Q.Why is thelidof akettleso intenselyhot, when the water boils?A. The bright metal lid of the kettleis an admirable conductorof heat; and, therefore,the heat from the boiling water pours into our handthe moment we touch it.
Q.Why is thelidof akettleso intenselyhot, when the water boils?
Q.Why is thelidof akettleso intenselyhot, when the water boils?
A. The bright metal lid of the kettleis an admirable conductorof heat; and, therefore,the heat from the boiling water pours into our handthe moment we touch it.
A. The bright metal lid of the kettleis an admirable conductorof heat; and, therefore,the heat from the boiling water pours into our handthe moment we touch it.
Q.Show the benefit ofsmokeincooking.A. The carbon of the fuel (which flies off in smoke) naturallyblackensall culinary vessels set upon the fire to boil, and thus renders them fit for use.(“Culinary vessels” are vessels used in kitchens for cooking, as saucepans, boilers, kettles, &c.)
Q.Show the benefit ofsmokeincooking.
Q.Show the benefit ofsmokeincooking.
A. The carbon of the fuel (which flies off in smoke) naturallyblackensall culinary vessels set upon the fire to boil, and thus renders them fit for use.(“Culinary vessels” are vessels used in kitchens for cooking, as saucepans, boilers, kettles, &c.)
A. The carbon of the fuel (which flies off in smoke) naturallyblackensall culinary vessels set upon the fire to boil, and thus renders them fit for use.
(“Culinary vessels” are vessels used in kitchens for cooking, as saucepans, boilers, kettles, &c.)
Q.How doessmokemake culinary vesselsfitforuse?A. If it were not for thesmoke, (which gathers round a kettle or saucepan)heat would not be absorbed, and the process of boiling would be greatly retarded.
Q.How doessmokemake culinary vesselsfitforuse?
Q.How doessmokemake culinary vesselsfitforuse?
A. If it were not for thesmoke, (which gathers round a kettle or saucepan)heat would not be absorbed, and the process of boiling would be greatly retarded.
A. If it were not for thesmoke, (which gathers round a kettle or saucepan)heat would not be absorbed, and the process of boiling would be greatly retarded.
Q.Why is boiling waterkept hotbest in abright metalpot?A. Because bright metal being abad radiatorwill notthrow off the heatof the boiling waterfrom its surface.
Q.Why is boiling waterkept hotbest in abright metalpot?
Q.Why is boiling waterkept hotbest in abright metalpot?
A. Because bright metal being abad radiatorwill notthrow off the heatof the boiling waterfrom its surface.
A. Because bright metal being abad radiatorwill notthrow off the heatof the boiling waterfrom its surface.
Q.Why iswater kept coldin summer-time in abright metalpot, better than in anearthenvessel?A. Because bright metalwill not absorb heatfrom the hot air, like anearthen vessel; in consequence of which, the water is kept cooler.
Q.Why iswater kept coldin summer-time in abright metalpot, better than in anearthenvessel?
Q.Why iswater kept coldin summer-time in abright metalpot, better than in anearthenvessel?
A. Because bright metalwill not absorb heatfrom the hot air, like anearthen vessel; in consequence of which, the water is kept cooler.
A. Because bright metalwill not absorb heatfrom the hot air, like anearthen vessel; in consequence of which, the water is kept cooler.
Q.Why aredinner-coversmade ofbright tinorsilver?A. Light-coloured and highly-polished metalis a very bad radiator of heat; and, therefore, bright tin or silver will not allow the heat of the cooked foodto escape through the cover by radiation.
Q.Why aredinner-coversmade ofbright tinorsilver?
Q.Why aredinner-coversmade ofbright tinorsilver?
A. Light-coloured and highly-polished metalis a very bad radiator of heat; and, therefore, bright tin or silver will not allow the heat of the cooked foodto escape through the cover by radiation.
A. Light-coloured and highly-polished metalis a very bad radiator of heat; and, therefore, bright tin or silver will not allow the heat of the cooked foodto escape through the cover by radiation.
Q.Why should ameat-coverbe very brightlypolished?A. If the cover bedull or scratchedit willabsorb heat from the hot food beneath it; and (instead ofkeeping it hot) willmake it cold.
Q.Why should ameat-coverbe very brightlypolished?
Q.Why should ameat-coverbe very brightlypolished?
A. If the cover bedull or scratchedit willabsorb heat from the hot food beneath it; and (instead ofkeeping it hot) willmake it cold.
A. If the cover bedull or scratchedit willabsorb heat from the hot food beneath it; and (instead ofkeeping it hot) willmake it cold.
Q.Why should asilver meat-coverbeplain, and notchased?A. If the cover bechased, it willabsorb the heat of the foodcovered by it; and instead ofkeeping it hot, willmake it cold by absorption.
Q.Why should asilver meat-coverbeplain, and notchased?
Q.Why should asilver meat-coverbeplain, and notchased?
A. If the cover bechased, it willabsorb the heat of the foodcovered by it; and instead ofkeeping it hot, willmake it cold by absorption.
A. If the cover bechased, it willabsorb the heat of the foodcovered by it; and instead ofkeeping it hot, willmake it cold by absorption.
Q.What isdew?A. Dew is thevapour of the air condensed, by coming in contact with bodiescolder than itself.
Q.What isdew?
Q.What isdew?
A. Dew is thevapour of the air condensed, by coming in contact with bodiescolder than itself.
A. Dew is thevapour of the air condensed, by coming in contact with bodiescolder than itself.
Q.Why is thegroundsometimescoveredwithdew?A. Theearth is more heatedby solar raysthan the air, during theday; but atnight, the earthparts with more heatthan theair, and becomes (in consequence) 5 or 10 degreescolder.
Q.Why is thegroundsometimescoveredwithdew?
Q.Why is thegroundsometimescoveredwithdew?
A. Theearth is more heatedby solar raysthan the air, during theday; but atnight, the earthparts with more heatthan theair, and becomes (in consequence) 5 or 10 degreescolder.
A. Theearth is more heatedby solar raysthan the air, during theday; but atnight, the earthparts with more heatthan theair, and becomes (in consequence) 5 or 10 degreescolder.
Q.How does theearthbeingcolderthan theairaccount for the deposition ofdew?A. As soon as the airtouches the cold earth, its warm vapour ischilled, andcondensed into dew.
Q.How does theearthbeingcolderthan theairaccount for the deposition ofdew?
Q.How does theearthbeingcolderthan theairaccount for the deposition ofdew?
A. As soon as the airtouches the cold earth, its warm vapour ischilled, andcondensed into dew.
A. As soon as the airtouches the cold earth, its warm vapour ischilled, andcondensed into dew.
Q.Why is the surface of theground colderin afineclearnight, than in acloudyone?A. On a fine clear star-light night,heat radiates from the earth freely, and is lost in open space: but on acloudynight, the cloudsarrest the process of radiation.
Q.Why is the surface of theground colderin afineclearnight, than in acloudyone?
Q.Why is the surface of theground colderin afineclearnight, than in acloudyone?
A. On a fine clear star-light night,heat radiates from the earth freely, and is lost in open space: but on acloudynight, the cloudsarrest the process of radiation.
A. On a fine clear star-light night,heat radiates from the earth freely, and is lost in open space: but on acloudynight, the cloudsarrest the process of radiation.
Q.Why isdewdeposited only on afineclearnight?A. Because, when the night isclearandfine, thesurface of the ground radiates heat most freely; and (being cooled down by this loss of heat)chills the vapour of the air into dew.
Q.Why isdewdeposited only on afineclearnight?
Q.Why isdewdeposited only on afineclearnight?
A. Because, when the night isclearandfine, thesurface of the ground radiates heat most freely; and (being cooled down by this loss of heat)chills the vapour of the air into dew.
A. Because, when the night isclearandfine, thesurface of the ground radiates heat most freely; and (being cooled down by this loss of heat)chills the vapour of the air into dew.
Q.Why is thereno dewon a dullcloudy night?A. The cloudsarrest the radiation of heat from the earth; and (as the heat cannot freely escape) the surface is not sufficiently cooled downto chill the vapour of the air into dew.
