The record-union., 1895-05-25
THOSE BEAUTIFUL SOLAR HALOS.
Weather Observer ]. A. Barwick Ex-
plains Their Character.
They Are Quite Common in Colorado
What Professor Loomis Has to
Say of Them.

Weather Observer J. A. Barwiok OF this
city favors the REcoRD-UNIoN with the
following explanation of the rare (in this
State) and beautiful phenomenon" re-
Gently Witnessed in the heavens. Says
Mr.. Barwick:
AS great many inquiries have been
made in reference to the rare sight in this
vicinity, bright circle around the sun,
on wednesday, near noon, wish TO say
that they are of very frequent occurrence
in the East or any country where the
high cirrus clouds form, and almost al
ways precede an approaching storm.
These circles form around the moon, as
we'll as the sun, and they are then called
lunar halOs, while around the sun they
are known as solar halos.
The most beautiful, perfect and grand
ones | ever saw were in Denver, Col, on
q very cold day in December. the tenn
perature of the air being from 12o to l50
below zero. The sight was such grand
one that the whole population turned out
to view it. 1t lasted several hours, and
the daily papers had it illustrated and pub
lished several columns of explanations
in reference thereto. The display con-
sisted of several solar halos, parhelic
circle, sun-dogs, or mock suns (as many
as eight having been seen at one tlme),
and contact arches, the latter being half
circles appearing in the zenith OF the OBJ
server, the colors of which were more
brilliant if possible than the brightest
rainbow l ever saw.
A little side-show like the solar sight OF
Wednesday would scarcely be noted in
climate like Colorado. Prof. Elias Loomls
Of Yale, in his treatise on meteorOlogy,
gives the following description OF how
halo of 22o radius is formed, this being
the size of the one seen here last w Wednes-
day. The Professor says:
"Wheneyer halos are formed about the
sun the air is filled with fine prismatio
crystals Of ice, and these crystals occupy
every possible position with respect 10
the SUMS light. The halo Of 220 radius is
formed by the light of the sun shining
through these crystals OF ice. If the
suns light furnished only red rays, we
should have an illuminated surface, with
circular opening of 2lt' radius, OF
which the inner edge would be quite
light. If the sun furnished only violet
rays we should have similar violet sur
face, with circular opening Of 22t0
radius, and the intermediate colors would
furnish circles of intermediate dimen-
SlOns.
"Now, since the SUMS rays contain all
the colors of the spectrum, these differ
ent circles are formed simultaneously and
superposed. The red projecting on the
inner side is unmingled with any other
color, and is therefore pure; all the other
colors are more or less mingled, but in
unequal proportions, so that the outer
portion of the halo is nearly white.
''Such a halo may be formed in mid
summer, because at a moderate elevation
above the earth's surface the condensed
vapor of the air is frozen, even in the hot
test weather. The circle within the halo
is much darker than the space without,
because from no part of this circle can a
ray of the sun refracted by ice prisms
reach the eye of the observer.
1.-The production of halos may be eX-
permentally illustrated by crystallizing
some salt, like alum, upon glass plate
and then looking through the plate at the
sun or candle A few drops of q satu-
rated solution of alum spread over plate
of glass will soon cover it with layer OF
minute crystals. If we place the eye close
behind the smooth side of the glass and
look at q candle we shall see the candle
surrounded by three halos of different
dimensions. Each crystal of alum is a
regular octahedron, with the six angles
truncated. forming the outline of cube
1t has, therefore, faces inclined to each
other at angles of 7O0, go and 1l0', and
those angles occupy every possible posi-
ton with respect to the glass plate.
1.-THE smallest halo is formed by the re-
traction OF tne rays OF HRnt through
pair Of faces inclined to each other at an
angle of 700; the second halo is formed by
a pair of faces inclined to each other 900,
and the third halo by faces inclined to
each other at an angle of 1l00."
The above are quotations from Profess
sor Loomis, and give both the cause of
the recent solar sight and how it can be
produced artificially. When one appears
again in the heavens above US there need
be no great amount of oommotion or
wonderment.