Mexico weekly ledger., 1884-12-11
THE NORTHERN LIGHTS.
a Look at the Mystery of the Northern
Lights or Aurora Borealis.

bt1C N0n nCnN 16t D
a Look at the Mystery of the Northern
Lights or Aurora Borealis.
These appearances are most gener-
ally known as the Northern lights, the
merry dancers, or the Aurora Borealis,,
owing to the fact that the Northern lat
itudes have been much more visited
than the Southern. The same phenom-
ena, however, are to be seen as we go
southwark, and so they are sometimes
spoken of under the name of Aurora,
Australia. We have chosen the most
popular name for our title. though,
perhaps the most appropriate one that
has been applied to them is that of
Aurora Polaria. As few of those who
read this will ever have the emporium
ity of actually visiting either the North,
ern or Southern Polar regions, let us
imagine ourselves for a brief season tt
be upon the deck of a vessel far away
in the North-let us say in the autumn.
just before the approach of the long
Arctic night. As we glance round, all
looks cold and bleak. There is light.
enough for us to see on every hand the
fantastic forms of the icebergs looming
up in the darkness. We hear the grind
ing of the bergs together, and cannot
suppress an uncomfortable feeling as
the contingency presents itself in our
mind of the ship getting aground be-
tween two of those huge floating
ice islands. As we look. the scene
changes as completely as though a.
magician's wand had transferred us to
one of the ieweled palaces of the
arabian Nights" We see arches of
light stretching across the heavensf from
east to west-sometimes remaining sta
~tionary, and sometimes moving slowly,
towards the south. Rays of light shoot.
out perpendicularly from the arches,
and if the arches are below the horizon
we only see these rays, which, though
nearly parallel, often appear as an eff
feet of perspective to meet in q pointin
the zenith. These rays very seldom
remain stationary, but shoot upwards
towards the zenith, at the same time
moving eastward, often with a tremu-
lous, snake-like motion from end
to end, till sometimes they cover the
whole sky. Ii now we turn II eyes,
from this magnificent light to look
upon the surrounding mass of bergs,
which Just now looked so weird and.
gloomy, we can scarcely believe that
they are the same, for now they throw
back to us, in a thousand colors, the.
light that flashes on them from above,
and the peaks and ~pinnacles of the.
bergs appear to be set with jewels of
the most varied hues and the most daz-
zling brightness. The rays appear in
the most varied forms and patterns, in
one of the most beautiful of which,
though seldom seen, the rays appear to
hang from the sky in folds like a man
tie. 1t is at present rather doubtful
whether the auroral displays are or are
, not accompanied by any sound.
{ Many observers have asserted that dur
!, ing an aurora, they have heard crack
, ling and kissing sounds: and some ok
periments made by NJ. Plante, as they
: throw great light on the theory of the
. aurora decidedly support this view. On
2 the other hand. some of the most emf
5 nent polar explorers have listened in
4 vain for these sounds. and have given
G it as their opinion that what was heard
D was merely the breaking up of the ice
b and the grinding of the icebergs. Hav.
ing now in our mind the appearance OF
l these Northern lights, we will repeat
| well-known laboratory experiment
l We take. a glass cylinder, covered al
the end with brass caps, n of which i:
I fitted with a stop-cock, which we cal
screw to the plate of an air pump. IL
the brass caps we now attach thu
terminals of a powerful induction coil
but as yet we perceive no result. w
: now begin to exhaust the air from th'
G cylinder, and as the exhaustion goes w
e soon see a soft, tremulous light begin
ming to play about the ends of TIL
n cylinder, and this, when the air is suffi
e GENTLY rarified, gradually extend
5 through the cylinder. As we %continu
d the exhaustion, these phenomena will
It be reversed, the light gradually dyin:
s away as the exhaustion increases. W,
n shall at onc perceive how very mucl
d this resembles an aurora on Il small
k scale. and so we have electricity sue
e gested to us as the agent which pro
q duces the aurora.-Science for All.