Q.Why does themoonappearlargerat herrisingandsetting, than when above our heads?A. Because the rays pass throughmore of the vapoury atmospherewhich surroundsthe earth; and this vapoury atmospheremagnifiesthe moon, just like a magnifying glass.
Q.Why does themoonappearlargerat herrisingandsetting, than when above our heads?
Q.Why does themoonappearlargerat herrisingandsetting, than when above our heads?
A. Because the rays pass throughmore of the vapoury atmospherewhich surroundsthe earth; and this vapoury atmospheremagnifiesthe moon, just like a magnifying glass.
A. Because the rays pass throughmore of the vapoury atmospherewhich surroundsthe earth; and this vapoury atmospheremagnifiesthe moon, just like a magnifying glass.
Q.Why docats rubtheirearswhen it is likely to rain?A. Either because theair is full of vapour, and its humidity (piercing between the hair of the cat)produces an itching sensation; or more probably, because the air isovercharged with electricity.
Q.Why docats rubtheirearswhen it is likely to rain?
Q.Why docats rubtheirearswhen it is likely to rain?
A. Either because theair is full of vapour, and its humidity (piercing between the hair of the cat)produces an itching sensation; or more probably, because the air isovercharged with electricity.
A. Either because theair is full of vapour, and its humidity (piercing between the hair of the cat)produces an itching sensation; or more probably, because the air isovercharged with electricity.
Q.How can theelectricityof air produce a sensation ofitching?A. If theairis overcharged with electricity, thehair of the catis overcharged also; and this makes her feelas if she were covered with cobwebs.
Q.How can theelectricityof air produce a sensation ofitching?
Q.How can theelectricityof air produce a sensation ofitching?
A. If theairis overcharged with electricity, thehair of the catis overcharged also; and this makes her feelas if she were covered with cobwebs.
A. If theairis overcharged with electricity, thehair of the catis overcharged also; and this makes her feelas if she were covered with cobwebs.
Q.Why does thecatkeeprubbingherself?A. Herhair will not lie smooth, but has a perpetual tendency to becometurgid and ruffled; so the cat keeps rubbing her coat and ears, tosmooth the hair down, and brush away the feeling of cobwebs.
Q.Why does thecatkeeprubbingherself?
Q.Why does thecatkeeprubbingherself?
A. Herhair will not lie smooth, but has a perpetual tendency to becometurgid and ruffled; so the cat keeps rubbing her coat and ears, tosmooth the hair down, and brush away the feeling of cobwebs.
A. Herhair will not lie smooth, but has a perpetual tendency to becometurgid and ruffled; so the cat keeps rubbing her coat and ears, tosmooth the hair down, and brush away the feeling of cobwebs.
Q.Why do ourheadsandskinitch before rain?A. Probably because theair is overcharged with electricity; and, therefore, a sensation (like that of cobwebs)irritates the skin, and produces an itching.
Q.Why do ourheadsandskinitch before rain?
Q.Why do ourheadsandskinitch before rain?
A. Probably because theair is overcharged with electricity; and, therefore, a sensation (like that of cobwebs)irritates the skin, and produces an itching.
A. Probably because theair is overcharged with electricity; and, therefore, a sensation (like that of cobwebs)irritates the skin, and produces an itching.
Q.Why do weheardistant CLOCKS more distinctly when rain is near at hand?A. Because theair is filled with vapour, and water is a better conductor of sound than dry air.
Q.Why do weheardistant CLOCKS more distinctly when rain is near at hand?
Q.Why do weheardistant CLOCKS more distinctly when rain is near at hand?
A. Because theair is filled with vapour, and water is a better conductor of sound than dry air.
A. Because theair is filled with vapour, and water is a better conductor of sound than dry air.
Q.Why do we hearchurch-bellsfurther, just previous to rain?A. Because theair is filled with vapour, and vapour is a better conductor of sound than dry air.
Q.Why do we hearchurch-bellsfurther, just previous to rain?
Q.Why do we hearchurch-bellsfurther, just previous to rain?
A. Because theair is filled with vapour, and vapour is a better conductor of sound than dry air.
A. Because theair is filled with vapour, and vapour is a better conductor of sound than dry air.
Q.Why dodoors swell, whenrainis at hand?A. Because theair is filled with vapour, which (penetrating into the pores of the wood)forces the parts further apart, and swells the door.
Q.Why dodoors swell, whenrainis at hand?
Q.Why dodoors swell, whenrainis at hand?
A. Because theair is filled with vapour, which (penetrating into the pores of the wood)forces the parts further apart, and swells the door.
A. Because theair is filled with vapour, which (penetrating into the pores of the wood)forces the parts further apart, and swells the door.
Q.Why dodoors shrinkindryweather?A. Because themoisture is absorbed from the wood; and, as the particles arebrought closer together, the size of the door islessened, (or in other words, thewood shrinks).
Q.Why dodoors shrinkindryweather?
Q.Why dodoors shrinkindryweather?
A. Because themoisture is absorbed from the wood; and, as the particles arebrought closer together, the size of the door islessened, (or in other words, thewood shrinks).
A. Because themoisture is absorbed from the wood; and, as the particles arebrought closer together, the size of the door islessened, (or in other words, thewood shrinks).
Q.Why is theairfilled with offensivesmellsprevious to a comingrain?A. Because the volatile parts, (which rise from dunghills, sewers, &c.), beingladen with vapour, are unable to rise so readily, as when they are rarefied by a bright sun.
Q.Why is theairfilled with offensivesmellsprevious to a comingrain?
Q.Why is theairfilled with offensivesmellsprevious to a comingrain?
A. Because the volatile parts, (which rise from dunghills, sewers, &c.), beingladen with vapour, are unable to rise so readily, as when they are rarefied by a bright sun.
A. Because the volatile parts, (which rise from dunghills, sewers, &c.), beingladen with vapour, are unable to rise so readily, as when they are rarefied by a bright sun.
Q.Why doflowerssmellsweeterandstrongerjust previous torain?A. Because the volatile parts (which constitute theperfumeof flowers) areladen with vapour; and (being unable to rise) are confined to the lower regions of the air.
Q.Why doflowerssmellsweeterandstrongerjust previous torain?
Q.Why doflowerssmellsweeterandstrongerjust previous torain?
A. Because the volatile parts (which constitute theperfumeof flowers) areladen with vapour; and (being unable to rise) are confined to the lower regions of the air.
A. Because the volatile parts (which constitute theperfumeof flowers) areladen with vapour; and (being unable to rise) are confined to the lower regions of the air.
Q.Why dohorsesand other animals stretch out their necks, andsnuffup theair, just previous to a fall ofrain?A. Because theysmell the odour of plants and hay, and delight to snuff in their fragrance.
Q.Why dohorsesand other animals stretch out their necks, andsnuffup theair, just previous to a fall ofrain?
Q.Why dohorsesand other animals stretch out their necks, andsnuffup theair, just previous to a fall ofrain?
A. Because theysmell the odour of plants and hay, and delight to snuff in their fragrance.
A. Because theysmell the odour of plants and hay, and delight to snuff in their fragrance.
Q.Why doessmoke fallwhenrainis at hand?A. The air being lessdensein wet weather,cannot buoy up smokeso readily, as whenmore dry and heavy.
Q.Why doessmoke fallwhenrainis at hand?
Q.Why doessmoke fallwhenrainis at hand?
A. The air being lessdensein wet weather,cannot buoy up smokeso readily, as whenmore dry and heavy.
A. The air being lessdensein wet weather,cannot buoy up smokeso readily, as whenmore dry and heavy.
Q.Why doswallows fly lowwhenrainis at hand?A. Because theinsects(of which they are in pursuit)have fled from the cold upper regions of the air, to thewarmair near the earth: and as theirfood is low, the swallowsfly low.
Q.Why doswallows fly lowwhenrainis at hand?
Q.Why doswallows fly lowwhenrainis at hand?
