, and scorches it.
Q.Why does thewhite European skin blisterandscorchwhen exposed to the hot sun?
Q.Why does thewhite European skin blisterandscorchwhen exposed to the hot sun?
A. Because thewhite will not absorbthe heat; and, therefore, the hot sunrests on the surface of the skin, and scorches it.
A. Because thewhite will not absorbthe heat; and, therefore, the hot sunrests on the surface of the skin, and scorches it.
Q.Why has anegro black eyes?A. The black colour of a negro’s eyes defends them from the strong light of the tropical sun. If a negro’s eyes were notblack, the sun wouldscorch them, and every negro would be blind.
Q.Why has anegro black eyes?
Q.Why has anegro black eyes?
A. The black colour of a negro’s eyes defends them from the strong light of the tropical sun. If a negro’s eyes were notblack, the sun wouldscorch them, and every negro would be blind.
A. The black colour of a negro’s eyes defends them from the strong light of the tropical sun. If a negro’s eyes were notblack, the sun wouldscorch them, and every negro would be blind.
Q.Why iswater kept cooler(in summer time) in abright tin pot, than in anearthenone?A. Because bright metal willnot absorbthe heat of the summer sun, like anearthenvessel.
Q.Why iswater kept cooler(in summer time) in abright tin pot, than in anearthenone?
Q.Why iswater kept cooler(in summer time) in abright tin pot, than in anearthenone?
A. Because bright metal willnot absorbthe heat of the summer sun, like anearthenvessel.
A. Because bright metal willnot absorbthe heat of the summer sun, like anearthenvessel.
Q.Why isboilingwaterkept hotin abright tin vessellonger, than in an earthen one?A. Because bright tin will not suffer the heat of the boiling waterto escape in rays, as an earthen vessel does.
Q.Why isboilingwaterkept hotin abright tin vessellonger, than in an earthen one?
Q.Why isboilingwaterkept hotin abright tin vessellonger, than in an earthen one?
A. Because bright tin will not suffer the heat of the boiling waterto escape in rays, as an earthen vessel does.
A. Because bright tin will not suffer the heat of the boiling waterto escape in rays, as an earthen vessel does.
Q.What is meant byreflecting heat?A. To reflect heat, isto throw it back in raysfrom the surface of the reflecting body, towards the place from whence it came.
Q.What is meant byreflecting heat?
Q.What is meant byreflecting heat?
A. To reflect heat, isto throw it back in raysfrom the surface of the reflecting body, towards the place from whence it came.
A. To reflect heat, isto throw it back in raysfrom the surface of the reflecting body, towards the place from whence it came.
Q.What are thebest reflectorsof heat?A. Allbrightsurfaces, andlight colours.
Q.What are thebest reflectorsof heat?
Q.What are thebest reflectorsof heat?
A. Allbrightsurfaces, andlight colours.
A. Allbrightsurfaces, andlight colours.
Q.Aregood absorbersof heatgood reflectorsalso?A. No; those thingswhich absorb heat best, reflectheatworst; and thosewhich reflect heat worst, absorbitbest.
Q.Aregood absorbersof heatgood reflectorsalso?
Q.Aregood absorbersof heatgood reflectorsalso?
A. No; those thingswhich absorb heat best, reflectheatworst; and thosewhich reflect heat worst, absorbitbest.
A. No; those thingswhich absorb heat best, reflectheatworst; and thosewhich reflect heat worst, absorbitbest.
Q.Why are those things whichabsorb heatunable toreflectit?A. Because if any thingsucks in heatlike a sponge, it cannotthrow it offfrom its surface; and if any thingthrows off heatfrom its surface, it cannotdrink it in.
Q.Why are those things whichabsorb heatunable toreflectit?
Q.Why are those things whichabsorb heatunable toreflectit?
A. Because if any thingsucks in heatlike a sponge, it cannotthrow it offfrom its surface; and if any thingthrows off heatfrom its surface, it cannotdrink it in.
A. Because if any thingsucks in heatlike a sponge, it cannotthrow it offfrom its surface; and if any thingthrows off heatfrom its surface, it cannotdrink it in.