Q.Why is thereno dewon a dullcloudy night?
Q.Why is thereno dewon a dullcloudy night?
A. The cloudsarrest the radiation of heat from the earth; and (as the heat cannot freely escape) the surface is not sufficiently cooled downto chill the vapour of the air into dew.
A. The cloudsarrest the radiation of heat from the earth; and (as the heat cannot freely escape) the surface is not sufficiently cooled downto chill the vapour of the air into dew.
Q.Why is acloudy night warmerthan afineone?A. Because the cloudsprevent the radiation of heat from the earth; and, therefore, the surface of the earth remainswarmeron a dull cloudy night.
Q.Why is acloudy night warmerthan afineone?
Q.Why is acloudy night warmerthan afineone?
A. Because the cloudsprevent the radiation of heat from the earth; and, therefore, the surface of the earth remainswarmeron a dull cloudy night.
A. Because the cloudsprevent the radiation of heat from the earth; and, therefore, the surface of the earth remainswarmeron a dull cloudy night.
Q.Why isdewmostabundantin situations mostexposed?A. Because the radiation of heatis not arrestedby houses, trees, hedges, or any other thing.
Q.Why isdewmostabundantin situations mostexposed?
Q.Why isdewmostabundantin situations mostexposed?
A. Because the radiation of heatis not arrestedby houses, trees, hedges, or any other thing.
A. Because the radiation of heatis not arrestedby houses, trees, hedges, or any other thing.
Q.Why is there scarcely anydewunder a shadytree?A. The shady head of the tree botharrests the radiation of heat from the earth, and also radiates some of its own heattowards the earth; and, therefore, the ground (underneath a tree)is not sufficiently cooleddown to chill the vapour of the air into dew.
Q.Why is there scarcely anydewunder a shadytree?
Q.Why is there scarcely anydewunder a shadytree?
A. The shady head of the tree botharrests the radiation of heat from the earth, and also radiates some of its own heattowards the earth; and, therefore, the ground (underneath a tree)is not sufficiently cooleddown to chill the vapour of the air into dew.
A. The shady head of the tree botharrests the radiation of heat from the earth, and also radiates some of its own heattowards the earth; and, therefore, the ground (underneath a tree)is not sufficiently cooleddown to chill the vapour of the air into dew.
Q.Why is there never muchdewat the foot ofwallsandhedges?A. 1st—Because the wall or hedge acts as a screen,to arrest the radiation of heat from the earth: and2ndly—The wall or hedge alsoradiates some portion of heattowards the earth.
Q.Why is there never muchdewat the foot ofwallsandhedges?
Q.Why is there never muchdewat the foot ofwallsandhedges?
A. 1st—Because the wall or hedge acts as a screen,to arrest the radiation of heat from the earth: and2ndly—The wall or hedge alsoradiates some portion of heattowards the earth.
A. 1st—Because the wall or hedge acts as a screen,to arrest the radiation of heat from the earth: and
2ndly—The wall or hedge alsoradiates some portion of heattowards the earth.
Q.How do these things prevent the deposition of dew?A. As the ground (beneath a wall, tree, or hedge) isnot cooled by the radiation of heat, it remains of thesame temperature as the airabove it; in consequence of which, the vapours of the air arenot chilled by it into dew.
Q.How do these things prevent the deposition of dew?
Q.How do these things prevent the deposition of dew?
A. As the ground (beneath a wall, tree, or hedge) isnot cooled by the radiation of heat, it remains of thesame temperature as the airabove it; in consequence of which, the vapours of the air arenot chilled by it into dew.
A. As the ground (beneath a wall, tree, or hedge) isnot cooled by the radiation of heat, it remains of thesame temperature as the airabove it; in consequence of which, the vapours of the air arenot chilled by it into dew.
Q.Why is there little orno dewbeneath aflower-awning, although that awning be open on all four sides?A. 1st—Because the awningarrests the radiation of heat from the ground beneath: and2ndly—Itradiates some of its own heat downwards; in consequence of which, the ground beneath an awning isnot sufficiently cooled downto chill the vapour of air into dew.
Q.Why is there little orno dewbeneath aflower-awning, although that awning be open on all four sides?
Q.Why is there little orno dewbeneath aflower-awning, although that awning be open on all four sides?
A. 1st—Because the awningarrests the radiation of heat from the ground beneath: and2ndly—Itradiates some of its own heat downwards; in consequence of which, the ground beneath an awning isnot sufficiently cooled downto chill the vapour of air into dew.
A. 1st—Because the awningarrests the radiation of heat from the ground beneath: and
2ndly—Itradiates some of its own heat downwards; in consequence of which, the ground beneath an awning isnot sufficiently cooled downto chill the vapour of air into dew.
Q.How can a thin covering ofbassor evenmuslinprotect trees fromfrost?A. Becauseany coveringprevents theradiation of heat from the tree; and if the tree benot cooled down by radiation, the vapour of the air willnot be frozenas it comes in contact with it.
Q.How can a thin covering ofbassor evenmuslinprotect trees fromfrost?
Q.How can a thin covering ofbassor evenmuslinprotect trees fromfrost?
A. Becauseany coveringprevents theradiation of heat from the tree; and if the tree benot cooled down by radiation, the vapour of the air willnot be frozenas it comes in contact with it.
A. Becauseany coveringprevents theradiation of heat from the tree; and if the tree benot cooled down by radiation, the vapour of the air willnot be frozenas it comes in contact with it.
Q.Why is thebassorcanvassitself (which covers the tree) alwaysdrenchedwithdew?A. The bass or canvass coveringradiates heatbothupwards and downwards; and is, therefore,so cooled down, that it readilychills all the vapour of the air(which passes over it)into dew.
Q.Why is thebassorcanvassitself (which covers the tree) alwaysdrenchedwithdew?
Q.Why is thebassorcanvassitself (which covers the tree) alwaysdrenchedwithdew?
A. The bass or canvass coveringradiates heatbothupwards and downwards; and is, therefore,so cooled down, that it readilychills all the vapour of the air(which passes over it)into dew.
A. The bass or canvass coveringradiates heatbothupwards and downwards; and is, therefore,so cooled down, that it readilychills all the vapour of the air(which passes over it)into dew.
Q.Why doessnowat the foot of ahedgeorwallmelt sooner, than in an open field?A. Because the hedge or wallradiates heat into the snow beneath, which melts it.
Q.Why doessnowat the foot of ahedgeorwallmelt sooner, than in an open field?
Q.Why doessnowat the foot of ahedgeorwallmelt sooner, than in an open field?
A. Because the hedge or wallradiates heat into the snow beneath, which melts it.
A. Because the hedge or wallradiates heat into the snow beneath, which melts it.
Q.Why is thereno dewafter awindy night?A. 1st—Because the windevaporates the moisture, as fast as it is deposited; and2ndly—Itdisturbs the radiation of heat, and diminishes the deposition of dew thereby.
Q.Why is thereno dewafter awindy night?
Q.Why is thereno dewafter awindy night?
A. 1st—Because the windevaporates the moisture, as fast as it is deposited; and2ndly—Itdisturbs the radiation of heat, and diminishes the deposition of dew thereby.
A. 1st—Because the windevaporates the moisture, as fast as it is deposited; and
2ndly—Itdisturbs the radiation of heat, and diminishes the deposition of dew thereby.
Q.Why areVALLEYS & HOLLOWSoften thickly covered withdew, although they are sheltered?A. The surrounding hills prevent therepose of air(in the valleys)from being disturbed; but do notoverhangandscreenthem, so as toarrest their radiation.
Q.Why areVALLEYS & HOLLOWSoften thickly covered withdew, although they are sheltered?
Q.Why areVALLEYS & HOLLOWSoften thickly covered withdew, although they are sheltered?
A. The surrounding hills prevent therepose of air(in the valleys)from being disturbed; but do notoverhangandscreenthem, so as toarrest their radiation.
A. The surrounding hills prevent therepose of air(in the valleys)from being disturbed; but do notoverhangandscreenthem, so as toarrest their radiation.