A. Because theinsects(of which they are in pursuit)have fled from the cold upper regions of the air, to thewarmair near the earth: and as theirfood is low, the swallowsfly low.
A. Because theinsects(of which they are in pursuit)have fled from the cold upper regions of the air, to thewarmair near the earth: and as theirfood is low, the swallowsfly low.
Q.Why do theseinsectsseek the lower regions of the air inwetweather, more than infineweather?A. Because they are forced downward, by some current of cold air whichdrives them down.
Q.Why do theseinsectsseek the lower regions of the air inwetweather, more than infineweather?
Q.Why do theseinsectsseek the lower regions of the air inwetweather, more than infineweather?
A. Because they are forced downward, by some current of cold air whichdrives them down.
A. Because they are forced downward, by some current of cold air whichdrives them down.
Q.Why does adownwardcurrent ofcold airbringrain?A. Because itcondenses the warm vapour; which then descends in rain.
Q.Why does adownwardcurrent ofcold airbringrain?
Q.Why does adownwardcurrent ofcold airbringrain?
A. Because itcondenses the warm vapour; which then descends in rain.
A. Because itcondenses the warm vapour; which then descends in rain.
Q.The proverb says, “a single magpiein spring,foul weatherwill bring:” why is this the case?A. In cold stormy weather,one magpie alonewill leave its warm snug nestin search of food, while the other stays with theeggs or young ones; but infine mildweather (when their brood will not be injured by cold)both the magpies will fly out together.
Q.The proverb says, “a single magpiein spring,foul weatherwill bring:” why is this the case?
Q.The proverb says, “a single magpiein spring,foul weatherwill bring:” why is this the case?
A. In cold stormy weather,one magpie alonewill leave its warm snug nestin search of food, while the other stays with theeggs or young ones; but infine mildweather (when their brood will not be injured by cold)both the magpies will fly out together.
A. In cold stormy weather,one magpie alonewill leave its warm snug nestin search of food, while the other stays with theeggs or young ones; but infine mildweather (when their brood will not be injured by cold)both the magpies will fly out together.
Q.Why is itunluckyforanglersto see asingle magpiein spring?A. Because whenmagpies fly abroad singly, the weather is cold and stormy; but whenboth birds fly out together, the weather iswarm and mild, which isfavourable for fishing.
Q.Why is itunluckyforanglersto see asingle magpiein spring?
Q.Why is itunluckyforanglersto see asingle magpiein spring?
A. Because whenmagpies fly abroad singly, the weather is cold and stormy; but whenboth birds fly out together, the weather iswarm and mild, which isfavourable for fishing.
A. Because whenmagpies fly abroad singly, the weather is cold and stormy; but whenboth birds fly out together, the weather iswarm and mild, which isfavourable for fishing.
Q.Why dosea gullsfly about theseainfineweather?A. Because theylive upon fish, which are found near thesurface of the sea in fine weather.
Q.Why dosea gullsfly about theseainfineweather?
Q.Why dosea gullsfly about theseainfineweather?
A. Because theylive upon fish, which are found near thesurface of the sea in fine weather.
A. Because theylive upon fish, which are found near thesurface of the sea in fine weather.
Q.Why may we expectstormy rains, whensea gullsassemble on the land?A. Because the fish (on which they live) leave thesurfaceof the sea in stormy weather, andgo down too deep for the gulls to get at them; they are obliged, therefore, to feed on theworms and larvæwhich are driven out of thegroundat such times.
Q.Why may we expectstormy rains, whensea gullsassemble on the land?
Q.Why may we expectstormy rains, whensea gullsassemble on the land?
A. Because the fish (on which they live) leave thesurfaceof the sea in stormy weather, andgo down too deep for the gulls to get at them; they are obliged, therefore, to feed on theworms and larvæwhich are driven out of thegroundat such times.
A. Because the fish (on which they live) leave thesurfaceof the sea in stormy weather, andgo down too deep for the gulls to get at them; they are obliged, therefore, to feed on theworms and larvæwhich are driven out of thegroundat such times.
Q.Why does thepetrelalways fly to theseaduring a storm?A. Because the petrellives upon sea insects, which are always to be found in abundanceabout the spray of swelling waves.(The Petrel is a bird of the duck-kind, which lives in theopen sea. They run on the top of the sea, and are called Petrels, or rather Peter-els, from “St. Peter,” in allusion to his walking on the sea, to go to Jesus.)
Q.Why does thepetrelalways fly to theseaduring a storm?
Q.Why does thepetrelalways fly to theseaduring a storm?
A. Because the petrellives upon sea insects, which are always to be found in abundanceabout the spray of swelling waves.(The Petrel is a bird of the duck-kind, which lives in theopen sea. They run on the top of the sea, and are called Petrels, or rather Peter-els, from “St. Peter,” in allusion to his walking on the sea, to go to Jesus.)
A. Because the petrellives upon sea insects, which are always to be found in abundanceabout the spray of swelling waves.
(The Petrel is a bird of the duck-kind, which lives in theopen sea. They run on the top of the sea, and are called Petrels, or rather Peter-els, from “St. Peter,” in allusion to his walking on the sea, to go to Jesus.)
Q.Why docandlesandlamps spirtwhenrainis at hand?A. Because theair is filled with vapour, and the humiditypenetrates the wick; where (being formed intosteam) it expands suddenly, and produces a little explosion.
Q.Why docandlesandlamps spirtwhenrainis at hand?
Q.Why docandlesandlamps spirtwhenrainis at hand?
A. Because theair is filled with vapour, and the humiditypenetrates the wick; where (being formed intosteam) it expands suddenly, and produces a little explosion.
A. Because theair is filled with vapour, and the humiditypenetrates the wick; where (being formed intosteam) it expands suddenly, and produces a little explosion.
Q.Why does adropofwatersometimesrollalong a piece of hot iron without leaving the least trace?A. If the iron bevery hot indeed, thebottomof the drop is turned intovapour, before the drop can evaporate; and the vapour thus formedbuoys the drop up, without allowing it to touch the iron at all.
Q.Why does adropofwatersometimesrollalong a piece of hot iron without leaving the least trace?
Q.Why does adropofwatersometimesrollalong a piece of hot iron without leaving the least trace?
A. If the iron bevery hot indeed, thebottomof the drop is turned intovapour, before the drop can evaporate; and the vapour thus formedbuoys the drop up, without allowing it to touch the iron at all.
A. If the iron bevery hot indeed, thebottomof the drop is turned intovapour, before the drop can evaporate; and the vapour thus formedbuoys the drop up, without allowing it to touch the iron at all.
Q.Why does itroll?A. Thecurrent of air(which is always passing over the heated surface)drives it along.
Q.Why does itroll?
Q.Why does itroll?
A. Thecurrent of air(which is always passing over the heated surface)drives it along.
A. Thecurrent of air(which is always passing over the heated surface)drives it along.
Q.Why does alaundressput a littlesalivaon anironing-boxto know if it be hot enough?A. If the salivasticks to the box andis evaporated, the box isnothot enough; but if the salivaruns along the box, itis.
Q.Why does alaundressput a littlesalivaon anironing-boxto know if it be hot enough?
Q.Why does alaundressput a littlesalivaon anironing-boxto know if it be hot enough?
A. If the salivasticks to the box andis evaporated, the box isnothot enough; but if the salivaruns along the box, itis.
A. If the salivasticks to the box andis evaporated, the box isnothot enough; but if the salivaruns along the box, itis.
Q.Why is thebox hotterif the salivaruns along the box, than if it adheres to it till it is evaporated?A. If the salivaruns along the box, the iron is hot enough toconvert the bottom of the dropof spittle intovapour; but if the salivawill not roll, the box isnothot enough to convert the bottom of the drop of spittle into vapour.
Q.Why is thebox hotterif the salivaruns along the box, than if it adheres to it till it is evaporated?
Q.Why is thebox hotterif the salivaruns along the box, than if it adheres to it till it is evaporated?
