The Mankato free press. [volume] (Mankato, Blue Earth County, Minn.) 1879-1924, 1902-01-03
ABOUT SUN RINGS.
Queer Things the Astronomers See;
Through the BIG telescopes.

In regard to the halo around the sun
which created much excitement
throughout the eastern section or this
country, Mr.. Jutsice Stain, secretary
of the astronomical section OF the
Maryland Academy of Science, says
every often, when the heavens are
overcast by slight, or light, feecy
clouds, we observe .colored rings about
the moon and the sun. They are
termed halos, or aureoles. L have
never observed a halo about the sun in
the latitude of Baltimore, but halos
about the moon are quite frequent.
One of the most brilliant that L have
observed in Baltimore occur req some
time in the beginning OF l9Ol. very
often he halos do not form a complete
circle, but are visible only In sections.
Probably the reason we DO not notlce
the halo about the sun is on account
of its intense brilliancy, and that we
do not look at it directly. The best
way to observe halos is to observe the
reflection of the sun in a black mir
ror, black glass or glass smoked on one
side. In meteorology the halos are d.
vided into two classes-the corona,
| which is of small diameter, and the
halo, which is of greater extent. In
| the corona the color of the inner part
of the ring is blue, and the outer red
In the large halo the red is on the In
side and the blue outside. The corona
is classed as a different phenomena
that is, the light from the sun or moon
is encountering the small particles in
the cloud or which form the cloud Is
broken up, scattered or diffracted, like
the graftings that Prof. Rawland ruled
at the Johns Hopkins university.
Diffracted light may be of two kinds.
1t may pass through fine material and
be diffracted like in transmlssl on
grating, or it may be broken up by
encountering the fine particles and be-
ing reflected. We never have dltfrac.
tion caused by reflection of the light
from the small particles in the cloud.
1 The halo is supposed to be due both te
diffraction and reflection. When light
is diffracted it passes through
medium which both disperses it and
bends it out of it's course. Thus the
rainbow is produced by the sunlight
passing through the drops of water an(
the water regional ways opposite t.
the sun. Halos occur only in the
higher clouds and are more frequen
than the corona. Sometimes the halo
intersect each other, and at their In
tersection round patches are formed
called mock suns The particles O.
matter forming the medium for re
fracting the light are mostly small ic
crystals or ice needles. Mr.. Glider
sleeve, the late president of the Balti
more Astronomical society, related tina
at various times he had observed snow
storms through the telescope while
making daylight observations of tn
stars and planets. At any rate there i
considerable solid matter in the at
, mosphere that we sometimes observ
, in sweeping around with the tele
scope. On rare occasions we can see
bird flying across he field OF view, o
which not sign can be seen with tn
J naked eye. Then, again, small speck
F fly across, looking like small meteors
At one time I observed ray seemin
to have it's origin at the setting su
on the horizon and extending as
3 slender beam clear to the zenith an
, lost to view little to the east OF tn
zenith The mock suns are mostly see
in high ATTITUDES. We can then com
to the conclusion that halos and moe
e suns are simply due to the state of tn
atmosphere when it contains moisture
ice crystals and snow, and they exis
ed from the remotest times, when til
earth had been fashioned to its preseI
9 condition, and there is no cause IL
n alarm. baltimore News.