Q.Why doesdew fallmoreabundantlyonsome thingsthan uponothers?A. Because some thingsradiate heat more freelythan others, and therefore becomemuch coolerin the night.
Q.Why doesdew fallmoreabundantlyonsome thingsthan uponothers?
Q.Why doesdew fallmoreabundantlyonsome thingsthan uponothers?
A. Because some thingsradiate heat more freelythan others, and therefore becomemuch coolerin the night.
A. Because some thingsradiate heat more freelythan others, and therefore becomemuch coolerin the night.
Q.Why are things whichradiate heat most freely, always the mostthickly coveredwithdew?A. Because the vapour of the air ischilled into dew, the moment it comes in contact with them.
Q.Why are things whichradiate heat most freely, always the mostthickly coveredwithdew?
Q.Why are things whichradiate heat most freely, always the mostthickly coveredwithdew?
A. Because the vapour of the air ischilled into dew, the moment it comes in contact with them.
A. Because the vapour of the air ischilled into dew, the moment it comes in contact with them.
Q.What kind of thingsradiate heatmostfreely?A. Grass, wood, and the leaves of plants, radiate heatvery freely: but polished metal, smooth stones, and woollen cloth, part with their heatvery tardily.
Q.What kind of thingsradiate heatmostfreely?
Q.What kind of thingsradiate heatmostfreely?
A. Grass, wood, and the leaves of plants, radiate heatvery freely: but polished metal, smooth stones, and woollen cloth, part with their heatvery tardily.
A. Grass, wood, and the leaves of plants, radiate heatvery freely: but polished metal, smooth stones, and woollen cloth, part with their heatvery tardily.
Q.Do the leaves ofallplants radiate heatequally well?A. No. Roughwoolly leaves(like those of a holly-hock) radiate heat muchmore freely, than thehard smooth polished leavesof a common laurel.
Q.Do the leaves ofallplants radiate heatequally well?
Q.Do the leaves ofallplants radiate heatequally well?
A. No. Roughwoolly leaves(like those of a holly-hock) radiate heat muchmore freely, than thehard smooth polished leavesof a common laurel.
A. No. Roughwoolly leaves(like those of a holly-hock) radiate heat muchmore freely, than thehard smooth polished leavesof a common laurel.
Q.Shew thewisdomofGodin making grass, the leaves of trees, andall vegetables, excellent radiatorsof heat.A. As vegetablesrequire much moisture, and would often perish without a plentiful deposit of dew, God wisely made them toradiate heat freely, so as tochill the vapour(which touches them)into dew.
Q.Shew thewisdomofGodin making grass, the leaves of trees, andall vegetables, excellent radiatorsof heat.
Q.Shew thewisdomofGodin making grass, the leaves of trees, andall vegetables, excellent radiatorsof heat.
A. As vegetablesrequire much moisture, and would often perish without a plentiful deposit of dew, God wisely made them toradiate heat freely, so as tochill the vapour(which touches them)into dew.
A. As vegetablesrequire much moisture, and would often perish without a plentiful deposit of dew, God wisely made them toradiate heat freely, so as tochill the vapour(which touches them)into dew.
Q.Will polishedmetal, smoothstones, and woollencloth, readily collectdew?A. No. While grass and the leaves of plantsare completely drenched withdew, a piece ofpolished metal, or ofwoollen cloth(lying on the same spot) will bealmost dry.
Q.Will polishedmetal, smoothstones, and woollencloth, readily collectdew?
Q.Will polishedmetal, smoothstones, and woollencloth, readily collectdew?
A. No. While grass and the leaves of plantsare completely drenched withdew, a piece ofpolished metal, or ofwoollen cloth(lying on the same spot) will bealmost dry.
A. No. While grass and the leaves of plantsare completely drenched withdew, a piece ofpolished metal, or ofwoollen cloth(lying on the same spot) will bealmost dry.
Q.Why wouldpolished metalandwoollen clothbedry, while grass and leaves are drenched withdew?A. Because the polished metal and woollen clothpart with their heat so slowly, that the vapour of the air isnot chilled into dewas it passes over them.
Q.Why wouldpolished metalandwoollen clothbedry, while grass and leaves are drenched withdew?
Q.Why wouldpolished metalandwoollen clothbedry, while grass and leaves are drenched withdew?
A. Because the polished metal and woollen clothpart with their heat so slowly, that the vapour of the air isnot chilled into dewas it passes over them.
A. Because the polished metal and woollen clothpart with their heat so slowly, that the vapour of the air isnot chilled into dewas it passes over them.
Q.Why is agravel walkalmostdry, when a grass plat is covered thick withdew?A.Grass, (being a good radiator) throws off its heat veryfreely; butgravel (being a very bad radiator)parts with its heat veryreluctantly.
Q.Why is agravel walkalmostdry, when a grass plat is covered thick withdew?
Q.Why is agravel walkalmostdry, when a grass plat is covered thick withdew?
A.Grass, (being a good radiator) throws off its heat veryfreely; butgravel (being a very bad radiator)parts with its heat veryreluctantly.
A.Grass, (being a good radiator) throws off its heat veryfreely; butgravel (being a very bad radiator)parts with its heat veryreluctantly.
Q.Is that the reason whygrassissaturatedwithdew, and thegravelisnot?A. Yes. When the vapour of warm air comes in contact with thecold grass, it is instantly chilled into dew; but (as the gravel isnot so cold as the grass) the vapour of air isnot so freely condensedas it passes over the gravel.
Q.Is that the reason whygrassissaturatedwithdew, and thegravelisnot?
Q.Is that the reason whygrassissaturatedwithdew, and thegravelisnot?
A. Yes. When the vapour of warm air comes in contact with thecold grass, it is instantly chilled into dew; but (as the gravel isnot so cold as the grass) the vapour of air isnot so freely condensedas it passes over the gravel.
A. Yes. When the vapour of warm air comes in contact with thecold grass, it is instantly chilled into dew; but (as the gravel isnot so cold as the grass) the vapour of air isnot so freely condensedas it passes over the gravel.
Q.Why doesdewrarely fall upon hardrocksandbarrenlands?A. Rocks and barren lands are socompactandhard, that they can neitherabsorb nor radiate much heat; and (as theirtemperature varies but very little) very littledewdistils upon them.
Q.Why doesdewrarely fall upon hardrocksandbarrenlands?
Q.Why doesdewrarely fall upon hardrocksandbarrenlands?
A. Rocks and barren lands are socompactandhard, that they can neitherabsorb nor radiate much heat; and (as theirtemperature varies but very little) very littledewdistils upon them.
A. Rocks and barren lands are socompactandhard, that they can neitherabsorb nor radiate much heat; and (as theirtemperature varies but very little) very littledewdistils upon them.
Q.Why doesdewfall more abundantly oncultivatedsoils, than onbarrenlands?A. Because cultivated soils (beingloose and porous)absorbheat freely during the day, andradiate itby night; and (beingmuch cooled by the rapid radiation of heat) as the vapour of the air passes over them, it is plentifullycondensed into dew.
Q.Why doesdewfall more abundantly oncultivatedsoils, than onbarrenlands?
Q.Why doesdewfall more abundantly oncultivatedsoils, than onbarrenlands?
A. Because cultivated soils (beingloose and porous)absorbheat freely during the day, andradiate itby night; and (beingmuch cooled by the rapid radiation of heat) as the vapour of the air passes over them, it is plentifullycondensed into dew.
A. Because cultivated soils (beingloose and porous)absorbheat freely during the day, andradiate itby night; and (beingmuch cooled by the rapid radiation of heat) as the vapour of the air passes over them, it is plentifullycondensed into dew.
Q.Shew thewisdomofGodin this arrangement.A. Every plant and inch of land whichneeds the moisture of dew, is adapted tocollect it; butnot a single drop even of dew is wasted, where its refreshing moisture isnot required.
Q.Shew thewisdomofGodin this arrangement.
Q.Shew thewisdomofGodin this arrangement.
A. Every plant and inch of land whichneeds the moisture of dew, is adapted tocollect it; butnot a single drop even of dew is wasted, where its refreshing moisture isnot required.