Q.Why arereflectorsalways made oflight-colouredand highlypolished metal?A. Becauselightcoloured andhighly polished metalmakes the best of all reflectors.
Q.Why arereflectorsalways made oflight-colouredand highlypolished metal?
Q.Why arereflectorsalways made oflight-colouredand highlypolished metal?
A. Becauselightcoloured andhighly polished metalmakes the best of all reflectors.
A. Becauselightcoloured andhighly polished metalmakes the best of all reflectors.
Q.Why do notplate-warmers blisterand scorch thewoodbehind?A. Because the bright tin frontthrows the heat of the fire back again, and will not allow it to penetrate to the wood behind.
Q.Why do notplate-warmers blisterand scorch thewoodbehind?
Q.Why do notplate-warmers blisterand scorch thewoodbehind?
A. Because the bright tin frontthrows the heat of the fire back again, and will not allow it to penetrate to the wood behind.
A. Because the bright tin frontthrows the heat of the fire back again, and will not allow it to penetrate to the wood behind.
Q.If metal be such an excellentconductorof heat, how can itreflectheat, or throw it off?A. Polished metal is aconductor of heat, only whenthat heat is communicated by actual contact; but whenever heatfalls upon bright metal in rays, it isreflected back again, and the metal remainsquite cool.
Q.If metal be such an excellentconductorof heat, how can itreflectheat, or throw it off?
Q.If metal be such an excellentconductorof heat, how can itreflectheat, or throw it off?
A. Polished metal is aconductor of heat, only whenthat heat is communicated by actual contact; but whenever heatfalls upon bright metal in rays, it isreflected back again, and the metal remainsquite cool.
A. Polished metal is aconductor of heat, only whenthat heat is communicated by actual contact; but whenever heatfalls upon bright metal in rays, it isreflected back again, and the metal remainsquite cool.
Q.What is meant by “heat falling upon metalin rays,” and not “by contact”?A. If a piece of tin were thrustintoa fire, it would bein actual contact with the fire; but if it beheld before a fire, the heat of the firefalls upon it in rays.
Q.What is meant by “heat falling upon metalin rays,” and not “by contact”?
Q.What is meant by “heat falling upon metalin rays,” and not “by contact”?
A. If a piece of tin were thrustintoa fire, it would bein actual contact with the fire; but if it beheld before a fire, the heat of the firefalls upon it in rays.
A. If a piece of tin were thrustintoa fire, it would bein actual contact with the fire; but if it beheld before a fire, the heat of the firefalls upon it in rays.
Q.What is the use of thetin screenorreflectorused inroasting?A. The tin reflectorthrows the heatof the fire back upon the meat; and, therefore, assists theprocess of roastingand helpsto keep the kitchen cool.
Q.What is the use of thetin screenorreflectorused inroasting?
Q.What is the use of thetin screenorreflectorused inroasting?
A. The tin reflectorthrows the heatof the fire back upon the meat; and, therefore, assists theprocess of roastingand helpsto keep the kitchen cool.
A. The tin reflectorthrows the heatof the fire back upon the meat; and, therefore, assists theprocess of roastingand helpsto keep the kitchen cool.
Q.How does a tinreflectortend to keep thekitchen cool?A. Because itconfines the heat to the hearth, and prevents it from being dispersed throughout the kitchen.
Q.How does a tinreflectortend to keep thekitchen cool?
Q.How does a tinreflectortend to keep thekitchen cool?
A. Because itconfines the heat to the hearth, and prevents it from being dispersed throughout the kitchen.
A. Because itconfines the heat to the hearth, and prevents it from being dispersed throughout the kitchen.
Q.Why does alamp glass diminishthesmokeof alamp?A. Asglass is a reflector, it reflects the heat of the lampback upon the flame; in consequence of which,less carbon escapes unconsumed(as smoke).
Q.Why does alamp glass diminishthesmokeof alamp?
Q.Why does alamp glass diminishthesmokeof alamp?
A. Asglass is a reflector, it reflects the heat of the lampback upon the flame; in consequence of which,less carbon escapes unconsumed(as smoke).
