Jamestown weekly alert. [volume] (Jamestown, Stutsman County, D.T. [N.D.]) 1882-1925, 1915-03-25
MARCH A MONTH OF
AURORAL DISPLAYS
Source Of the Northern Lights
Subtleties of Electricity.

Source OF the Northern Lights
Subtleties of Electricity.
) There was a fine auroral arc dis
played in the northern heavens one
night recently, extending from hori-
zon to horizon with the summit of the
arc high in the heavens. The under
edge was clearly defined and the sky
seemed much darker beneath than
above and starlight could be seen
through this dark portion. 1t is a
question among astronomers wheth-
.er this darker portion is an atmos-
pheric effect or merely an appear
ance.
Auroras in this latitude become
quite frequent in March and October.
here are few data regarding the
aurora australis, as it is called for
the southern hemisphere, as there
are no high bodies of land inhabit-
ed in the far south in that hemis-
phere. ...
The aurora borealis of the north
ern hemisphere has 'been long OBJ
served and carefully studied. From
the equator going north it is found
that the average number of auroras
visible in southern Spain is only one
in ten years; in northern France the
average is five a year; in Ireland,
thirty; Shetland Islands, 100; and
between the Shetland Islands and
Iceland is the maximum. In south7
ern Canada and the United States
they are seen more frequently than
In the same latitudes Of Europe.
.Auroras vary in number during
the months of the year. At Ham
merfest, Norway, the most l,ortherly
town in the world, in north latitude
7Ok, the number Of auroras during
January and December will average
20. During the four midsummer
months there are none visible. In
middle latitudes this variation is less
and more auroras are seen in mid
summer.
Auroras exist without doubt when
the sun is shining, the same as when
lit is not, but are less visible in day
IliRht, and in the high northern lati-
tudes the absence of the sun below
the horizon in the midwinter months
lis the cause of the greater number OF
auroras being seen, In midsummer,
when the SUM- does not 60 below the
horizon, there are no auroras visible
lin certain localities. Clouds and
moonlight also weaken the bright
ness of auroras and in the high
northern latitudes the aurora often
takes the place of moonlight.
Astronomers find that auroras cor
respond with or have a peculiar con-
nection with sun spot periods, which
appear to affect both the intensity
and frequency of the auroras, indi-
eating that the origin of our, north
ern lights is the great gaseous fur
mace of the sun, the source of light,
heat and power for this earth and the
inhabitants thereof. There is also a
known connection between the auro-
ras and magnetic earth storms regis
tered in temperate latitudes. A
bright aurora visible over a large
part of Europe is accompanied by
magnetic storms and disturbed earth
currents. The brilliant changes OF
color are most attractive phases OF
the aurora from spectacular point
of view and the auroral curtain with
it's shifting colors travelling across
the northern skies with great velocity
is a magnificent spectacle. During
Isuch times the needle in the compass
is visibly affected in high latitudes
and the passing of an aurora across
the upper skies will affect the needle
lin the same way as if an electric cur
rent was directed upwards from the
ground.
The light of the aurora varies
greatly in intensity. At Jan Mayen
land, an island in the Arctic ocean,
800 miles east of Greenland in north
latitude II, the auroral lights at
times are so brilliant as to make the
full moon look like an ordinary gas
let. The arcs are always brighter
at the lower parts than the SUBMITS
The colors are ordinarily white with
green and red tints. Many years
ago the famous deep red aurora
that spread over the entire northern
sky far beyond the zenith and con-
|tinued during the whole night is still
Remembered by many observers IN
North Dakota.
The spectroscope shows lines in ar
|aurora, indicating hydrogen, oxygen
and nitrogen. and there is one line