Omaha daily bee., 1916-07-15
WOndfrS of
the Mirage
By GARRETT P. SERVISS.

Can anything that happens on earth
be reflected in the sky? My grandfather
tells a story Of a battle fought between
Germany and France about nifty years ago.
seen In the sky In Poland at the same time.
Is this fiction or factl
1t may be partly fact and partly
imagination. If l knew all the de-
tails l might be able to tell you how
much of the story could be scienti-
fically explained and how much
should be set down to vivid fancy.
1t is possible that what your grand
father, or his informants, saw was a
mirage, one of the most wonderful
of natural phenomena. A mirage is
an apparition in the atmosphere arising
from an extraordinary reffaction
(bending) of rays Of light by the air.
The refractingN power of air varies
with its density, and in some cases
it causes objects lying behind and
below the horizon to appear as if
they were suspended in the sky above
the horizon, and when, as OCCASION
ally happens, magnifying effect is
produced the objects even appear to
be nearer than the horizon.
If you look through a pane OF
glass full of veins and inequalities
you will see what surprising effects
irregular refraction of light is capable
of producing Although recall no
case in which the scenes of a battle
have been pictured in the sky, yet
such thing might, theoretically,
happen. But itis practically impos-
sible that il should occur when the
distance between the observer and
the actual scene is so great as the 500
miles~separating the western border
of Poland from the nearest point in
France where any battle was fought
in the war of 1870
The greatest distance involved in
any authenticated account of a mir
age with which l am acquainted was
fifty miles. This mirage was seen
on the coast Of Surrey, England, on
the afternoon of July, rs, 1898, the
chief observer being Mr.. Latham, a
fellow of the Royal Society.
From Hastings he plainly saw the
cliffs on the shore of France, fifty
miles away in an airline, and in Or
binary circumstances totally invisible
on account of the rotundity of the
earth. In fact, at a distance of fifty
miles the surface of the globe rounds
off or falls below the level of the
observers eye more than 1000 feet.
Yet on this occasion not only was
the French coast lifted up into view
by refraction, but there was also,
apparently, a magnfying effect, since
it seemed to be only a few miles
away.
Some sailors who were with Mr..
Latham poited out to him the de-
tails of the French coast which were
familiar to them from their visits
to it, and with telescope French
fishing boats could be seen at an
Choir, while the buildings on the
shore and the colors of the vegeta-
ton were plainly discerned.
These appearances continued for
nearly an hour, the cliffs sometimes
appearing brighter and nearer, and
at other times fainter and more re-
mote.
In another authenticated instance
troops of cavalry exercising on tho
farther side of a hill range were
seen as if they were on the hither
side of the hill. In this case the
actual difference between the obser-
vers and the objects was about
dozen miles. On yet another oc-
casion. Prof. Vince of Cam
bridge saw Dover Castle apparently
lifted over hill, which conceals it
from the point of view where his
observation was made, and projected
against the side of the hill facing
him.
These wonderful appearances can
all be explained by the effects of If
regular atmospheric refraction. But,
now let US take the case of the ap-
partition in Poland, supposing the
story to be based upon mirage.
While at distance of fifty miles
the depression below the level OF
the true horizon is only about 1000
feet, at distance of 500 miles it is
a hundred times as great, or about
80 miles, the depression varying as
the square of the distance.
1t is not conceivable that in so
vast an extent of air as would ba
involved in this case the effects Of
refraction could produce a mirage
bringing into view objects 500 miles
away and sunk 80 miles below the
horizon.
What may have happened was 4
mirage, similar to that above men,
toned, in which troops moving be-
hind some hill or elevation of the
ground were brought into view, ap-
pearing, in this case, not against the
intervening elevation, but above it in
the sky. Many effects of this kind
are on record.
At this time of which your grand
father speaks, all Germany was astir
with military movements, and if tho
point of observation was situated
near the German frontier we have tho
proper setting for possible mirage
of the kind described. Naturally the
observers, having their minds full
OF the war, and seeing the appari-
ton above the western horizon,
would imagine that they were view.
ing a battle in France, miraculously
reflected in the sky, and the more so
if clouds of dust or smoke from ac-
tua1 firing enve1oned the aar;,I ,o.,