A. Asglass is a reflector, it reflects the heat of the lampback upon the flame; in consequence of which,less carbon escapes unconsumed(as smoke).
Q.Why areshoes hotterfor beingdusty?A. 1st—Because dust absorbs heat: and2ndly—As it destroys theblackness of our shoes, it prevents them fromthrowing off the heat of our feet in rays.
Q.Why areshoes hotterfor beingdusty?
Q.Why areshoes hotterfor beingdusty?
A. 1st—Because dust absorbs heat: and2ndly—As it destroys theblackness of our shoes, it prevents them fromthrowing off the heat of our feet in rays.
A. 1st—Because dust absorbs heat: and
2ndly—As it destroys theblackness of our shoes, it prevents them fromthrowing off the heat of our feet in rays.
Q.Why can we notseeinto theroadorstreet, when acandleis lighted in a room?A.Glass is a reflector; and, therefore, throws the rays of the candleback into the room, and thus prevents our seeing into the road or street.
Q.Why can we notseeinto theroadorstreet, when acandleis lighted in a room?
Q.Why can we notseeinto theroadorstreet, when acandleis lighted in a room?
A.Glass is a reflector; and, therefore, throws the rays of the candleback into the room, and thus prevents our seeing into the road or street.
A.Glass is a reflector; and, therefore, throws the rays of the candleback into the room, and thus prevents our seeing into the road or street.
Q.Why can persons in thedark streetsee into aroom(lighted by a candle or lamp)?A. The pupil of the eyeexpands greatly, when persons are in the dark; and, therefore, when any one in the dark street looks into a light room,his dilated pupilsees every thing distinctly.
Q.Why can persons in thedark streetsee into aroom(lighted by a candle or lamp)?
Q.Why can persons in thedark streetsee into aroom(lighted by a candle or lamp)?
A. The pupil of the eyeexpands greatly, when persons are in the dark; and, therefore, when any one in the dark street looks into a light room,his dilated pupilsees every thing distinctly.
A. The pupil of the eyeexpands greatly, when persons are in the dark; and, therefore, when any one in the dark street looks into a light room,his dilated pupilsees every thing distinctly.
Q.Why does it alwaysfreezeon thetopof amountain?A. Air is heatedby the reflection of the earth, and not by the rays of the sun; and, as there is no earth round a mountain-topto reflect heat, therefore, it remains intensely cold.
Q.Why does it alwaysfreezeon thetopof amountain?
Q.Why does it alwaysfreezeon thetopof amountain?
A. Air is heatedby the reflection of the earth, and not by the rays of the sun; and, as there is no earth round a mountain-topto reflect heat, therefore, it remains intensely cold.
A. Air is heatedby the reflection of the earth, and not by the rays of the sun; and, as there is no earth round a mountain-topto reflect heat, therefore, it remains intensely cold.
Q.What is meant byradiation?A. Radiation meansthe emission of rays: thus the sun radiates both light and heat; that is, it emitsrays of light and heatin all directions.
Q.What is meant byradiation?
Q.What is meant byradiation?
A. Radiation meansthe emission of rays: thus the sun radiates both light and heat; that is, it emitsrays of light and heatin all directions.
A. Radiation meansthe emission of rays: thus the sun radiates both light and heat; that is, it emitsrays of light and heatin all directions.
Q.When is heatradiatedfrom one body to another?A. When the two bodies areseparated by a non-conducting medium: thus the sunradiatesheat towards the earth, because theair comes between(which is a very bad conductor).
Q.When is heatradiatedfrom one body to another?
Q.When is heatradiatedfrom one body to another?
A. When the two bodies areseparated by a non-conducting medium: thus the sunradiatesheat towards the earth, because theair comes between(which is a very bad conductor).
A. When the two bodies areseparated by a non-conducting medium: thus the sunradiatesheat towards the earth, because theair comes between(which is a very bad conductor).
Q.Onwhatdoesradiation depend?A. On theroughnessof the radiating surface: thus if metal bescratched, its radiating power is increased, because theheat has more points to escape from.
Q.Onwhatdoesradiation depend?