A. If the salivaruns along the box, the iron is hot enough toconvert the bottom of the dropof spittle intovapour; but if the salivawill not roll, the box isnothot enough to convert the bottom of the drop of spittle into vapour.
A. If the salivaruns along the box, the iron is hot enough toconvert the bottom of the dropof spittle intovapour; but if the salivawill not roll, the box isnothot enough to convert the bottom of the drop of spittle into vapour.
Q.What is meant byevaporation?A. The dissipation of liquid by its beingconverted into vapour.
Q.What is meant byevaporation?
Q.What is meant byevaporation?
A. The dissipation of liquid by its beingconverted into vapour.
A. The dissipation of liquid by its beingconverted into vapour.
Q.Whateffectsare produced by evaporation?A. Theliquid vaporized absorbs heatfrom the body whence it issues; and thebody deprived of the liquidby evaporation,loses heatthereby.
Q.Whateffectsare produced by evaporation?
Q.Whateffectsare produced by evaporation?
A. Theliquid vaporized absorbs heatfrom the body whence it issues; and thebody deprived of the liquidby evaporation,loses heatthereby.
A. Theliquid vaporized absorbs heatfrom the body whence it issues; and thebody deprived of the liquidby evaporation,loses heatthereby.
Q.If youwetyourfingerin your mouth, and hold it up in the air, why does itfeel cold?A. The saliva quicklyevaporates; and (as it evaporates)absorbs heat from the finger, which makes it feel cold.
Q.If youwetyourfingerin your mouth, and hold it up in the air, why does itfeel cold?
Q.If youwetyourfingerin your mouth, and hold it up in the air, why does itfeel cold?
A. The saliva quicklyevaporates; and (as it evaporates)absorbs heat from the finger, which makes it feel cold.
A. The saliva quicklyevaporates; and (as it evaporates)absorbs heat from the finger, which makes it feel cold.
Q.If youbatheyourtempleswith ether, why does it allayinflammationand feverish heat?A. Ether very rapidlyevaporates; and (as it evaporates)absorbs heat from the burning head, producing a sensation of cold.
Q.If youbatheyourtempleswith ether, why does it allayinflammationand feverish heat?
Q.If youbatheyourtempleswith ether, why does it allayinflammationand feverish heat?
A. Ether very rapidlyevaporates; and (as it evaporates)absorbs heat from the burning head, producing a sensation of cold.
A. Ether very rapidlyevaporates; and (as it evaporates)absorbs heat from the burning head, producing a sensation of cold.
Q.Why isetherbetter for this purpose thanwater?A. Because it requiresless heat to convert it into vapour; and therefore it evaporates much morequickly.(Ether is converted into steam with 104degs.of heat, but water requires 212degs.of heat to convert it into steam.)
Q.Why isetherbetter for this purpose thanwater?
Q.Why isetherbetter for this purpose thanwater?
A. Because it requiresless heat to convert it into vapour; and therefore it evaporates much morequickly.(Ether is converted into steam with 104degs.of heat, but water requires 212degs.of heat to convert it into steam.)
A. Because it requiresless heat to convert it into vapour; and therefore it evaporates much morequickly.
(Ether is converted into steam with 104degs.of heat, but water requires 212degs.of heat to convert it into steam.)
Q.Why doesethervery greatlyrelieveascaldorburn?A. Because itevaporates very rapidly; and (while it is converted into vapour)carries off the heat of the burn.
Q.Why doesethervery greatlyrelieveascaldorburn?
Q.Why doesethervery greatlyrelieveascaldorburn?
A. Because itevaporates very rapidly; and (while it is converted into vapour)carries off the heat of the burn.
A. Because itevaporates very rapidly; and (while it is converted into vapour)carries off the heat of the burn.
Q.Why do wefeelsocoldwhen we havewet feetorclothes?A. As the wet of our shoes or clothesevaporates, itkeeps absorbing heat from the body, which makes it feel cold.
Q.Why do wefeelsocoldwhen we havewet feetorclothes?
Q.Why do wefeelsocoldwhen we havewet feetorclothes?
A. As the wet of our shoes or clothesevaporates, itkeeps absorbing heat from the body, which makes it feel cold.
A. As the wet of our shoes or clothesevaporates, itkeeps absorbing heat from the body, which makes it feel cold.
Q.Why dowet feetorclothesgive us “cold?”A. Because the evaporationabsorbs heat from the body so abundantly, that it islowered below its natural standard; and therefore health is injured.
Q.Why dowet feetorclothesgive us “cold?”
Q.Why dowet feetorclothesgive us “cold?”
A. Because the evaporationabsorbs heat from the body so abundantly, that it islowered below its natural standard; and therefore health is injured.
A. Because the evaporationabsorbs heat from the body so abundantly, that it islowered below its natural standard; and therefore health is injured.
Q.Why is itdangeroustosleepin adamp bed?A. Because theheat of the bodyis continually absorbedin converting the damp of the sheets into vapour; and as heat is abstracted from the body, its temperature is reducedbelow the healthy standard.
Q.Why is itdangeroustosleepin adamp bed?
Q.Why is itdangeroustosleepin adamp bed?
A. Because theheat of the bodyis continually absorbedin converting the damp of the sheets into vapour; and as heat is abstracted from the body, its temperature is reducedbelow the healthy standard.
A. Because theheat of the bodyis continually absorbedin converting the damp of the sheets into vapour; and as heat is abstracted from the body, its temperature is reducedbelow the healthy standard.
Q.Why do we not feel the same sensation of cold, if we throw amacintoshover ourwet clothes?A. The macintoshprevents evaporation, because the steam cannot escape through the air-tight fabric; and (as thewet cannot evaporatefrom the clothes) no heat is absorbed from our bodies.
Q.Why do we not feel the same sensation of cold, if we throw amacintoshover ourwet clothes?
Q.Why do we not feel the same sensation of cold, if we throw amacintoshover ourwet clothes?
A. The macintoshprevents evaporation, because the steam cannot escape through the air-tight fabric; and (as thewet cannot evaporatefrom the clothes) no heat is absorbed from our bodies.
A. The macintoshprevents evaporation, because the steam cannot escape through the air-tight fabric; and (as thewet cannot evaporatefrom the clothes) no heat is absorbed from our bodies.
Q.Why donot sailorsgetcold, who are so often wet all day withsea-water?A. Thesaltof the searetards evaporation; and (as the heat of the body is drawn offvery gradually) the sensation of cold is prevented.
Q.Why donot sailorsgetcold, who are so often wet all day withsea-water?
Q.Why donot sailorsgetcold, who are so often wet all day withsea-water?
A. Thesaltof the searetards evaporation; and (as the heat of the body is drawn offvery gradually) the sensation of cold is prevented.
A. Thesaltof the searetards evaporation; and (as the heat of the body is drawn offvery gradually) the sensation of cold is prevented.
Q.Why doessprinklingahot roomwith watercool it?A. The heat of the room causes arapid evaporation of the sprinkled water; and as the water evaporates,it absorbs heat from the room, and cools it.
Q.Why doessprinklingahot roomwith watercool it?
Q.Why doessprinklingahot roomwith watercool it?
A. The heat of the room causes arapid evaporation of the sprinkled water; and as the water evaporates,it absorbs heat from the room, and cools it.
A. The heat of the room causes arapid evaporation of the sprinkled water; and as the water evaporates,it absorbs heat from the room, and cools it.
Q.Why doeswateringthestreetsand roadscool them?A. The hot streets and roads part with their heatto promote the evaporation of the water sprinkled on them.
Q.Why doeswateringthestreetsand roadscool them?
Q.Why doeswateringthestreetsand roadscool them?
A. The hot streets and roads part with their heatto promote the evaporation of the water sprinkled on them.
A. The hot streets and roads part with their heatto promote the evaporation of the water sprinkled on them.
Q.Why does ashowerofrainseem tocooltheairin summer-time?A. The earth (being wet with the rain)parts with its heat to promote evaporation; and as theearthis cooled, itcools the airalso.
