Evening star. [volume] (Washington, D.C.) 1854-1972, 1911-02-12

through a cake OF ice WITHOUT IlelllllS lHe
ice particle. 1t was done by interpreting a
transparent tank of water between the lens
and the ice: the water taking all the heat
capable of affecting water or ice and becom-
ing hot itself, while the ice remained undis-
turbed. Yet gunpowder may be exploded
by means of the rays transmitted through
ice.
Nearly all heat from the sun will pass
through glass; but it has been found that
from white hot platinum the glass absorbs
one-fourth of its total heat. The most as
founding experiment was made with copper
heated to whiteness 1t was found that the
glass through which it tried to go absorbed
nineteen-twentieths, allowing only one-twen-
tieth to go through.
As is well known, heat from the sun comes
through glass with facility into room, and
heats up objects in the room. The objects
change this heat to dark rays, and it cannot
get out again. If glass transmitted major
ity of the heat waves from a not stove, we
should most certainly have to have winter
rooms without windows, or else lose all our
heat. Along the same lines is the method of
the earth in retaining the heat of the sun
through the night. The atmosphere allows
almost all the suns heat to pass through to
the earth; but there the waves are changed
and cannot get out.
A possibility of some interest is pointed
out by Warren. 1t is that some planets that
do not receive so much heat as the earth
NAV have different kind of atmosphere
which keeps in more heat than does ours,
and therefore can have as great a tempera-
ture as ours. If we kept all the heat the sun
gives us, we could not live on this planet;
for the amount would accumulate day by day
until it became unbearable. The planet
Mars is notable instance. 1t receives only
about one thousandth the heat the earth re-
ceives; but observations go to show that its
temperature is as high as ours.
Laurence Hodges
Mock Suns
THESE are similar in point of origin to the
mirages of the desert, only they occur in
the Arctic circle. As the long winter night of
the polar region wanes, once every twenty
four hours a slight glow is seen at some point
on the horizon. Often accompanying this
glow is seen the phenomenon OF the mock
suns. Several degrees up in the heavens as
many as five of these spectral Orbs have been
seen at one time. Invariably they are all
connected in a geometrlc figure, the suns
seemingly bound together with circles and
arcs of light.
Often when only one appears it is mistaken
for the real god of day, and natives rejoice at
the early end of the long winter night, only
to be disappointed as the image disappears.
The explanation of the phenomenon is
given by physicists as refraction and ref1ec-
ton of light from the real sun below the hori-
zon on the mists in the upper atmosphere.
Curious Transference of Heat
A WORKMAN in the observatory at Tou-
louise has invited attention to singular
phenomenon. bar of iron is taken by the
end and the other end is plunged into fire.
heating it strongly, but not SO much that the
hand cannot retain its hold. the heated end
is then plunged into pail of cold water I'M
mediately the other end becomes SO hot that
it is impossible to hold it. This phenome-
non, familiar to workmen in iron, is ascribed
by them to some repellent action they sup
pose the sudden cold exerts upon the heat
contained in the iron, which is thus driven to
the opposite extremity.