A. Every plant and inch of land whichneeds the moisture of dew, is adapted tocollect it; butnot a single drop even of dew is wasted, where its refreshing moisture isnot required.
Q.Shew thewisdomofGodin making polishedmetaland woollencloth bad radiatorsof heat.A. If polished metal collected dew as easily as grass, it couldnever be kept dry,andfree from rust. Again, if woollen garments collected dew as readily as the leaves of trees, we should beoften soaking wet, and subject toconstant colds.
Q.Shew thewisdomofGodin making polishedmetaland woollencloth bad radiatorsof heat.
Q.Shew thewisdomofGodin making polishedmetaland woollencloth bad radiatorsof heat.
A. If polished metal collected dew as easily as grass, it couldnever be kept dry,andfree from rust. Again, if woollen garments collected dew as readily as the leaves of trees, we should beoften soaking wet, and subject toconstant colds.
A. If polished metal collected dew as easily as grass, it couldnever be kept dry,andfree from rust. Again, if woollen garments collected dew as readily as the leaves of trees, we should beoften soaking wet, and subject toconstant colds.
Q.Shew how this affords a beautiful illustration ofGideon’s miracle, recorded in the book of Judges,VI. 37, 38.A. Thefleece of wool(which is avery bad radiatorof heat) wassoaking wetwith dew: when thegrass(which is a mostexcellent radiator) wasquite dry.
Q.Shew how this affords a beautiful illustration ofGideon’s miracle, recorded in the book of Judges,VI. 37, 38.
Q.Shew how this affords a beautiful illustration ofGideon’s miracle, recorded in the book of Judges,VI. 37, 38.
A. Thefleece of wool(which is avery bad radiatorof heat) wassoaking wetwith dew: when thegrass(which is a mostexcellent radiator) wasquite dry.
A. Thefleece of wool(which is avery bad radiatorof heat) wassoaking wetwith dew: when thegrass(which is a mostexcellent radiator) wasquite dry.
Q.Was not thiscontraryto the laws ofnature?A. Yes; and was, therefore, a plaindemonstration of the power of God, who could change the verynature of thingsat his will.
Q.Was not thiscontraryto the laws ofnature?
Q.Was not thiscontraryto the laws ofnature?
A. Yes; and was, therefore, a plaindemonstration of the power of God, who could change the verynature of thingsat his will.
A. Yes; and was, therefore, a plaindemonstration of the power of God, who could change the verynature of thingsat his will.
Q.Why do ourclothes feel damp, after walking in a fine evening inspringorautumn?A. Because the vapour (condensed by the cold earth) lights upon them, like dew.
Q.Why do ourclothes feel damp, after walking in a fine evening inspringorautumn?
Q.Why do ourclothes feel damp, after walking in a fine evening inspringorautumn?
A. Because the vapour (condensed by the cold earth) lights upon them, like dew.
A. Because the vapour (condensed by the cold earth) lights upon them, like dew.
Q.Why arewindowsoften covered with thickmist, and the frames wet with standingwater?A. The temperature of theexternal airalwaysfalls at sun-set, andchillsthe window-glass, with which it comes in contact.
Q.Why arewindowsoften covered with thickmist, and the frames wet with standingwater?
Q.Why arewindowsoften covered with thickmist, and the frames wet with standingwater?
A. The temperature of theexternal airalwaysfalls at sun-set, andchillsthe window-glass, with which it comes in contact.
A. The temperature of theexternal airalwaysfalls at sun-set, andchillsthe window-glass, with which it comes in contact.
Q.How does this account for themistandwateron awindow?A. As the warm vapour of the roomtouches the cold glass, it ischilledandcondensed into mist; and the mist (collecting into drops)rolls down the window-framein little streams of water.
Q.How does this account for themistandwateron awindow?
Q.How does this account for themistandwateron awindow?
A. As the warm vapour of the roomtouches the cold glass, it ischilledandcondensed into mist; and the mist (collecting into drops)rolls down the window-framein little streams of water.
A. As the warm vapour of the roomtouches the cold glass, it ischilledandcondensed into mist; and the mist (collecting into drops)rolls down the window-framein little streams of water.
Q.Does theglassof a windowcooldown morerapidlythan theairof the room itself?A. Yes; because the air iskept warm by fires, and theanimal heatof the people in the room; in consequence of which, theair of a room suffers very little diminution of heatfrom the setting of the sun.
Q.Does theglassof a windowcooldown morerapidlythan theairof the room itself?
Q.Does theglassof a windowcooldown morerapidlythan theairof the room itself?
A. Yes; because the air iskept warm by fires, and theanimal heatof the people in the room; in consequence of which, theair of a room suffers very little diminution of heatfrom the setting of the sun.
A. Yes; because the air iskept warm by fires, and theanimal heatof the people in the room; in consequence of which, theair of a room suffers very little diminution of heatfrom the setting of the sun.
Q.Whence arises thevapourof aroom?A. 1st—The veryairof the roomcontains vapour:2ndly—Thebreathandinsensible perspirationof the inmatesincreasethis vapour: and3rdly—Hot dinners, thesteam of tea, &c. contribute toincrease it still more.
Q.Whence arises thevapourof aroom?
Q.Whence arises thevapourof aroom?
A. 1st—The veryairof the roomcontains vapour:2ndly—Thebreathandinsensible perspirationof the inmatesincreasethis vapour: and3rdly—Hot dinners, thesteam of tea, &c. contribute toincrease it still more.
A. 1st—The veryairof the roomcontains vapour:
2ndly—Thebreathandinsensible perspirationof the inmatesincreasethis vapour: and
3rdly—Hot dinners, thesteam of tea, &c. contribute toincrease it still more.
Q.What is meant by “theinsensible perspiration?”A. From every part of the human body aninsensible and invisible perspiration issuesall night and day; not only in the hot weather ofsummer, but also in the coldest day ofwinter.
Q.What is meant by “theinsensible perspiration?”
Q.What is meant by “theinsensible perspiration?”
A. From every part of the human body aninsensible and invisible perspiration issuesall night and day; not only in the hot weather ofsummer, but also in the coldest day ofwinter.
A. From every part of the human body aninsensible and invisible perspiration issuesall night and day; not only in the hot weather ofsummer, but also in the coldest day ofwinter.
Q.If the perspiration be bothinsensibleandinvisible, how is itknownthat thereisany such perspiration?A. If you put your naked arminto a clean dry glass cylinder, theperspirationof your arm will sooncondenseon the glass, like mist.
Q.If the perspiration be bothinsensibleandinvisible, how is itknownthat thereisany such perspiration?
Q.If the perspiration be bothinsensibleandinvisible, how is itknownthat thereisany such perspiration?
A. If you put your naked arminto a clean dry glass cylinder, theperspirationof your arm will sooncondenseon the glass, like mist.
A. If you put your naked arminto a clean dry glass cylinder, theperspirationof your arm will sooncondenseon the glass, like mist.
Q.Why arecarriage windowsverysooncovered with thickmist?A. The warm vapour of the carriageis condensed the moment it touches the cold glass, and covers it over with a thick mist.
Q.Why arecarriage windowsverysooncovered with thickmist?
Q.Why arecarriage windowsverysooncovered with thickmist?
A. The warm vapour of the carriageis condensed the moment it touches the cold glass, and covers it over with a thick mist.
A. The warm vapour of the carriageis condensed the moment it touches the cold glass, and covers it over with a thick mist.
Q.Why is the glass windowcoldenough to condense the vapour of the carriage?A. Because theinsideof the carriage is muchwarmerthan theoutside, and the glass window is made cold by contact with theexternal air.
Q.Why is the glass windowcoldenough to condense the vapour of the carriage?
Q.Why is the glass windowcoldenough to condense the vapour of the carriage?
A. Because theinsideof the carriage is muchwarmerthan theoutside, and the glass window is made cold by contact with theexternal air.
A. Because theinsideof the carriage is muchwarmerthan theoutside, and the glass window is made cold by contact with theexternal air.
Q.Where does thewarmvapour of the carriage come from?A. The warmbreathandinsensible perspirationof the persons riding in the carriage, load the air of it with warm vapour.