Q.Why does ashowerofrainseem tocooltheairin summer-time?
Q.Why does ashowerofrainseem tocooltheairin summer-time?
A. The earth (being wet with the rain)parts with its heat to promote evaporation; and as theearthis cooled, itcools the airalso.
A. The earth (being wet with the rain)parts with its heat to promote evaporation; and as theearthis cooled, itcools the airalso.
Q.Why islinen driedby being exposed to thewind?A. The air (blowing over the linen)promotes evaporation, by removing the vapour from thesurface of the wet linen, as soon as it is formed.
Q.Why islinen driedby being exposed to thewind?
Q.Why islinen driedby being exposed to thewind?
A. The air (blowing over the linen)promotes evaporation, by removing the vapour from thesurface of the wet linen, as soon as it is formed.
A. The air (blowing over the linen)promotes evaporation, by removing the vapour from thesurface of the wet linen, as soon as it is formed.
Q.Why islinen driedsooner in the openair, than in a confined room?A. Because the particles of vapour are more rapidly removed from the surface of the linen by evaporation.
Q.Why islinen driedsooner in the openair, than in a confined room?
Q.Why islinen driedsooner in the openair, than in a confined room?
A. Because the particles of vapour are more rapidly removed from the surface of the linen by evaporation.
A. Because the particles of vapour are more rapidly removed from the surface of the linen by evaporation.
Q.Why arewet summersgenerallysucceededbycold winters?A. Because the great evaporation (carried on through the wet summer)reduces the temperature of the earth lower than usual, and produces cold.
Q.Why arewet summersgenerallysucceededbycold winters?
Q.Why arewet summersgenerallysucceededbycold winters?
A. Because the great evaporation (carried on through the wet summer)reduces the temperature of the earth lower than usual, and produces cold.
A. Because the great evaporation (carried on through the wet summer)reduces the temperature of the earth lower than usual, and produces cold.
Q.Why isengland warmerthan it used to be, whenagueswere so common?A. Because it isbetter drainedandbetter cultivated.
Q.Why isengland warmerthan it used to be, whenagueswere so common?
Q.Why isengland warmerthan it used to be, whenagueswere so common?
A. Because it isbetter drainedandbetter cultivated.
A. Because it isbetter drainedandbetter cultivated.
Q.Why doesdrainingland promotewarmth?A. Because itdiminishes evaporation; in consequence of whichless heatis abstracted from the earth.
Q.Why doesdrainingland promotewarmth?
Q.Why doesdrainingland promotewarmth?
A. Because itdiminishes evaporation; in consequence of whichless heatis abstracted from the earth.
A. Because itdiminishes evaporation; in consequence of whichless heatis abstracted from the earth.
Q.Why doescultivationincrease thewarmthof a country?A. 1st—Becausehedges and belts of treesare multiplied;2ndly—Because the land isbetter drained;3rdly—Because the land isdug and ploughed;and4thly—Because the vastforests are cut down.
Q.Why doescultivationincrease thewarmthof a country?
Q.Why doescultivationincrease thewarmthof a country?
A. 1st—Becausehedges and belts of treesare multiplied;2ndly—Because the land isbetter drained;3rdly—Because the land isdug and ploughed;and4thly—Because the vastforests are cut down.
A. 1st—Becausehedges and belts of treesare multiplied;
2ndly—Because the land isbetter drained;
3rdly—Because the land isdug and ploughed;and
4thly—Because the vastforests are cut down.
Q.Why dohedgesandbeltsoftreespromotewarmth?A. Because theyretard evaporation, by keeping off thewind.
Q.Why dohedgesandbeltsoftreespromotewarmth?
Q.Why dohedgesandbeltsoftreespromotewarmth?
A. Because theyretard evaporation, by keeping off thewind.
A. Because theyretard evaporation, by keeping off thewind.
Q.If belts of trees promotewarmth, why doforestsproducecold?A. 1st—Because theydetain and condense the passing clouds:2ndly—They prevent the access of bothwind and sun:3rdly—The soil of forests is alwayscovered with long damp grass, rotting leaves, and thick brushwood: and4thly—There are always many hollows in every forestfull of stagnant water.
Q.If belts of trees promotewarmth, why doforestsproducecold?
Q.If belts of trees promotewarmth, why doforestsproducecold?
A. 1st—Because theydetain and condense the passing clouds:2ndly—They prevent the access of bothwind and sun:3rdly—The soil of forests is alwayscovered with long damp grass, rotting leaves, and thick brushwood: and4thly—There are always many hollows in every forestfull of stagnant water.
A. 1st—Because theydetain and condense the passing clouds:
2ndly—They prevent the access of bothwind and sun:
3rdly—The soil of forests is alwayscovered with long damp grass, rotting leaves, and thick brushwood: and
4thly—There are always many hollows in every forestfull of stagnant water.
Q.Why dolong grassandrotting leavespromotecold?A. Becausethey are always damp; and the evaporation which they promote,is constantly absorbing heatfrom the earth beneath.
Q.Why dolong grassandrotting leavespromotecold?
Q.Why dolong grassandrotting leavespromotecold?
A. Becausethey are always damp; and the evaporation which they promote,is constantly absorbing heatfrom the earth beneath.
A. Becausethey are always damp; and the evaporation which they promote,is constantly absorbing heatfrom the earth beneath.
Q.Why dodiggingandploughinghelp to make a countrywarm?A. Digging and ploughing helptopulverize the soil, by admittingair into it, and this increases its mean temperature.
Q.Why dodiggingandploughinghelp to make a countrywarm?
Q.Why dodiggingandploughinghelp to make a countrywarm?
A. Digging and ploughing helptopulverize the soil, by admittingair into it, and this increases its mean temperature.
A. Digging and ploughing helptopulverize the soil, by admittingair into it, and this increases its mean temperature.
Q.Why areFranceandGermanywarmernow, than when the vine would not ripen there?A. Chiefly becausetheir vast forests have been cut down; and the soil is betterdrained and cultivated.
Q.Why areFranceandGermanywarmernow, than when the vine would not ripen there?
Q.Why areFranceandGermanywarmernow, than when the vine would not ripen there?
A. Chiefly becausetheir vast forests have been cut down; and the soil is betterdrained and cultivated.
A. Chiefly becausetheir vast forests have been cut down; and the soil is betterdrained and cultivated.
Q.What becomes of thewaterofpondsandtubsin summer-time?A. Ponds and tubs in summer-time are often left dry, because their water isevaporated by the air.
Q.What becomes of thewaterofpondsandtubsin summer-time?
Q.What becomes of thewaterofpondsandtubsin summer-time?
A. Ponds and tubs in summer-time are often left dry, because their water isevaporated by the air.
A. Ponds and tubs in summer-time are often left dry, because their water isevaporated by the air.
Q.How is thisevaporation producedand carried on?A. The air contains heat, and changes thesurface of the water into vapour; this vapour (blending with the air)is soon wafted away; whilefreshportions of airblow over the water, and produce asimilar evaporation; till the pond or tub is left quite dry.
Q.How is thisevaporation producedand carried on?
Q.How is thisevaporation producedand carried on?
A. The air contains heat, and changes thesurface of the water into vapour; this vapour (blending with the air)is soon wafted away; whilefreshportions of airblow over the water, and produce asimilar evaporation; till the pond or tub is left quite dry.
A. The air contains heat, and changes thesurface of the water into vapour; this vapour (blending with the air)is soon wafted away; whilefreshportions of airblow over the water, and produce asimilar evaporation; till the pond or tub is left quite dry.
Q.Why are thewheelsof some machines keptconstantly wetwithwater?A.To carry off the heat(arising fromthe rapid motionof the wheels)by evaporation, as soon as it is developed.
Q.Why are thewheelsof some machines keptconstantly wetwithwater?
Q.Why are thewheelsof some machines keptconstantly wetwithwater?
