A Guide To The Scientific Knowledge Of Things Familiar - novelonlinefull.com
You’re read light novel A Guide To The Scientific Knowledge Of Things Familiar Part 11 online at NovelOnlineFull.com. Please use the follow button to get notification about the latest chapter next time when you visit NovelOnlineFull.com. Use F11 button to read novel in full-screen(PC only). Drop by anytime you want to read free – fast – latest novel. It’s great if you could leave a comment, share your opinion about the new chapters, new novel with others on the internet. We’ll do our best to bring you the finest, latest novel everyday. Enjoy
Q. _Why is a YELLOW FLAME brighter than a RED HOT COAL?_
A. Because _yellow rays_ always produce the greatest amount of _light_; though _red rays_ produce the greatest amount of _heat_.
Q. _Why is the LIGHT of a fire MORE INTENSE sometimes than at others?_
A. The _intensity_ of fire-light depends upon the _whiteness_ to which the carbon is reduced, by combustion. If the carbon be _white hot_, its _combustion is perfect_, and the light intense; if not, the light is obscured by _smoke_.
Q. _Why will not CINDERS BLAZE, as well as FRESH coals?_
A. The _flame_ of coals is made chiefly by _hydrogen gas_. As soon as this gas is consumed, the hot cinders produce only an _invisible_ gas, called carbonic acid.
Q. _Where does the hydrogen gas of a fire come from?_
A. The _fuel is decomposed_ (by combustion) into its simple elements, carbon and hydrogen gas. (see p. 33)
Q. _Why does not a FIRE BLAZE on a FROSTY NIGHT, so long as it does upon another night?_
A. The air (being very cold) _rushes to the fire so rapidly_, that the coals burn out _faster_, and the inflammable gas _is sooner consumed_.
Q. _Why does a FIRE burn CLEAREST on a FROSTY night?_
A. Because the volatile gases are quickly consumed; and the solid carbon _plentifully supplied with air_, to make it burn bright and intensely.
Q. _Why does a FIRE burn more intensely in WINTER than in SUMMER time?_
A. Because the air is _colder_ in winter, than in summer-time.
Q. _How does the COLDNESS of the air increase the HEAT of a fire?_
A. For two reasons: 1st--Because cold air being more _condensed_ than hot air, contains a greater _body_: and
2ndly--Cold air _rushes more quickly to the fire_, and supplies more _oxygen_.
Q. _Why does the SUN, shining on a FIRE, make it DULL, and often put it out?_
A. 1st--When the sun shines, the air is rarefied; and, therefore, _flows more slowly to the fire_.
2ndly--As the air is _rarefied_, even that which _reaches_ the fire, _affords less nourishment_.
Q. _Why does the air flow to the fire more TARDILY for being RAREFIED?_
A. The greater the _contrast_ (between the _external air_, and that _which has been heated by the fire_) the more _rapid_ will be the current of air towards that fire.
Q. _Why does rarefied air afford LESS NOURISHMENT to fire, than cold air?_
A. Because it is _spread out_, (like a piece of gold _beaten into leaf_); and as a square inch of gold _leaf_ will not contain so much gold as a square inch of _bullion_--so, a square inch of _rarefied_ air has less _body_, than a square inch of _cold air_.
Q. _Why does a FIRE burn more fiercely in the OPEN AIR?_
A. 1st--Because the _air out-of-doors_ is more _dense_, than the air in-doors: and
2ndly--Because air is _more freely supplied_ to a fire out-of-doors.
Q. _Why is the air out-of-doors more DENSE than that in-doors?_
A. Because the circulation is more free; and as soon as any portion has been _rarefied_, it instantly escapes, and is supplied by _colder currents_.
Q. _Why does not a FIRE burn so freely in a THAW, as in a FROST?_
A. During a thaw, the air is filled with _vapour_; and, both _moves too slowly_, and is _too much diluted_ to nourish the fire.
Q. _Why does a FIRE burn so fiercely in WINDY weather?_
A. In windy weather the _air is rapidly changed_, and affords plentiful nourishment to the fire.
Q. _Why do a pair of BELLOWS get a fire up?_
A. A pair of bellows, (like the wind), _drives the air more rapidly to the fire_; and the plentiful supply of oxygen soon makes the fire burn intensely.
Q. _Why is a CANDLE BLOWN OUT by the breath, and not made more intense, like a fire?_
A. As the flame of a candle is confined to a _very small wick_, it is _severed_ from it by the breath; and (being unsupported) _must go out_.
Q. _Why is a SMOULDERING WICK sometimes REKINDLED by blowing it?_
A. The breath carries the air to it with _great rapidity_; and the oxygen of the air kindles the _red hot wick_, as it kindles charred wood.
Q. _Why is not the red hot wick kindled by the air AROUND it, without BLOWING it?_
