The Valley Virginian. [volume] (Staunton, Va.) 1865-1895, 1882-05-04
The Northern Lights.
Philadelphia Press.l

lFnllduelpuld fTesS.1
II am sure that don't know said Profess
sor Sharpless, of Harvard College. the we'll
known astronomer, last evening to Press re-
porter when asked the cause of the northern
lights, that have recently appeared in such
splendor "Like rain storm, they come with
out apparent cause 1t has been noticed, how
ever, that they are more likely to occur in win
ter than in summer We know that they are
the result OF some disturbance among the cleo
trio currents in the regions above the earth's
atmosphere, but now we come to subject
about which little is known. The earth's at
mosphere extends up about one hundred miles,
but it is not known what substance exists
above that. call it substance, for it is some
form of matter These phenomena take place
at a height of 500 or 600 miles above the earth,
as has been determined by observations OF the
same streams of light by different persons at
different stations and mathematical calcula-
tons. The spectroscope seems to show the
presence at this height of a substance new to
science, and something that is not known TO
our atmosphere, but nothing more than that.
There are theories, of course, as to what this
, unknown substance is, but they are not well
established, and good chance is open for
some one to distinguish himself by a grand
! discovery. Just at present the spectroscope is
the only means OF finding out the matter, and
as it has not succeeded, no new discovery Is
likely to be made Immediately.
THE CAUSE OF AURoRAs.
"The theory which is now generally held by
inen of science rs to the real cause OF these
auroras Is that they}are In some way connected
with the sun spots When there are the most
spots there are the most aurOras. There are
more than the usual number OF spots on the
sun lust now, and. on the morning after the
brilliant display of Sunday night, examined
the sun and noticed over dozen on Its sur
face The proof OF this connection between
these two occurrences is that the maximum
number of sun spots and the auroral displays
come at the same time. The periods when
these maximum numbers of sun spots occur
are about eleven years apart, and at the time
of their occurrence in 1859 and 1870 1t was
noticeable that the lvrthern lights were I'M
usually bright. never saw srch L.;..iant
sight as that of Sunday night, however. The
periodcity Of the maximum number OF sun
spots being eleven years, and the last having
been in 1870, last year should have witnessed
the expected display. 1t was little late, but
there were several bright auroras in the last
part of the year in the fall and winter. The
time for the displays will last through this
year, l expect, and they will probably be more
FREQUENT than they have Oeen. For the first
halt of the periods which mark the occur
renee of the maximum number of sun spots
there is dimnution in their number, SO that
there were none at all to be seen in 1875 and
1876, and after that they began to increase
This, you see, would bring the time for the
greatest expected display up to the present.
by sun spots, whose occurrence IN greater
numbers have said correspondent with the
times of the most brilliant and frequent auro-
raj displays, mean the dark spots that are
seen on the suns surface, They are hOllows
and depressions in the surface and are due to
some change in the molten liquid substance.
The surface is continually changing and their
depressions are probably the result of some
upheaval caused by the gases within. They
don't cover a very big proportion OF the SUMS
surface, however. Some are as big as 100,-
600 mills across, but that is the exception, and
most of them are below 10000 miles in width
They come and disappear quite suddenly often
sometimes in half hour, and again they may
last tor two or three months. They gradually
grow smaller and decline, and their average
duration is about month. II is the general
coincidence, though, that proves the relation
between the maximum numbers of these spots
and the auroras. The years which witness
the most spots will have the most displays.
THE SUN SPOTS CONNECTED.
"There may be some connection between
these spots and the weather. Some have
thought that the years of their greatest num-
Der were more stormy than others, but l do
not consider this we'll established. The APP
pearance of the streamers all radiating from a
common centre, which was so noticeable Sun
day night, may, in CERTAIN sense, be called an
optical delusion. They are really parallel,
and the centre from which they seem to start
is really the direction in which they are point
ed. AS for the flashing of the lights, that is
probably the effect of the passage Of electric
currents but not so muchis known about that
Nor can we tell what causes the different col
ors to be seen. Much the same effect is to be
produced, however, by the passing Of an cleo
trio current through vacuum tube. These
displays are very apt to extend over the entire
surface of the globe lying in the same latitude,
and it has been noticed that they usually oc-
cur on the same night here and in Europe.
The cause is the same for all. They are not
to be seen in the Tropics, but Arctic travellers
speak of their frequency and brillancy, they
coming every night. This is accounted for
by the fact that the North Pole is near the
magnetic pole of the earth. Speaking of mag
netism, the sun spots which / have mentioned
have an effect on the magnetic needle, and it
has been noticed that during the period ofthier
occurrence in greatest number the needle is
most apt to deviate from its true direction. The
whole matter is one of electricity and magnet
ism. These brilliant displays may be
going on all day for what we know, but there
| is no way of telling. There is no reason to sup
pose that the sun would spoil them, only they
would be invisible. There is no telling whether
the next display will be brighter than the last,
or when it will come. This is all uncertain.
But the theory that the displays are caused by
the sun spots is, think, well established"