A.To carry off the heat(arising fromthe rapid motionof the wheels)by evaporation, as soon as it is developed.
A.To carry off the heat(arising fromthe rapid motionof the wheels)by evaporation, as soon as it is developed.
Q.Why ismould hardenedby thesun?A. Because (when the moisture of the mould has beenevaporated by the sun) the earthy particlescome into closer contact, and the mass becomes more solid.
Q.Why ismould hardenedby thesun?
Q.Why ismould hardenedby thesun?
A. Because (when the moisture of the mould has beenevaporated by the sun) the earthy particlescome into closer contact, and the mass becomes more solid.
A. Because (when the moisture of the mould has beenevaporated by the sun) the earthy particlescome into closer contact, and the mass becomes more solid.
Q.Show thewisdomofgodin this arrangement.A. If the soil did not becomecrusty and hard in dry weather, theheat and drought would penetrate the soil, and kill both seeds and roots.
Q.Show thewisdomofgodin this arrangement.
Q.Show thewisdomofgodin this arrangement.
A. If the soil did not becomecrusty and hard in dry weather, theheat and drought would penetrate the soil, and kill both seeds and roots.
A. If the soil did not becomecrusty and hard in dry weather, theheat and drought would penetrate the soil, and kill both seeds and roots.
Q.Why isteacooledfasterin asaucerthan in a cup?A. Becauseevaporation is increasedbyincreasing the surface; and as tea in a saucerpresents a much larger surface to the air, its heat is more rapidly carried off by evaporation.(The subject of “convection” will be treated of in a future chapter, and would scarcely be understood in this place.)
Q.Why isteacooledfasterin asaucerthan in a cup?
Q.Why isteacooledfasterin asaucerthan in a cup?
A. Becauseevaporation is increasedbyincreasing the surface; and as tea in a saucerpresents a much larger surface to the air, its heat is more rapidly carried off by evaporation.(The subject of “convection” will be treated of in a future chapter, and would scarcely be understood in this place.)
A. Becauseevaporation is increasedbyincreasing the surface; and as tea in a saucerpresents a much larger surface to the air, its heat is more rapidly carried off by evaporation.
(The subject of “convection” will be treated of in a future chapter, and would scarcely be understood in this place.)
Q.Why is not thevapourof thesea salt?A. Because thesaltis alwaysleft behind, by the process of evaporation.
Q.Why is not thevapourof thesea salt?
Q.Why is not thevapourof thesea salt?
A. Because thesaltis alwaysleft behind, by the process of evaporation.
A. Because thesaltis alwaysleft behind, by the process of evaporation.
Q.Why does awhite crustappear (in hot weather) uponclotheswetted by sea water?A. The white crust is thesalt of the waterleft on the clothes by evaporation.
Q.Why does awhite crustappear (in hot weather) uponclotheswetted by sea water?
Q.Why does awhite crustappear (in hot weather) uponclotheswetted by sea water?
A. The white crust is thesalt of the waterleft on the clothes by evaporation.
A. The white crust is thesalt of the waterleft on the clothes by evaporation.
Q.Why does thiswhite crustalwaysdisappearinwetweather?A. Inwetweather themoisture of the air dissolves the salt; and, therefore, it no longer remains visible.
Q.Why does thiswhite crustalwaysdisappearinwetweather?
Q.Why does thiswhite crustalwaysdisappearinwetweather?
A. Inwetweather themoisture of the air dissolves the salt; and, therefore, it no longer remains visible.
A. Inwetweather themoisture of the air dissolves the salt; and, therefore, it no longer remains visible.
Q.Why shouldnotpersons, who take violent exercise,wearverythick clothing?A. When the heat of the body is increased by exercise,perspiration reduces the heat(by evaporation)to a healthy standard: as thick clothingprevents this evaporation, and confines the heat and perspirationto the body, it is injurious to health.
Q.Why shouldnotpersons, who take violent exercise,wearverythick clothing?
Q.Why shouldnotpersons, who take violent exercise,wearverythick clothing?
A. When the heat of the body is increased by exercise,perspiration reduces the heat(by evaporation)to a healthy standard: as thick clothingprevents this evaporation, and confines the heat and perspirationto the body, it is injurious to health.
A. When the heat of the body is increased by exercise,perspiration reduces the heat(by evaporation)to a healthy standard: as thick clothingprevents this evaporation, and confines the heat and perspirationto the body, it is injurious to health.
Q.How isheat communicatedfrom one body to another?A. 1. By Conduction. 2. By Absorption. 3. By Reflection. 4. By Radiation: and 5. By Convection.
Q.How isheat communicatedfrom one body to another?
Q.How isheat communicatedfrom one body to another?
A. 1. By Conduction. 2. By Absorption. 3. By Reflection. 4. By Radiation: and 5. By Convection.
A. 1. By Conduction. 2. By Absorption. 3. By Reflection. 4. By Radiation: and 5. By Convection.
Q.What is meant byconductionof heat?A. Heat communicated from one body to another,by actual contact.
Q.What is meant byconductionof heat?
Q.What is meant byconductionof heat?
A. Heat communicated from one body to another,by actual contact.
A. Heat communicated from one body to another,by actual contact.
Q.Why does apieceofwood(blazing atoneend)not feel hotat theotherend?A.Wood is a bad conductor of heat; and, therefore, heat does not traverse freely through it: hence, though one end of a stick be blazing-hot, the other end may be quite cold.
Q.Why does apieceofwood(blazing atoneend)not feel hotat theotherend?
Q.Why does apieceofwood(blazing atoneend)not feel hotat theotherend?
A.Wood is a bad conductor of heat; and, therefore, heat does not traverse freely through it: hence, though one end of a stick be blazing-hot, the other end may be quite cold.
A.Wood is a bad conductor of heat; and, therefore, heat does not traverse freely through it: hence, though one end of a stick be blazing-hot, the other end may be quite cold.
Q.Why dosome thingsfeel so muchcolderthan others?A. Principally becausethey are better conductors; and, therefore, draw off the heat from our body (which touches them) so much faster.
Q.Why dosome thingsfeel so muchcolderthan others?
Q.Why dosome thingsfeel so muchcolderthan others?
A. Principally becausethey are better conductors; and, therefore, draw off the heat from our body (which touches them) so much faster.
A. Principally becausethey are better conductors; and, therefore, draw off the heat from our body (which touches them) so much faster.
Q.What are thebest conductorsofheat?A.Dense solid bodies, such as metal and stone.
Q.What are thebest conductorsofheat?
Q.What are thebest conductorsofheat?
A.Dense solid bodies, such as metal and stone.
A.Dense solid bodies, such as metal and stone.
Q.Whichmetalsare the mostrapid conductorsofheat?A.Silveris the best conductor, thencopper, thengoldortin, theniron, thenzinc, and thenlead.
Q.Whichmetalsare the mostrapid conductorsofheat?
Q.Whichmetalsare the mostrapid conductorsofheat?
A.Silveris the best conductor, thencopper, thengoldortin, theniron, thenzinc, and thenlead.
A.Silveris the best conductor, thencopper, thengoldortin, theniron, thenzinc, and thenlead.
Q.What are theworst conductorsofheat?A. Alllight and porous bodies, such as hair, fur, wool, charcoal, and so on.
Q.What are theworst conductorsofheat?
Q.What are theworst conductorsofheat?
A. Alllight and porous bodies, such as hair, fur, wool, charcoal, and so on.
A. Alllight and porous bodies, such as hair, fur, wool, charcoal, and so on.
Q.Why arecooking vesselsso often furnished withwooden handles?A. Wood isnot a good conductor, like metal; and, therefore, many vessels (which are exposed to the heat of the fire)have wooden handles, lest they should burn our handswhen we take hold of them.
Q.Why arecooking vesselsso often furnished withwooden handles?
Q.Why arecooking vesselsso often furnished withwooden handles?
A. Wood isnot a good conductor, like metal; and, therefore, many vessels (which are exposed to the heat of the fire)have wooden handles, lest they should burn our handswhen we take hold of them.