Q.Onwhatdoesradiation depend?
A. On theroughnessof the radiating surface: thus if metal bescratched, its radiating power is increased, because theheat has more points to escape from.
A. On theroughnessof the radiating surface: thus if metal bescratched, its radiating power is increased, because theheat has more points to escape from.
Q.Does afire radiateheat?A. Yes; and becauseburning fuel emits rays of heat, therefore wefeel warmwhen we stand before a fire.
Q.Does afire radiateheat?
Q.Does afire radiateheat?
A. Yes; and becauseburning fuel emits rays of heat, therefore wefeel warmwhen we stand before a fire.
A. Yes; and becauseburning fuel emits rays of heat, therefore wefeel warmwhen we stand before a fire.
Q.Why does ourface feeluncomfortablyhot, when we approach afire?A. Because the fire radiates heat upon the face; which (not beingcovered) feels the effect immediately.
Q.Why does ourface feeluncomfortablyhot, when we approach afire?
Q.Why does ourface feeluncomfortablyhot, when we approach afire?
A. Because the fire radiates heat upon the face; which (not beingcovered) feels the effect immediately.
A. Because the fire radiates heat upon the face; which (not beingcovered) feels the effect immediately.
Q.Why does the fire catch thefacemore than therestof the body?A. Therestof the body iscovered with clothing, which (being abad conductorof heat) prevents the same suddenand rapid transmission of heat to the skin.
Q.Why does the fire catch thefacemore than therestof the body?
Q.Why does the fire catch thefacemore than therestof the body?
A. Therestof the body iscovered with clothing, which (being abad conductorof heat) prevents the same suddenand rapid transmission of heat to the skin.
A. Therestof the body iscovered with clothing, which (being abad conductorof heat) prevents the same suddenand rapid transmission of heat to the skin.
Q.Do those substances whichradiateheat,absorbheat also?A. Yes. Those substances whichradiate most, alsoabsorb most heat: and those whichradiate least, alsoabsorb the leastheat.
Q.Do those substances whichradiateheat,absorbheat also?
Q.Do those substances whichradiateheat,absorbheat also?
A. Yes. Those substances whichradiate most, alsoabsorb most heat: and those whichradiate least, alsoabsorb the leastheat.
A. Yes. Those substances whichradiate most, alsoabsorb most heat: and those whichradiate least, alsoabsorb the leastheat.
Q.Does any thingelseradiate heat,besidesthesunandfire?A. Yes;allthings radiate heat insomemeasure, butnot equally well.
Q.Does any thingelseradiate heat,besidesthesunandfire?
Q.Does any thingelseradiate heat,besidesthesunandfire?
A. Yes;allthings radiate heat insomemeasure, butnot equally well.
A. Yes;allthings radiate heat insomemeasure, butnot equally well.
Q.What thingsradiateheat thenext bestto the sun and fire?A. Alldullanddark substancesaregood radiatorsof heat; but alllightandpolished substancesarebad radiatorsof heat.
Q.What thingsradiateheat thenext bestto the sun and fire?
Q.What thingsradiateheat thenext bestto the sun and fire?
A. Alldullanddark substancesaregood radiatorsof heat; but alllightandpolished substancesarebad radiatorsof heat.
A. Alldullanddark substancesaregood radiatorsof heat; but alllightandpolished substancesarebad radiatorsof heat.
Q.Why does apolished metal tea-potmakebetter teathan a black earthen one?A. As polished metal is a verybad radiatorof heat, itkeeps the water hot much longer; and the hotter the water is, the better it “draws” the tea.
Q.Why does apolished metal tea-potmakebetter teathan a black earthen one?
Q.Why does apolished metal tea-potmakebetter teathan a black earthen one?
A. As polished metal is a verybad radiatorof heat, itkeeps the water hot much longer; and the hotter the water is, the better it “draws” the tea.
A. As polished metal is a verybad radiatorof heat, itkeeps the water hot much longer; and the hotter the water is, the better it “draws” the tea.
Q.Why will not adull black tea-potmake good tea?A. Because the heat of the waterflies off so quicklythrough the dull black surface of the tea-pot, that thewater is rapidly cooled, and will not “draw” the tea.