Q.Where does thewarmvapour of the carriage come from?
Q.Where does thewarmvapour of the carriage come from?
A. The warmbreathandinsensible perspirationof the persons riding in the carriage, load the air of it with warm vapour.
A. The warmbreathandinsensible perspirationof the persons riding in the carriage, load the air of it with warm vapour.
Q.What is the cause of the prettyfrost-workseen on bed-roomwindowsin winter-time?A. Thebreathandinsensible perspirationof the sleeper (coming in contact with the ice-cold window) isfrozenby the cold glass, and forms those beautiful appearances seen in our bed-rooms in a winter morning.
Q.What is the cause of the prettyfrost-workseen on bed-roomwindowsin winter-time?
Q.What is the cause of the prettyfrost-workseen on bed-roomwindowsin winter-time?
A. Thebreathandinsensible perspirationof the sleeper (coming in contact with the ice-cold window) isfrozenby the cold glass, and forms those beautiful appearances seen in our bed-rooms in a winter morning.
A. Thebreathandinsensible perspirationof the sleeper (coming in contact with the ice-cold window) isfrozenby the cold glass, and forms those beautiful appearances seen in our bed-rooms in a winter morning.
Q.Why is theglassof a window colder than thewallsof a room?A. Glass is a veryexcellent radiator; and, therefore, mostrapidly parts with its heat.
Q.Why is theglassof a window colder than thewallsof a room?
Q.Why is theglassof a window colder than thewallsof a room?
A. Glass is a veryexcellent radiator; and, therefore, mostrapidly parts with its heat.
A. Glass is a veryexcellent radiator; and, therefore, mostrapidly parts with its heat.
Q.Why is atumblerof coldwatermade quitedullwith mist, when brought into a roomfullofpeople?A. Because thehot vapour of the room(coming in contact with the cold tumbler)is condensed upon it; and changes its invisible and gaseous form for that of athick mist.
Q.Why is atumblerof coldwatermade quitedullwith mist, when brought into a roomfullofpeople?
Q.Why is atumblerof coldwatermade quitedullwith mist, when brought into a roomfullofpeople?
A. Because thehot vapour of the room(coming in contact with the cold tumbler)is condensed upon it; and changes its invisible and gaseous form for that of athick mist.
A. Because thehot vapour of the room(coming in contact with the cold tumbler)is condensed upon it; and changes its invisible and gaseous form for that of athick mist.
Q.Why is aglassmade quitedull, by laying ahot handupon it?A. Theinsensible perspirationof the hot hand iscondensedupon the cold glass, and thus made perceptible.
Q.Why is aglassmade quitedull, by laying ahot handupon it?
Q.Why is aglassmade quitedull, by laying ahot handupon it?
A. Theinsensible perspirationof the hot hand iscondensedupon the cold glass, and thus made perceptible.
A. Theinsensible perspirationof the hot hand iscondensedupon the cold glass, and thus made perceptible.
Q.Why arewine-glassesmade quitedullwhen they are brought into a roomfullofcompany?A. Thehot vapour of the room(coming in contact with the cold wine-glasses)is condensedupon them, and covers them with vapour like dew.
Q.Why arewine-glassesmade quitedullwhen they are brought into a roomfullofcompany?
Q.Why arewine-glassesmade quitedullwhen they are brought into a roomfullofcompany?
A. Thehot vapour of the room(coming in contact with the cold wine-glasses)is condensedupon them, and covers them with vapour like dew.
A. Thehot vapour of the room(coming in contact with the cold wine-glasses)is condensedupon them, and covers them with vapour like dew.
Q.Why does this misty appearancego offafter a little time?A. Because the glass becomes of thesame temperatureas theair of the room, and will no longerchill the vapourwhich touches it, andcondense it into mist.
Q.Why does this misty appearancego offafter a little time?
Q.Why does this misty appearancego offafter a little time?
A. Because the glass becomes of thesame temperatureas theair of the room, and will no longerchill the vapourwhich touches it, andcondense it into mist.
A. Because the glass becomes of thesame temperatureas theair of the room, and will no longerchill the vapourwhich touches it, andcondense it into mist.
Q.Why is awine-glass(brought out of acellarinto theair) covered with a thickmistin summer-time?A. The vapour of the hot air iscondensedby the cold glass, and covers it as a thick mist.
Q.Why is awine-glass(brought out of acellarinto theair) covered with a thickmistin summer-time?
Q.Why is awine-glass(brought out of acellarinto theair) covered with a thickmistin summer-time?
A. The vapour of the hot air iscondensedby the cold glass, and covers it as a thick mist.
A. The vapour of the hot air iscondensedby the cold glass, and covers it as a thick mist.
Q.Why doesbreathingon aglassmake it quitedull?A. Because the hot breath iscondensedby the cold glass; and, therefore, covers it with a thick mist.
Q.Why doesbreathingon aglassmake it quitedull?
Q.Why doesbreathingon aglassmake it quitedull?
A. Because the hot breath iscondensedby the cold glass; and, therefore, covers it with a thick mist.
A. Because the hot breath iscondensedby the cold glass; and, therefore, covers it with a thick mist.
Q.Why dowallsstand thick withwetin a suddenthaw?A. The walls (being thick) cannotchange their temperature so fastas the thin air can; and, therefore, theyretain their coldafter the thaw has set in.
Q.Why dowallsstand thick withwetin a suddenthaw?
Q.Why dowallsstand thick withwetin a suddenthaw?
A. The walls (being thick) cannotchange their temperature so fastas the thin air can; and, therefore, theyretain their coldafter the thaw has set in.
A. The walls (being thick) cannotchange their temperature so fastas the thin air can; and, therefore, theyretain their coldafter the thaw has set in.
Q.How doesretainingtheircoldaccount for their being sowet?A. As the vapour of the warm airtouches the cold wall, it ischilledandcondensed into water, whichsticks to the wall, and sometimes trickles down in little streams.
Q.How doesretainingtheircoldaccount for their being sowet?
Q.How doesretainingtheircoldaccount for their being sowet?
A. As the vapour of the warm airtouches the cold wall, it ischilledandcondensed into water, whichsticks to the wall, and sometimes trickles down in little streams.
A. As the vapour of the warm airtouches the cold wall, it ischilledandcondensed into water, whichsticks to the wall, and sometimes trickles down in little streams.
Q.Why does a thickwell-built housecontract moredampof this kind, than anordinaryone?A. Because the walls are muchthicker; and (if the frost has penetratedfar into the bricks) it takes a long time to reduce them to thesame temperature as the air.
Q.Why does a thickwell-built housecontract moredampof this kind, than anordinaryone?
Q.Why does a thickwell-built housecontract moredampof this kind, than anordinaryone?
A. Because the walls are muchthicker; and (if the frost has penetratedfar into the bricks) it takes a long time to reduce them to thesame temperature as the air.
A. Because the walls are muchthicker; and (if the frost has penetratedfar into the bricks) it takes a long time to reduce them to thesame temperature as the air.
Q.Why arebanisters, &c.dampafter athaw?A. The wooden banister (being made of some very close-grained, varnished wood) cannotchange its temperature so fastas the air; and, therefore,remains coldsome time after the thaw has set in.
Q.Why arebanisters, &c.dampafter athaw?
Q.Why arebanisters, &c.dampafter athaw?
A. The wooden banister (being made of some very close-grained, varnished wood) cannotchange its temperature so fastas the air; and, therefore,remains coldsome time after the thaw has set in.
A. The wooden banister (being made of some very close-grained, varnished wood) cannotchange its temperature so fastas the air; and, therefore,remains coldsome time after the thaw has set in.
Q.How doesthisaccount for thebanistersbeingdamp?A. The vapour of the warm air (coming in contact with the cold banister) ischilled, and condensed intowater upon it.
Q.How doesthisaccount for thebanistersbeingdamp?
Q.How doesthisaccount for thebanistersbeingdamp?