A. Wood isnot a good conductor, like metal; and, therefore, many vessels (which are exposed to the heat of the fire)have wooden handles, lest they should burn our handswhen we take hold of them.
Q.Why is thehandleof ametal tea-potmade ofwood?A. Aswood is a bad conductor, the heat of the boiling water isnot so quickly conveyed to the wooden handle, nor so quicklypoured into the handby it, as when the handle is made of metal.
Q.Why is thehandleof ametal tea-potmade ofwood?
Q.Why is thehandleof ametal tea-potmade ofwood?
A. Aswood is a bad conductor, the heat of the boiling water isnot so quickly conveyed to the wooden handle, nor so quicklypoured into the handby it, as when the handle is made of metal.
A. Aswood is a bad conductor, the heat of the boiling water isnot so quickly conveyed to the wooden handle, nor so quicklypoured into the handby it, as when the handle is made of metal.
Q.Why would ametal handle burnthehandof the tea-maker?A. As metal is anexcellent conductor, the heat of the boiling waterrushes quickly into the metal handle, andinto the hand that touches it.
Q.Why would ametal handle burnthehandof the tea-maker?
Q.Why would ametal handle burnthehandof the tea-maker?
A. As metal is anexcellent conductor, the heat of the boiling waterrushes quickly into the metal handle, andinto the hand that touches it.
A. As metal is anexcellent conductor, the heat of the boiling waterrushes quickly into the metal handle, andinto the hand that touches it.
Q.How do you know that ametal handlewould behotterthan awoodenone?A. Bytouching the metal collarinto which the wooden handle is fixed: though thewooden handle is quite cold, thismetal collar is intensely hot.
Q.How do you know that ametal handlewould behotterthan awoodenone?
Q.How do you know that ametal handlewould behotterthan awoodenone?
A. Bytouching the metal collarinto which the wooden handle is fixed: though thewooden handle is quite cold, thismetal collar is intensely hot.
A. Bytouching the metal collarinto which the wooden handle is fixed: though thewooden handle is quite cold, thismetal collar is intensely hot.
Q.Why do persons use paper orwoollen kettle-holdersto take hold of a kettle with?A. Paper and woollen are both verybad conductors of heat; and, therefore, the heat of the kettle doesnot readily pass through them to the hand.
Q.Why do persons use paper orwoollen kettle-holdersto take hold of a kettle with?
Q.Why do persons use paper orwoollen kettle-holdersto take hold of a kettle with?
A. Paper and woollen are both verybad conductors of heat; and, therefore, the heat of the kettle doesnot readily pass through them to the hand.
A. Paper and woollen are both verybad conductors of heat; and, therefore, the heat of the kettle doesnot readily pass through them to the hand.
Q.Does the heat of the boiling kettleneverget through the woollen or paper kettle-holder?A. Yes; but though the kettle-holder became as hot as the kettle itself, it would neverfeelso hot.
Q.Does the heat of the boiling kettleneverget through the woollen or paper kettle-holder?
Q.Does the heat of the boiling kettleneverget through the woollen or paper kettle-holder?
A. Yes; but though the kettle-holder became as hot as the kettle itself, it would neverfeelso hot.
A. Yes; but though the kettle-holder became as hot as the kettle itself, it would neverfeelso hot.
Q.Why would not the kettle-holderfeelso hot as the kettle, when it really is of the same temperature?A. Because (being a verybadconductor)it disposes of its heat so slowly, that it isscarcely perceptible; but metal (being anexcellentconductor) disposes of its heat soquickly, that the sudden influx is painful.
Q.Why would not the kettle-holderfeelso hot as the kettle, when it really is of the same temperature?
Q.Why would not the kettle-holderfeelso hot as the kettle, when it really is of the same temperature?
A. Because (being a verybadconductor)it disposes of its heat so slowly, that it isscarcely perceptible; but metal (being anexcellentconductor) disposes of its heat soquickly, that the sudden influx is painful.
A. Because (being a verybadconductor)it disposes of its heat so slowly, that it isscarcely perceptible; but metal (being anexcellentconductor) disposes of its heat soquickly, that the sudden influx is painful.
Q.Why then doeshot metalfeel so muchmoreintenselywarmthanhot wool?A. Because it gives out a muchgreater quantity of heat in the same space of time; and theinfluxof heat is, therefore,more perceptible.
Q.Why then doeshot metalfeel so muchmoreintenselywarmthanhot wool?
Q.Why then doeshot metalfeel so muchmoreintenselywarmthanhot wool?
A. Because it gives out a muchgreater quantity of heat in the same space of time; and theinfluxof heat is, therefore,more perceptible.
A. Because it gives out a muchgreater quantity of heat in the same space of time; and theinfluxof heat is, therefore,more perceptible.
Q.Why doesmoneyin our pocket feel sohot, when we standbeforeafire?A. Metal is anexcellent conductor; and, therefore, becomes rapidly heated. For the same reason it becomesrapidly cold, when it comes in contact with a bodycolder than itself.
Q.Why doesmoneyin our pocket feel sohot, when we standbeforeafire?
Q.Why doesmoneyin our pocket feel sohot, when we standbeforeafire?
A. Metal is anexcellent conductor; and, therefore, becomes rapidly heated. For the same reason it becomesrapidly cold, when it comes in contact with a bodycolder than itself.
A. Metal is anexcellent conductor; and, therefore, becomes rapidly heated. For the same reason it becomesrapidly cold, when it comes in contact with a bodycolder than itself.
Q.Why does apump-handlefeel intenselycoldinwinter?A. As metal is anexcellent conductor, when the hot hand touches the cold pump-handle, the heat passes rapidlyfrom the hand into the iron; and this rapid loss of heat produces a sensation of intense coldness.
Q.Why does apump-handlefeel intenselycoldinwinter?
Q.Why does apump-handlefeel intenselycoldinwinter?
A. As metal is anexcellent conductor, when the hot hand touches the cold pump-handle, the heat passes rapidlyfrom the hand into the iron; and this rapid loss of heat produces a sensation of intense coldness.
A. As metal is anexcellent conductor, when the hot hand touches the cold pump-handle, the heat passes rapidlyfrom the hand into the iron; and this rapid loss of heat produces a sensation of intense coldness.
Q.Is the ironhandleof the pump reallycolderthan the woodenpumpitself?A. No; every inanimate substance (exposed to the same temperature) possesses thesame degree of heat.
Q.Is the ironhandleof the pump reallycolderthan the woodenpumpitself?
Q.Is the ironhandleof the pump reallycolderthan the woodenpumpitself?
A. No; every inanimate substance (exposed to the same temperature) possesses thesame degree of heat.
A. No; every inanimate substance (exposed to the same temperature) possesses thesame degree of heat.
Q.Why then does theiron handleseem somuch colderthan thewooden pump?A. Merely because theiron is a better conductor; and, therefore,draws off the heat from our handmuch more rapidly than wood does.
Q.Why then does theiron handleseem somuch colderthan thewooden pump?
Q.Why then does theiron handleseem somuch colderthan thewooden pump?
A. Merely because theiron is a better conductor; and, therefore,draws off the heat from our handmuch more rapidly than wood does.
A. Merely because theiron is a better conductor; and, therefore,draws off the heat from our handmuch more rapidly than wood does.
Q.Why does astoneor marblehearthfeel to the feet so muchcolderthan acarpetor hearth-rug?A. Becausestone and marble are good conductors, butwoollen carpets and hearth-rugsare verybad conductors.
Q.Why does astoneor marblehearthfeel to the feet so muchcolderthan acarpetor hearth-rug?
Q.Why does astoneor marblehearthfeel to the feet so muchcolderthan acarpetor hearth-rug?