Q.Why will not adull black tea-potmake good tea?
Q.Why will not adull black tea-potmake good tea?
A. Because the heat of the waterflies off so quicklythrough the dull black surface of the tea-pot, that thewater is rapidly cooled, and will not “draw” the tea.
A. Because the heat of the waterflies off so quicklythrough the dull black surface of the tea-pot, that thewater is rapidly cooled, and will not “draw” the tea.
Q.Do not pensioners, and most aged cottagers, prefer the littleblack earthen tea-potto the brightmetalone?A. Yes; because theyset it on the hob “to draw;”in which case, the littleblack tea-potwill make thebest tea.
Q.Do not pensioners, and most aged cottagers, prefer the littleblack earthen tea-potto the brightmetalone?
Q.Do not pensioners, and most aged cottagers, prefer the littleblack earthen tea-potto the brightmetalone?
A. Yes; because theyset it on the hob “to draw;”in which case, the littleblack tea-potwill make thebest tea.
A. Yes; because theyset it on the hob “to draw;”in which case, the littleblack tea-potwill make thebest tea.
Q.Why will ablack tea-potmake better tea than a bright metal one, if it be set upon thehobtodraw?A. Because the black tea-pot willabsorb heat plentifullyfrom the fire, and keep the waterboiling hot: whereas, a brightmetaltea-pot (set upon the hob) wouldthrow offthe heat byreflection.
Q.Why will ablack tea-potmake better tea than a bright metal one, if it be set upon thehobtodraw?
Q.Why will ablack tea-potmake better tea than a bright metal one, if it be set upon thehobtodraw?
A. Because the black tea-pot willabsorb heat plentifullyfrom the fire, and keep the waterboiling hot: whereas, a brightmetaltea-pot (set upon the hob) wouldthrow offthe heat byreflection.
A. Because the black tea-pot willabsorb heat plentifullyfrom the fire, and keep the waterboiling hot: whereas, a brightmetaltea-pot (set upon the hob) wouldthrow offthe heat byreflection.
Q.Then sometimes ablack earthentea-pot is the best, and sometimes a brightmetalone?A. Yes; when the tea-pot isset on the hob “to draw,”the blackearthis thebest, because itabsorbs heat: but when the tea-pot isnotset on the hob, the brightmetalis thebest, because itradiates heat very slowly, and thereforekeeps the water hot.
Q.Then sometimes ablack earthentea-pot is the best, and sometimes a brightmetalone?
Q.Then sometimes ablack earthentea-pot is the best, and sometimes a brightmetalone?
A. Yes; when the tea-pot isset on the hob “to draw,”the blackearthis thebest, because itabsorbs heat: but when the tea-pot isnotset on the hob, the brightmetalis thebest, because itradiates heat very slowly, and thereforekeeps the water hot.
A. Yes; when the tea-pot isset on the hob “to draw,”the blackearthis thebest, because itabsorbs heat: but when the tea-pot isnotset on the hob, the brightmetalis thebest, because itradiates heat very slowly, and thereforekeeps the water hot.
Q.Why does asaucepanwhich has beenused, boilquickerthan anew one?A. Because the bottom and back arecovered with soot; and theblack sootrapidlyabsorbs the heatof the glowing coals.
Q.Why does asaucepanwhich has beenused, boilquickerthan anew one?
Q.Why does asaucepanwhich has beenused, boilquickerthan anew one?
A. Because the bottom and back arecovered with soot; and theblack sootrapidlyabsorbs the heatof the glowing coals.
A. Because the bottom and back arecovered with soot; and theblack sootrapidlyabsorbs the heatof the glowing coals.
Q.Why should thefrontandlidof asaucepanbe clean andbright?A. As they do not come in contact with the fire, they cannotabsorb heat; and (being bright) they will not sufferthe heat to escapeby radiation.
Q.Why should thefrontandlidof asaucepanbe clean andbright?
Q.Why should thefrontandlidof asaucepanbe clean andbright?
