The
typical, bright, yellowish-orange upper part of a flame is due to the heating
of unburned carbon particles.
The
temperature of the fire and the material being burned are the factors that determine
the color of the flame. The various colors of flames in a wood fire are due to
the different substances in the flames.
The
strong orange color of most wood flames results when sodium contained in the wood
is heated
The
temperature of wood flames is lower than that of candle flames, which colors the
wood flames orange, not yellow. If, however, some of the carbon particles in the
fire are very hot, the color will be yellow. The product of the burnt carbon,
when it has cooled, is black soot.
Since
fire needs oxygen to burn, and since the bottom of a candle flame does not get
much oxygen, it is the hottest spot in the flame and is blue in color.
The
flame cools and changes color as it moves away from the source of the flame, because
it is exposed to more oxygen. The temperature change causes the color of the flame
to change from blue, at the hottest, lower portion of the flame, to the typical,
bright, yellowish-orange or bright orange color with which most people are familiar.
Which shade of orange is seen at the upper portion of the flame, where the flame
is the coolest, depends upon the material being burned.
Electrical,
flammable liquids, ordinary combustibles, and metal comprise the four types of
fire.
In
a year, lightning will cause 10,000 fires in the United States alone.
More
than 5 percent of the land on Earth is burned by fire every year.
The
bark of the redwood tree is fireproof. Fires in redwood forests take place inside
the trees.
A
perfectly clean fire produces almost no smoke. Smoke simply means that a fire
is not burning properly and that bits of unburned material are escaping.
At
12,000 feet above sea level, there is barely enough oxygen in La Paz, Bolivia
to support combustion. The city is nearly fireproof.
Forest
fires move faster uphill than downhill.
Of
all the world's peoples, the only ones known not to use fire are the Andaman Islanders
and the Pygmies.
The
word "curfew" is derived from an old French word that means," cover
fire." In Europe during the Middle Ages, a curfew was a metal cone or shield
that was used to put out the hearth fire in the evening. The word "curfew"
came to mean the end of the day's activities.