A. Becausestone and marble are good conductors, butwoollen carpets and hearth-rugsare verybad conductors.
A. Becausestone and marble are good conductors, butwoollen carpets and hearth-rugsare verybad conductors.
Q.Why does thestone hearthmake ourfeet cold?A. As soon as the hearth-stone has absorbed a portion of heat from our foot, it instantly disposes of it, andcalls for a fresh supply; till the hearth-stone has become of thesame temperature as the foot placed upon it.
Q.Why does thestone hearthmake ourfeet cold?
Q.Why does thestone hearthmake ourfeet cold?
A. As soon as the hearth-stone has absorbed a portion of heat from our foot, it instantly disposes of it, andcalls for a fresh supply; till the hearth-stone has become of thesame temperature as the foot placed upon it.
A. As soon as the hearth-stone has absorbed a portion of heat from our foot, it instantly disposes of it, andcalls for a fresh supply; till the hearth-stone has become of thesame temperature as the foot placed upon it.
Q.Do not the woollencarpetandhearth-rug, also, conduct heat from the human body?A. Yes; (but being verybad conductors) they conveythe heat away so slowly, that it is scarcely perceptible.
Q.Do not the woollencarpetandhearth-rug, also, conduct heat from the human body?
Q.Do not the woollencarpetandhearth-rug, also, conduct heat from the human body?
A. Yes; (but being verybad conductors) they conveythe heat away so slowly, that it is scarcely perceptible.
A. Yes; (but being verybad conductors) they conveythe heat away so slowly, that it is scarcely perceptible.
Q.Is thecold hearth-stoneandwarm carpetthen of thesame temperature?A. Yes; everything in the room isreally of the same temperature; but some feel colder than othersbecause they are better conductors.
Q.Is thecold hearth-stoneandwarm carpetthen of thesame temperature?
Q.Is thecold hearth-stoneandwarm carpetthen of thesame temperature?
A. Yes; everything in the room isreally of the same temperature; but some feel colder than othersbecause they are better conductors.
A. Yes; everything in the room isreally of the same temperature; but some feel colder than othersbecause they are better conductors.
Q.Howlongwill the hearth-stone feel cold to the feet resting on it?A. Till thefeet and the hearth-stone are both of the same temperature; and then the sensation of cold in the hearth-stone will go off.
Q.Howlongwill the hearth-stone feel cold to the feet resting on it?
Q.Howlongwill the hearth-stone feel cold to the feet resting on it?
A. Till thefeet and the hearth-stone are both of the same temperature; and then the sensation of cold in the hearth-stone will go off.
A. Till thefeet and the hearth-stone are both of the same temperature; and then the sensation of cold in the hearth-stone will go off.
Q.Why would not thehearth-stonefeelcold, when it is of thesametemperature as ourfeet?A. Because the heat would no longerrush out of our feet into the hearth-stone, in order to produce an equilibrium.
Q.Why would not thehearth-stonefeelcold, when it is of thesametemperature as ourfeet?
Q.Why would not thehearth-stonefeelcold, when it is of thesametemperature as ourfeet?
A. Because the heat would no longerrush out of our feet into the hearth-stone, in order to produce an equilibrium.
A. Because the heat would no longerrush out of our feet into the hearth-stone, in order to produce an equilibrium.
Q.Why does thehearth-stone(when the fire is lighted) feel so muchhotterthan thehearth-rug?A. The hearth-stone is anexcellent conductor; and, therefore,parts with its heat more readilythan the woollen hearth-rug; which (being a verybad conductor) parts with its heat reluctantly.
Q.Why does thehearth-stone(when the fire is lighted) feel so muchhotterthan thehearth-rug?
Q.Why does thehearth-stone(when the fire is lighted) feel so muchhotterthan thehearth-rug?
A. The hearth-stone is anexcellent conductor; and, therefore,parts with its heat more readilythan the woollen hearth-rug; which (being a verybad conductor) parts with its heat reluctantly.
A. The hearth-stone is anexcellent conductor; and, therefore,parts with its heat more readilythan the woollen hearth-rug; which (being a verybad conductor) parts with its heat reluctantly.
Q.Why doespartingwithheat rapidlymake thehearth-stonefeelwarm?A. As the heat of the stone rushesquickly into our foot, it raises its temperatureso suddenly, that we cannothelp perceiving the increase of heat.
Q.Why doespartingwithheat rapidlymake thehearth-stonefeelwarm?
Q.Why doespartingwithheat rapidlymake thehearth-stonefeelwarm?
A. As the heat of the stone rushesquickly into our foot, it raises its temperatureso suddenly, that we cannothelp perceiving the increase of heat.
A. As the heat of the stone rushesquickly into our foot, it raises its temperatureso suddenly, that we cannothelp perceiving the increase of heat.
Q.Why does the non-conducting power of thehearth-rugprevent its feeling sohotas it really is?A. Because it parts with its heatso slowly and gradually, that we scarcelyperceive its transmissioninto our feet.
Q.Why does the non-conducting power of thehearth-rugprevent its feeling sohotas it really is?
Q.Why does the non-conducting power of thehearth-rugprevent its feeling sohotas it really is?
A. Because it parts with its heatso slowly and gradually, that we scarcelyperceive its transmissioninto our feet.
A. Because it parts with its heatso slowly and gradually, that we scarcelyperceive its transmissioninto our feet.
Q.When we plunge ourhandsinto a basin ofwater, why does it produce a sensation ofcold?A. Though the water (in which we wash)is really warmerthan the air of our bed-room; yet because it is abetter conductor, itfeels colder.
Q.When we plunge ourhandsinto a basin ofwater, why does it produce a sensation ofcold?
Q.When we plunge ourhandsinto a basin ofwater, why does it produce a sensation ofcold?
A. Though the water (in which we wash)is really warmerthan the air of our bed-room; yet because it is abetter conductor, itfeels colder.
A. Though the water (in which we wash)is really warmerthan the air of our bed-room; yet because it is abetter conductor, itfeels colder.
Q.Why does theconductingpower of water make it feelcolderthan the air, though in reality it iswarmer?A. Becauseit abstracts heat from our hands so rapidly, that we feel its loss; but the air abstracts heatso very slowly, that itsgradual loss is hardly perceptible.
Q.Why does theconductingpower of water make it feelcolderthan the air, though in reality it iswarmer?
Q.Why does theconductingpower of water make it feelcolderthan the air, though in reality it iswarmer?
A. Becauseit abstracts heat from our hands so rapidly, that we feel its loss; but the air abstracts heatso very slowly, that itsgradual loss is hardly perceptible.
A. Becauseit abstracts heat from our hands so rapidly, that we feel its loss; but the air abstracts heatso very slowly, that itsgradual loss is hardly perceptible.
Q.Is water agood conductorof heat?A. No;no liquid is a good conductorof heat; but yet water is amuch better conductor than air.
Q.Is water agood conductorof heat?
Q.Is water agood conductorof heat?
A. No;no liquid is a good conductorof heat; but yet water is amuch better conductor than air.
A. No;no liquid is a good conductorof heat; but yet water is amuch better conductor than air.
Q.Why iswaterabetter conductorof heat thanair?A. Becauseit is less subtile; and the conducting power of any substance depends uponits solidity, or thecloseness of its particles.
Q.Why iswaterabetter conductorof heat thanair?
Q.Why iswaterabetter conductorof heat thanair?
A. Becauseit is less subtile; and the conducting power of any substance depends uponits solidity, or thecloseness of its particles.
A. Becauseit is less subtile; and the conducting power of any substance depends uponits solidity, or thecloseness of its particles.
Q.How do you know thatwaterisnotagood conductorof heat?A. Because water may be made toboil at its surface, without imparting sufficient heat tomelt ice a quarter of an inch below the boiling surface.
Q.How do you know thatwaterisnotagood conductorof heat?
Q.How do you know thatwaterisnotagood conductorof heat?
A. Because water may be made toboil at its surface, without imparting sufficient heat tomelt ice a quarter of an inch below the boiling surface.
A. Because water may be made toboil at its surface, without imparting sufficient heat tomelt ice a quarter of an inch below the boiling surface.
