The semi-weekly messenger. [volume] (Wilmington, N.C.) 1897-1908, 1906-02-16
NATURE STUDY OUTLINE

For week beginning February 18th
For Sixth Grade.
The heat of the N causes con-
slant evaporation from the surface OF
all water exposed to its rays. The
amount Of water thus quietly thrown
into the atmosphere is enormous. To
demonstrate by a few simple observa-
ions the presence OF moisture in the
air viii be- an interesting exercise,
and VIII open the way 10 a clearer un-
Outstanding OF the phenomena OF frost,
dew. and cloud formation.
Place a pitcher or lumber Of cold
water in a warm room. What hap
pens? The pupils will say that the
pitcher or glass "sweats." Where is
this moisture formed: Where has ii
come from? Compare The temperature
Of the glass with that OF the atmos-
phere. What effect had contact with
the cold vessel on the vapor OF thea at
mosphere? How then is the condi-
| ton OF invisible vapor affected by its
| contact with Il body OF lower tenn
perature. Introduce here the words
"~condense" and condensation. I'm
der what circumstances then is vapor
.'condensed"
Breathe against a cold slate. What
happens? Why is the breath visible
on a cold morning. Why is it not
visible ON a warm morning: Explain
why windows i'll cold weather are
clousiei with moisture On which side
| Of the window is the moisture form
ed: Why? What becomes of all OF
the yapor constantly forming on the
earth. Under what condition is the
Invisible vapor of the air condensed?
after the sun goes down the accu-
mulated heat Of the day is given back
from the earth into the air. Thus the
surface is often cooled very rapidly.
This is particularly true Of blades OF
grass because of their greatly exposed
! surface. They become cold much
more rapidly than the surrounding at
mosphere and Oh them is condensed
water vapor in the form of dew.
Observe the grass upon successive
mornings. Neal water. away from
water. Does the amount of dew vary
with the conditions of atmosphere: is
| it present during the day: When does
it disappearE
Is dew formed in greater abundance
during a clear or cloudy night? In a
calm or a windy night? Anything
that VIII keep Il surface from adiat-
ing heat will keep that surface free
from dew. Clouds prevent rapid a
alton Of head. Therefore dew is not
formed on Il cloudy night.
During what time Of the year Is dew
found? If the temperature of the air
were very low, below the freezing
point Of water, what would become
Of the dew as it formed? When wa
ter vapOr at the surface of the earth
freezes as it ~condenses it is called
hoar-froSt. Under what conditions is
frost formed? Is frost formed on a
clear or a cloury night? On a windy
or a quiet night? Make perfectly
clear or a cloudy night: On a windy
vapor condensed as il solid and is
therefore to be compared with snow
not with hail Or vapor frozen after
condensation Ia taken place.
When vapor is condensed and floats
very near the surface of the earth it
is called fog or mist. In what locali-
ties is fog formed? At what time of
the day are we most likely to have
fog in these localities? What vas the
condition of the atmosphere? When
and why did the fog disappear? When
and where are other such t1eecy forms
of vapOr found? Observe h move
ment In appearance of the clouds.
What is the cause of their movement?
Try to distinguish the particular type
of clouds. The following are the most
common forms:
1. Feather clouds (circus), those
clouds that are high above us and are
light and feathery. They may be
white or blush.
,. Great rolling cloud masses
(cumuluS) clouds that resemble great
packs of wool or the appearance Of
mountains piled high upon n an
other.
8 Layer clouds (stratus) those
clouds that are seen most frequently
in the morning in layers one above
another or in layers side by side.
There are a number of charming
cloud myths or stories which could be
read or told in this connection. The
Swan Maidens' in Cookies Myths is
delightful. Also story of Pegasus
and Bellerophon" a. told by Haw-
thorne in his Wonder Book would add
much to this cloud study.
MRS. +. L. STEVENS.