A. The vapour of the warm air (coming in contact with the cold banister) ischilled, and condensed intowater upon it.
A. The vapour of the warm air (coming in contact with the cold banister) ischilled, and condensed intowater upon it.
Q.Why is ourbreath visibleinwinterandnotinsummer?A. Inwinterthe coldness of the air condenses our breath intovisible vapour; but insummerthe air isnot cold enoughto condense it into visible vapour.
Q.Why is ourbreath visibleinwinterandnotinsummer?
Q.Why is ourbreath visibleinwinterandnotinsummer?
A. Inwinterthe coldness of the air condenses our breath intovisible vapour; but insummerthe air isnot cold enoughto condense it into visible vapour.
A. Inwinterthe coldness of the air condenses our breath intovisible vapour; but insummerthe air isnot cold enoughto condense it into visible vapour.
Q.Why are ourhairand thebrimof ourhatoften covered with little drops of pearlydewin winter-time?A. The breath (issuing from our mouth and nose)is condensed into drops, as it comes in contact with our cold hair or hat; and (being condensed) hangs there in little dew-drops.
Q.Why are ourhairand thebrimof ourhatoften covered with little drops of pearlydewin winter-time?
Q.Why are ourhairand thebrimof ourhatoften covered with little drops of pearlydewin winter-time?
A. The breath (issuing from our mouth and nose)is condensed into drops, as it comes in contact with our cold hair or hat; and (being condensed) hangs there in little dew-drops.
A. The breath (issuing from our mouth and nose)is condensed into drops, as it comes in contact with our cold hair or hat; and (being condensed) hangs there in little dew-drops.
Q.Why does thesteamof arailway boileroften pour down, like fine rain, when the steam is “let off?”A. The steam from the steam-pipe (when the air is cold)is condensed by contact with the chill air, and falls like fine rain.
Q.Why does thesteamof arailway boileroften pour down, like fine rain, when the steam is “let off?”
Q.Why does thesteamof arailway boileroften pour down, like fine rain, when the steam is “let off?”
A. The steam from the steam-pipe (when the air is cold)is condensed by contact with the chill air, and falls like fine rain.
A. The steam from the steam-pipe (when the air is cold)is condensed by contact with the chill air, and falls like fine rain.
Q.Why is thereless dewwhen thewindiseasterly, than when the wind iswesterly?A.Easterlywinds cross thecontinent of Europe, and, (as they pass overland) aredryandarid; butwesterlywinds cross theAtlantic Ocean; and (as they pass overwater) aremoistandfull of vapour.
Q.Why is thereless dewwhen thewindiseasterly, than when the wind iswesterly?
Q.Why is thereless dewwhen thewindiseasterly, than when the wind iswesterly?
A.Easterlywinds cross thecontinent of Europe, and, (as they pass overland) aredryandarid; butwesterlywinds cross theAtlantic Ocean; and (as they pass overwater) aremoistandfull of vapour.
A.Easterlywinds cross thecontinent of Europe, and, (as they pass overland) aredryandarid; butwesterlywinds cross theAtlantic Ocean; and (as they pass overwater) aremoistandfull of vapour.
Q.How does thedrynessof an eastern windprevent dew-falls?A. As the easterly winds aredry, theyimbibethe moisture of the air; and, therefore, thereis very littleleft to be condensed intodew.
Q.How does thedrynessof an eastern windprevent dew-falls?
Q.How does thedrynessof an eastern windprevent dew-falls?
A. As the easterly winds aredry, theyimbibethe moisture of the air; and, therefore, thereis very littleleft to be condensed intodew.
A. As the easterly winds aredry, theyimbibethe moisture of the air; and, therefore, thereis very littleleft to be condensed intodew.
Q.How does themoistnessof a western windpromotedew-falls?A. As the westerly winds aresaturated with vapour, they require avery little reduction of heatto cause acopious deposition of dew.
Q.How does themoistnessof a western windpromotedew-falls?
Q.How does themoistnessof a western windpromotedew-falls?
A. As the westerly winds aresaturated with vapour, they require avery little reduction of heatto cause acopious deposition of dew.
A. As the westerly winds aresaturated with vapour, they require avery little reduction of heatto cause acopious deposition of dew.
Q.When isdewmostcopiouslydistilled?A. After a hot day in summer or autumn, with thewind in the west.
Q.When isdewmostcopiouslydistilled?
Q.When isdewmostcopiouslydistilled?
A. After a hot day in summer or autumn, with thewind in the west.
A. After a hot day in summer or autumn, with thewind in the west.
Q.Why isdewdistilled mostcopiouslyafter ahotday?A. Because the surface of the earthradiatesheat very freely at sunset; and (becoming thusmuch colder than the air)chills its vapour, and condenses it into dew.
Q.Why isdewdistilled mostcopiouslyafter ahotday?
Q.Why isdewdistilled mostcopiouslyafter ahotday?
A. Because the surface of the earthradiatesheat very freely at sunset; and (becoming thusmuch colder than the air)chills its vapour, and condenses it into dew.
A. Because the surface of the earthradiatesheat very freely at sunset; and (becoming thusmuch colder than the air)chills its vapour, and condenses it into dew.
Q.Does notairradiate heat, as well as theearthand its various plants?A. No. The airnever radiates heat, nor is the air itselfmade hotby therays of the sun.
Q.Does notairradiate heat, as well as theearthand its various plants?
Q.Does notairradiate heat, as well as theearthand its various plants?
A. No. The airnever radiates heat, nor is the air itselfmade hotby therays of the sun.
A. No. The airnever radiates heat, nor is the air itselfmade hotby therays of the sun.
Q.How is theairmadehotorcold?A. Byconvection of hot or cold currents.
Q.How is theairmadehotorcold?
Q.How is theairmadehotorcold?
A. Byconvection of hot or cold currents.
A. Byconvection of hot or cold currents.
Q.What is meant by “convectionof hot and cold currents?”A. The air (which is heated by the surface of the earth)ascends, warming the airthrough which it passes.Otherair (being warmed in a similar way)also ascends, carrying heat; tillall the airis made hot.
Q.What is meant by “convectionof hot and cold currents?”
Q.What is meant by “convectionof hot and cold currents?”
A. The air (which is heated by the surface of the earth)ascends, warming the airthrough which it passes.Otherair (being warmed in a similar way)also ascends, carrying heat; tillall the airis made hot.
A. The air (which is heated by the surface of the earth)ascends, warming the airthrough which it passes.Otherair (being warmed in a similar way)also ascends, carrying heat; tillall the airis made hot.
Q.Is theairmadecoldin a similar way?A. Yes. The air resting on the earth ismade cold by contact: this cold air makes theair above it cold; and cold currents or windsshake the whole together, till all becomes of one temperature.
Q.Is theairmadecoldin a similar way?
Q.Is theairmadecoldin a similar way?
A. Yes. The air resting on the earth ismade cold by contact: this cold air makes theair above it cold; and cold currents or windsshake the whole together, till all becomes of one temperature.
A. Yes. The air resting on the earth ismade cold by contact: this cold air makes theair above it cold; and cold currents or windsshake the whole together, till all becomes of one temperature.
Q.Why ismeatvery subject totainton amoon-lightnight?A. In a bright moon-light night,meat radiates heat very freely; and is, therefore, sooncovered with dew, which producesrapid decomposition.
Q.Why ismeatvery subject totainton amoon-lightnight?
Q.Why ismeatvery subject totainton amoon-lightnight?
A. In a bright moon-light night,meat radiates heat very freely; and is, therefore, sooncovered with dew, which producesrapid decomposition.
A. In a bright moon-light night,meat radiates heat very freely; and is, therefore, sooncovered with dew, which producesrapid decomposition.
Q.Why doplants grow rapidlyinmoon-lightnights?A. In bright moon-light nightsrapid radiation is carried on, anddew is plentifully depositedon young plants, which conduces much to their growth and vigour.
Q.Why doplants grow rapidlyinmoon-lightnights?
Q.Why doplants grow rapidlyinmoon-lightnights?
A. In bright moon-light nightsrapid radiation is carried on, anddew is plentifully depositedon young plants, which conduces much to their growth and vigour.