Q.Why arenot liquids good conductorsof heat?A. Because the heat (which should be transmitted)produces evaporation, andflies off in the vapour.
Q.Why arenot liquids good conductorsof heat?
Q.Why arenot liquids good conductorsof heat?
A. Because the heat (which should be transmitted)produces evaporation, andflies off in the vapour.
A. Because the heat (which should be transmitted)produces evaporation, andflies off in the vapour.
Q.Why does apoker(resting on the fender) feel so muchcolderthan thehearth-rug, which is further off the fire?A. The poker (being an excellent conductor)draws heat from the hand much more quickly than the rug, which is a bad conductor: and, therefore, (though both areequally warm) the poker seems to be much colder.
Q.Why does apoker(resting on the fender) feel so muchcolderthan thehearth-rug, which is further off the fire?
Q.Why does apoker(resting on the fender) feel so muchcolderthan thehearth-rug, which is further off the fire?
A. The poker (being an excellent conductor)draws heat from the hand much more quickly than the rug, which is a bad conductor: and, therefore, (though both areequally warm) the poker seems to be much colder.
A. The poker (being an excellent conductor)draws heat from the hand much more quickly than the rug, which is a bad conductor: and, therefore, (though both areequally warm) the poker seems to be much colder.
Q.Why arehot bricks(wrapped in cloth) employed in cold weather tokeepthefeet warm?A. Bricks arebad conductorsof heat, and cloth or flannelstill worse: therefore a hot brick (wrapped in flannel) willretain its heat a very long time.
Q.Why arehot bricks(wrapped in cloth) employed in cold weather tokeepthefeet warm?
Q.Why arehot bricks(wrapped in cloth) employed in cold weather tokeepthefeet warm?
A. Bricks arebad conductorsof heat, and cloth or flannelstill worse: therefore a hot brick (wrapped in flannel) willretain its heat a very long time.
A. Bricks arebad conductorsof heat, and cloth or flannelstill worse: therefore a hot brick (wrapped in flannel) willretain its heat a very long time.
Q.Why is atin pan(filled withhot water) employed as afoot warmer?A. Becausepolished tin(being a bad radiator of heat)keeps hot a very long time; and warms the feet resting upon it.
Q.Why is atin pan(filled withhot water) employed as afoot warmer?
Q.Why is atin pan(filled withhot water) employed as afoot warmer?
A. Becausepolished tin(being a bad radiator of heat)keeps hot a very long time; and warms the feet resting upon it.
A. Becausepolished tin(being a bad radiator of heat)keeps hot a very long time; and warms the feet resting upon it.
Q.What is meant by being a “badradiatorof heat?”A. To radiate heat is tothrow off heat by rays, as the sun; a polished tin pan doesnot throw off the heat of boiling waterfrom its surface, butkeeps it in.
Q.What is meant by being a “badradiatorof heat?”
Q.What is meant by being a “badradiatorof heat?”
A. To radiate heat is tothrow off heat by rays, as the sun; a polished tin pan doesnot throw off the heat of boiling waterfrom its surface, butkeeps it in.
A. To radiate heat is tothrow off heat by rays, as the sun; a polished tin pan doesnot throw off the heat of boiling waterfrom its surface, butkeeps it in.
Q.Why is thetin foot-warmercovered withflannel?A. 1st—To prevent the perspiration of the foot from taking off thepolishof the tin:2ndly—Flannel is avery bad conductor; and, therefore, helps to keep the tin hotlonger: and3rdly—If the feet werenot protected, the conducting surface of the tinwould feel painfully hot.
Q.Why is thetin foot-warmercovered withflannel?
Q.Why is thetin foot-warmercovered withflannel?
A. 1st—To prevent the perspiration of the foot from taking off thepolishof the tin:2ndly—Flannel is avery bad conductor; and, therefore, helps to keep the tin hotlonger: and3rdly—If the feet werenot protected, the conducting surface of the tinwould feel painfully hot.
A. 1st—To prevent the perspiration of the foot from taking off thepolishof the tin:
2ndly—Flannel is avery bad conductor; and, therefore, helps to keep the tin hotlonger: and
3rdly—If the feet werenot protected, the conducting surface of the tinwould feel painfully hot.
Q.What harm would it be if thepolishof the tin were injured by the perspiration of our feet?A.Polishedtin throws off its heatvery slowly; but dull, scratched, painted, or dirty tin,throws off its heat very quickly: if, therefore, the tin foot-warmer were tolose its polish, it wouldget cold in a much shorter time.
Q.What harm would it be if thepolishof the tin were injured by the perspiration of our feet?
Q.What harm would it be if thepolishof the tin were injured by the perspiration of our feet?
A.Polishedtin throws off its heatvery slowly; but dull, scratched, painted, or dirty tin,throws off its heat very quickly: if, therefore, the tin foot-warmer were tolose its polish, it wouldget cold in a much shorter time.
A.Polishedtin throws off its heatvery slowly; but dull, scratched, painted, or dirty tin,throws off its heat very quickly: if, therefore, the tin foot-warmer were tolose its polish, it wouldget cold in a much shorter time.
Q.Why arefurnacesand stoves (where muchheatis required) built of porousbrick?A. As bricks are bad conductors, theyprevent the escape of heat: and are, therefore, employed where great heat is required.
Q.Why arefurnacesand stoves (where muchheatis required) built of porousbrick?
Q.Why arefurnacesand stoves (where muchheatis required) built of porousbrick?
A. As bricks are bad conductors, theyprevent the escape of heat: and are, therefore, employed where great heat is required.
A. As bricks are bad conductors, theyprevent the escape of heat: and are, therefore, employed where great heat is required.
Q.Why arefurnace doors, &c. frequentlycoveredwith a paste ofclayandsand?A. Because this paste is avery bad conductor of heat; and, therefore, prevents theescape of heat from the furnace.
Q.Why arefurnace doors, &c. frequentlycoveredwith a paste ofclayandsand?
Q.Why arefurnace doors, &c. frequentlycoveredwith a paste ofclayandsand?
A. Because this paste is avery bad conductor of heat; and, therefore, prevents theescape of heat from the furnace.
A. Because this paste is avery bad conductor of heat; and, therefore, prevents theescape of heat from the furnace.
Q.If a stove be placed in themiddleof a room, should it be made of bricks oriron?A. A stove in themiddle of a roomshould be made ofiron; because ironis anexcellent conductor, and rapidly communicates its heat to the air around.
Q.If a stove be placed in themiddleof a room, should it be made of bricks oriron?
Q.If a stove be placed in themiddleof a room, should it be made of bricks oriron?
A. A stove in themiddle of a roomshould be made ofiron; because ironis anexcellent conductor, and rapidly communicates its heat to the air around.
A. A stove in themiddle of a roomshould be made ofiron; because ironis anexcellent conductor, and rapidly communicates its heat to the air around.
Q.Why does the Bible say, that God “givethsnowlikewool?”A. Assnow is a very bad conductor of heat, it protects vegetables and seeds from the frost and cold.
Q.Why does the Bible say, that God “givethsnowlikewool?”
Q.Why does the Bible say, that God “givethsnowlikewool?”
A. Assnow is a very bad conductor of heat, it protects vegetables and seeds from the frost and cold.
A. Assnow is a very bad conductor of heat, it protects vegetables and seeds from the frost and cold.
Q.How does the non-conducting power ofsnow protect vegetablesfrom thefrostand cold?A. As snow is a bad conductor, it prevents theheatof the earthfrom being drawn offby the cold air which rests upon it.
Q.How does the non-conducting power ofsnow protect vegetablesfrom thefrostand cold?
Q.How does the non-conducting power ofsnow protect vegetablesfrom thefrostand cold?
A. As snow is a bad conductor, it prevents theheatof the earthfrom being drawn offby the cold air which rests upon it.
A. As snow is a bad conductor, it prevents theheatof the earthfrom being drawn offby the cold air which rests upon it.