The Washington herald., 1911-05-07

@EAr ia the great life giving power. At
H lccet, without heat there would be
It'll universal death. There would be no
HK dew, no circulation OF air, no npe
Ve fruits. no change Of seasons, but win
ter in its severest form. Ice is water
without heat Water is ice with heat addeo
to IT, Steam is ice with more heat added TO
it. Happily for us, ice is lighter than WAFER
This is contrary to the general rule, namely,
that as bodies get colder they get heavier.
Il is fortunate that ice does not sink. For
IL it did the sea and river bottoms would De
a mass oil il, and our climate would be ike
that in the polar circle.
Other solids rs well as ice become liquid oy
having heat applied to them. The metals, all
OF them, can be melted by means OF heat ;
one of them, that is quicksilver, being always
liquid until exposed TO very severe cold, when
it becomes solid and heavier than it was.
II you plunge frozen quicksilver into warm
water it melts quickly by taking away the
heat from the water, SO quickly, indeed, that
the water becomes a lump OF ice.
Some metals do not liqulfy unless a great
heat is applied to them. Gold requires the
heat of 1900 degrees. We all know, also,
instance, water into steam. If this were not
90, that s, if the suns heat could not raise
up, in the form OF vapor, the water in the
earth and sea, we should have no dew nor
rain, which are merely vapor 80 cooled as once
more to regain the shape OF water. Many
millions OF gallons are raised every hour from
the sea, then formed into clouds and carried
about by the wind.
In our world there are constant changes,
but nothing can ever cease to be. you Durn
wood, straw or paper in a furnace. 1t soon
becomes ashes, but it has not been destroyed
The materials OF which the wood or paper
were made have been changed into gases and
vapors, an6 are flying about the air, to be
inhaled by the plants.
All things are expanded by heat; the greater
the heat. the greater the expansion: As in
the thermometer, if you thrust it into hot
water, or expose it to the sun, the quicksil-
yer is seen to rise in the tube. This is be-
cause the heat applied to the bulb, as it is
called, causes the mercury to swell or ex-
pand, and as the glass prevents 1t from ex-
panding in all directions, as it would if it
could, the liquid metal is forced upwards,
where it Is not restrained On the side OF
=, thermometer is a scale OF degrees. Thirty
two is the point where water freezes, that is,
when water freezes the mercury is level with
that particular point. Sea water, however,
does not freeze until it is about four degrees
colder.
When water boils the quicksilver rises to
R12 degrees. 1t boils at that point, but you
cannot make it hotter, for when it passes that
point it ceases to be water; it becomes steam.
Water bois at 212, but spirits Of wine boil
while mercury itself does not boil till you get
. heat more than three times az great as that
ut which wRter b0ils. Heated bodies give out
their heat tG other bodies. This is why the
lire warns us and cooks our food. The heat
goes out in straight lines and in all directions,
but particularly above the heated body. Hence
much heat from fire is lost, tor the hottest
particles go straight up the chimney.
We have said there would be no dew if