A. In bright moon-light nightsrapid radiation is carried on, anddew is plentifully depositedon young plants, which conduces much to their growth and vigour.
Q.Why is eveningdew injurioustohealth?A. Because the condensed vapours are always laden withnoxious exhalations from the earth: this is especially the case inmarshycountries.
Q.Why is eveningdew injurioustohealth?
Q.Why is eveningdew injurioustohealth?
A. Because the condensed vapours are always laden withnoxious exhalations from the earth: this is especially the case inmarshycountries.
A. Because the condensed vapours are always laden withnoxious exhalations from the earth: this is especially the case inmarshycountries.
Q.Ishoney-dewa similar thing todew?A. No. Honey-dew is a sweet liquidshed by a very small insect(called the aphis), and deposited in autumnon the under surfaceof favourite leaves.
Q.Ishoney-dewa similar thing todew?
Q.Ishoney-dewa similar thing todew?
A. No. Honey-dew is a sweet liquidshed by a very small insect(called the aphis), and deposited in autumnon the under surfaceof favourite leaves.
A. No. Honey-dew is a sweet liquidshed by a very small insect(called the aphis), and deposited in autumnon the under surfaceof favourite leaves.
Q.Doeshoney-dew injureleaves, or do them good?A. It injures them very much, because itfills the poresof the leaf with athick clammy liquid; and, therefore, prevents the leaf fromtranspiring and absorbing.
Q.Doeshoney-dew injureleaves, or do them good?
Q.Doeshoney-dew injureleaves, or do them good?
A. It injures them very much, because itfills the poresof the leaf with athick clammy liquid; and, therefore, prevents the leaf fromtranspiring and absorbing.
A. It injures them very much, because itfills the poresof the leaf with athick clammy liquid; and, therefore, prevents the leaf fromtranspiring and absorbing.
Q.Whateffecthas honey-dew upon theappearanceof a leaf?A. After a little time, the leaf (beingsmotheredandstarved) begins to turn adingy yellow.
Q.Whateffecthas honey-dew upon theappearanceof a leaf?
Q.Whateffecthas honey-dew upon theappearanceof a leaf?
A. After a little time, the leaf (beingsmotheredandstarved) begins to turn adingy yellow.
A. After a little time, the leaf (beingsmotheredandstarved) begins to turn adingy yellow.
Q.Are notantsveryfondofhoney-dew?A. Yes; and they crawl up the loftiest trees, in order to obtain it.
Q.Are notantsveryfondofhoney-dew?
Q.Are notantsveryfondofhoney-dew?
A. Yes; and they crawl up the loftiest trees, in order to obtain it.
A. Yes; and they crawl up the loftiest trees, in order to obtain it.
Q.What is the cause ofmist(or earth-fog)?A. If thenight has been very calm, arapidradiation of heat has taken place in the earth; in consequence of which, theair(resting on the earth)is made so cold, that its vapour ischilled, and condensed into a thick mist.
Q.What is the cause ofmist(or earth-fog)?
Q.What is the cause ofmist(or earth-fog)?
A. If thenight has been very calm, arapidradiation of heat has taken place in the earth; in consequence of which, theair(resting on the earth)is made so cold, that its vapour ischilled, and condensed into a thick mist.
A. If thenight has been very calm, arapidradiation of heat has taken place in the earth; in consequence of which, theair(resting on the earth)is made so cold, that its vapour ischilled, and condensed into a thick mist.
Q.Why does not themistbecomedew?A. Because the chill of the airis so rapid, that vapour is condensedfaster than it can be deposited; and (covering the earth in a mist)prevents any further radiation of heatfrom the earth.
Q.Why does not themistbecomedew?
Q.Why does not themistbecomedew?
A. Because the chill of the airis so rapid, that vapour is condensedfaster than it can be deposited; and (covering the earth in a mist)prevents any further radiation of heatfrom the earth.
A. Because the chill of the airis so rapid, that vapour is condensedfaster than it can be deposited; and (covering the earth in a mist)prevents any further radiation of heatfrom the earth.
Q.When the earth can no longerradiateheat upwards, does it continue tocondensethe vapour of the air?A. No; the air (in contact with the earth) becomes aboutequal in temperaturewith the surface of the earth itself; for which reason, the mist isnot condensed into dew, but remainsfloating above the earthas a thick cloud.
Q.When the earth can no longerradiateheat upwards, does it continue tocondensethe vapour of the air?
Q.When the earth can no longerradiateheat upwards, does it continue tocondensethe vapour of the air?
A. No; the air (in contact with the earth) becomes aboutequal in temperaturewith the surface of the earth itself; for which reason, the mist isnot condensed into dew, but remainsfloating above the earthas a thick cloud.
A. No; the air (in contact with the earth) becomes aboutequal in temperaturewith the surface of the earth itself; for which reason, the mist isnot condensed into dew, but remainsfloating above the earthas a thick cloud.
Q.Why does thismistseem torise higherandhigher, and yet remain quite as dense below as before?A. The airresting on the earthis first chilled, andchills the airresting onit; the air which touchesthis new layer of mistbeing alsocondensed, layer is added to layer; and the mist seems to berising, when (in fact) it is onlydeepening.
Q.Why does thismistseem torise higherandhigher, and yet remain quite as dense below as before?
Q.Why does thismistseem torise higherandhigher, and yet remain quite as dense below as before?
A. The airresting on the earthis first chilled, andchills the airresting onit; the air which touchesthis new layer of mistbeing alsocondensed, layer is added to layer; and the mist seems to berising, when (in fact) it is onlydeepening.
A. The airresting on the earthis first chilled, andchills the airresting onit; the air which touchesthis new layer of mistbeing alsocondensed, layer is added to layer; and the mist seems to berising, when (in fact) it is onlydeepening.
Q.Why doesmistanddew vanishas thesunrises?A. Because the condensed vapour isagain rarefied by the heat of the sun, and separated into invisible particles.
Q.Why doesmistanddew vanishas thesunrises?
Q.Why doesmistanddew vanishas thesunrises?
A. Because the condensed vapour isagain rarefied by the heat of the sun, and separated into invisible particles.
A. Because the condensed vapour isagain rarefied by the heat of the sun, and separated into invisible particles.
Q.Why is adew-drop round?A. Because every part of the dropis equally balanced; and, therefore, there is no cause whyone partof the dropshould be further from the centrethananother.
Q.Why is adew-drop round?
Q.Why is adew-drop round?
A. Because every part of the dropis equally balanced; and, therefore, there is no cause whyone partof the dropshould be further from the centrethananother.
A. Because every part of the dropis equally balanced; and, therefore, there is no cause whyone partof the dropshould be further from the centrethananother.
Q.Why is thedew-dropon a broad leaf sometimesflattened?A. Whenever two or more drops of dewroll together, they make one largespheroid(or flattened drop).
Q.Why is thedew-dropon a broad leaf sometimesflattened?
Q.Why is thedew-dropon a broad leaf sometimesflattened?
A. Whenever two or more drops of dewroll together, they make one largespheroid(or flattened drop).
A. Whenever two or more drops of dewroll together, they make one largespheroid(or flattened drop).
Q.Why willDEW-DROPS ROLL ABOUT CABBAGE-PLANTS, POPPIES, &c. without wetting the surface?A. The leaves of cabbages and poppies arecovered with a very fine powder; and the dew-drop rolls over this fine powder, as a drop of rainover dust, without wetting the surface.
Q.Why willDEW-DROPS ROLL ABOUT CABBAGE-PLANTS, POPPIES, &c. without wetting the surface?
Q.Why willDEW-DROPS ROLL ABOUT CABBAGE-PLANTS, POPPIES, &c. without wetting the surface?
A. The leaves of cabbages and poppies arecovered with a very fine powder; and the dew-drop rolls over this fine powder, as a drop of rainover dust, without wetting the surface.
A. The leaves of cabbages and poppies arecovered with a very fine powder; and the dew-drop rolls over this fine powder, as a drop of rainover dust, without wetting the surface.
Q.Why does not the drop ofrain wetthedustover which it rolls?A. Because it is driven from grain to grain bycapillary repulsion.