A. As they do not come in contact with the fire, they cannotabsorb heat; and (being bright) they will not sufferthe heat to escapeby radiation.
A. As they do not come in contact with the fire, they cannotabsorb heat; and (being bright) they will not sufferthe heat to escapeby radiation.
Q.In what state should asaucepanbe, in order that it mayboil quickly?A. All those parts whichcome in contact with the fireshould be covered withsoot, to absorb heat; but all therestof the saucepan should be asbright as possible, to prevent theescape of heatby radiation.
Q.In what state should asaucepanbe, in order that it mayboil quickly?
Q.In what state should asaucepanbe, in order that it mayboil quickly?
A. All those parts whichcome in contact with the fireshould be covered withsoot, to absorb heat; but all therestof the saucepan should be asbright as possible, to prevent theescape of heatby radiation.
A. All those parts whichcome in contact with the fireshould be covered withsoot, to absorb heat; but all therestof the saucepan should be asbright as possible, to prevent theescape of heatby radiation.
Q.Why is it said that “Saturday’s kettle boilsthefastest?”A. Because on Saturday thefrontandtopof the kettle are generallycleanedandpolished;but thebottomandbackof the kettle arenevercleaned.
Q.Why is it said that “Saturday’s kettle boilsthefastest?”
Q.Why is it said that “Saturday’s kettle boilsthefastest?”
A. Because on Saturday thefrontandtopof the kettle are generallycleanedandpolished;but thebottomandbackof the kettle arenevercleaned.
A. Because on Saturday thefrontandtopof the kettle are generallycleanedandpolished;but thebottomandbackof the kettle arenevercleaned.
Q.Why shouldnotthebottomandbackof a kettle becleanedand polished?A. Because theycome in contact with the fire, and (while they are covered with black soot)absorb heat freelyfrom the burning coals.
Q.Why shouldnotthebottomandbackof a kettle becleanedand polished?
Q.Why shouldnotthebottomandbackof a kettle becleanedand polished?
A. Because theycome in contact with the fire, and (while they are covered with black soot)absorb heat freelyfrom the burning coals.
A. Because theycome in contact with the fire, and (while they are covered with black soot)absorb heat freelyfrom the burning coals.
Q.Why should thefrontandtopof a kettle becleanand well polished?A. Because polished metalwill not radiate heat; and, therefore, (while the front and top of the kettle are well polished)the heat is kept in, and not suffered to escape by radiation.
Q.Why should thefrontandtopof a kettle becleanand well polished?
Q.Why should thefrontandtopof a kettle becleanand well polished?
A. Because polished metalwill not radiate heat; and, therefore, (while the front and top of the kettle are well polished)the heat is kept in, and not suffered to escape by radiation.
A. Because polished metalwill not radiate heat; and, therefore, (while the front and top of the kettle are well polished)the heat is kept in, and not suffered to escape by radiation.
Q.Why is theinsideof akettleandsaucepan white?A.White will not radiate heat: if, therefore, the inside of a boiler bewhite, the liquor in it iskept hot much longer.
Q.Why is theinsideof akettleandsaucepan white?
Q.Why is theinsideof akettleandsaucepan white?
A.White will not radiate heat: if, therefore, the inside of a boiler bewhite, the liquor in it iskept hot much longer.
A.White will not radiate heat: if, therefore, the inside of a boiler bewhite, the liquor in it iskept hot much longer.
Q.Why is thebottomof akettlenearlycold, when thewaterisboiling hot?A. Black soot is a verybad conductor of heat; and, therefore, the heat of the boiling water is some considerable time, before it getsthrough the sootwhich adheres to the bottom of the kettle.
Q.Why is thebottomof akettlenearlycold, when thewaterisboiling hot?
Q.Why is thebottomof akettlenearlycold, when thewaterisboiling hot?
A. Black soot is a verybad conductor of heat; and, therefore, the heat of the boiling water is some considerable time, before it getsthrough the sootwhich adheres to the bottom of the kettle.
A. Black soot is a verybad conductor of heat; and, therefore, the heat of the boiling water is some considerable time, before it getsthrough the sootwhich adheres to the bottom of the kettle.