Q.Why does not the drop ofrain wetthedustover which it rolls?
Q.Why does not the drop ofrain wetthedustover which it rolls?
A. Because it is driven from grain to grain bycapillary repulsion.
A. Because it is driven from grain to grain bycapillary repulsion.
Q.Why does not thedew-drop wetthepowderof thecabbage-plant?A. Because it is driven from grain to grain bycapillary repulsion.
Q.Why does not thedew-drop wetthepowderof thecabbage-plant?
Q.Why does not thedew-drop wetthepowderof thecabbage-plant?
A. Because it is driven from grain to grain bycapillary repulsion.
A. Because it is driven from grain to grain bycapillary repulsion.
Q.Why willdew-drops rolloverroses, &c. without wetting their petals?A. The leaves of a rosecontain an essential oil, which prevents them from absorbing the dew immediately.
Q.Why willdew-drops rolloverroses, &c. without wetting their petals?
Q.Why willdew-drops rolloverroses, &c. without wetting their petals?
A. The leaves of a rosecontain an essential oil, which prevents them from absorbing the dew immediately.
A. The leaves of a rosecontain an essential oil, which prevents them from absorbing the dew immediately.
Q.Why can aswanorduckdive under waterwithoutbeingwetted?A. Because their feathers are coveredwith an oily secretion, which repels the water.
Q.Why can aswanorduckdive under waterwithoutbeingwetted?
Q.Why can aswanorduckdive under waterwithoutbeingwetted?
A. Because their feathers are coveredwith an oily secretion, which repels the water.
A. Because their feathers are coveredwith an oily secretion, which repels the water.
Q.What is the cause ofmist?A. When currents of airfrom landmix with currents of airfrom water, the currentsfrom the water are condensed into mistby the colder currentsblowing from the land.
Q.What is the cause ofmist?
Q.What is the cause ofmist?
A. When currents of airfrom landmix with currents of airfrom water, the currentsfrom the water are condensed into mistby the colder currentsblowing from the land.
A. When currents of airfrom landmix with currents of airfrom water, the currentsfrom the water are condensed into mistby the colder currentsblowing from the land.
Q.Why are the currents of air from theland colderthan those blowing overwater?A. Because the earthradiates heat very freely, and (being greatly cooled down)cools the air alsowhich comes in contact with it.
Q.Why are the currents of air from theland colderthan those blowing overwater?
Q.Why are the currents of air from theland colderthan those blowing overwater?
A. Because the earthradiates heat very freely, and (being greatly cooled down)cools the air alsowhich comes in contact with it.
A. Because the earthradiates heat very freely, and (being greatly cooled down)cools the air alsowhich comes in contact with it.
Q.Why is not theair, which passes overwater, socoolas that which passes overland?A. Becausewater does not cool down at sun-set, so fast as thelanddoes; and, therefore, the air in contact with it iswarmer.
Q.Why is not theair, which passes overwater, socoolas that which passes overland?
Q.Why is not theair, which passes overwater, socoolas that which passes overland?
A. Becausewater does not cool down at sun-set, so fast as thelanddoes; and, therefore, the air in contact with it iswarmer.
A. Becausewater does not cool down at sun-set, so fast as thelanddoes; and, therefore, the air in contact with it iswarmer.
Q.Why does notwatercool down so fast asland?A. 1st—Because thesurfaceof water isperpetually changing, and as fast asonesurface is made cold,anotheris presented: and2ndly—The moment water is made coldit sinks, andwarmer portions of water rise to occupy its place: therefore, before thesurface of water is cooled, thewhole volumemust be made cold; which is not the case with land.
Q.Why does notwatercool down so fast asland?
Q.Why does notwatercool down so fast asland?
A. 1st—Because thesurfaceof water isperpetually changing, and as fast asonesurface is made cold,anotheris presented: and2ndly—The moment water is made coldit sinks, andwarmer portions of water rise to occupy its place: therefore, before thesurface of water is cooled, thewhole volumemust be made cold; which is not the case with land.
A. 1st—Because thesurfaceof water isperpetually changing, and as fast asonesurface is made cold,anotheris presented: and
2ndly—The moment water is made coldit sinks, andwarmer portions of water rise to occupy its place: therefore, before thesurface of water is cooled, thewhole volumemust be made cold; which is not the case with land.
Q.What is the cause of a “pea-soup”london fog?A. These fogs (which occur generally in the winter time) are occasioned thus:—Some current of air (being suddenlycooled)descends into the warm streets, preventing the rise of the smoke, andforcing it back in a masstowards the earth.
Q.What is the cause of a “pea-soup”london fog?
Q.What is the cause of a “pea-soup”london fog?
A. These fogs (which occur generally in the winter time) are occasioned thus:—Some current of air (being suddenlycooled)descends into the warm streets, preventing the rise of the smoke, andforcing it back in a masstowards the earth.
A. These fogs (which occur generally in the winter time) are occasioned thus:—Some current of air (being suddenlycooled)descends into the warm streets, preventing the rise of the smoke, andforcing it back in a masstowards the earth.
Q.Why are there notalways fogsevery night?A. Because the air will always hold in solution a certain quantity of vapour, (which varies according to its temperature): and when the air isnot saturated with vapour, it may be condensed without parting with it.
Q.Why are there notalways fogsevery night?
Q.Why are there notalways fogsevery night?
A. Because the air will always hold in solution a certain quantity of vapour, (which varies according to its temperature): and when the air isnot saturated with vapour, it may be condensed without parting with it.
A. Because the air will always hold in solution a certain quantity of vapour, (which varies according to its temperature): and when the air isnot saturated with vapour, it may be condensed without parting with it.
Q.Why are thereever fogsat night?A. If the air bepretty well saturated with vapourduring the day, as soon as its capacity for holding vapouris lessened by the cold night, it deposits some of the superabundant vapour in the form of dew or fog.
Q.Why are thereever fogsat night?
Q.Why are thereever fogsat night?
A. If the air bepretty well saturated with vapourduring the day, as soon as its capacity for holding vapouris lessened by the cold night, it deposits some of the superabundant vapour in the form of dew or fog.
A. If the air bepretty well saturated with vapourduring the day, as soon as its capacity for holding vapouris lessened by the cold night, it deposits some of the superabundant vapour in the form of dew or fog.
Q.Why is there veryoftena fog overmarshesandriversat night-time?A. The air of marshes is almostalways near saturation; and, therefore, theleast depression of temperature, will compel it to relinquish some part of its moisture in dew or fog.
Q.Why is there veryoftena fog overmarshesandriversat night-time?
Q.Why is there veryoftena fog overmarshesandriversat night-time?
A. The air of marshes is almostalways near saturation; and, therefore, theleast depression of temperature, will compel it to relinquish some part of its moisture in dew or fog.
A. The air of marshes is almostalways near saturation; and, therefore, theleast depression of temperature, will compel it to relinquish some part of its moisture in dew or fog.
Q.What is thedifferencebetweendewandrain?A. Indew, the condensation is madenear the earth’s surface:Inrain, the drops fallfrom a considerable height; but the cause of both isthe same, viz.—coldcondensing the vapour of the air, when it is near the point ofsaturation.
Q.What is thedifferencebetweendewandrain?
Q.What is thedifferencebetweendewandrain?
A. Indew, the condensation is madenear the earth’s surface:Inrain, the drops fallfrom a considerable height; but the cause of both isthe same, viz.—coldcondensing the vapour of the air, when it is near the point ofsaturation.
A. Indew, the condensation is madenear the earth’s surface:
Inrain, the drops fallfrom a considerable height; but the cause of both isthe same, viz.—coldcondensing the vapour of the air, when it is near the point ofsaturation.
Q.Why doesmistandfog vanishat sunrise?A. Because the condensed particles are againchanged into invisible vapour, by the heat of the sun.
Q.Why doesmistandfog vanishat sunrise?
Q.Why doesmistandfog vanishat sunrise?
A. Because the condensed particles are againchanged into invisible vapour, by the heat of the sun.
A. Because the condensed particles are againchanged into invisible vapour, by the heat of the sun.