The morning news. [volume] (Savannah, Ga.) 1887-1900, 1892-07-24

ago II has been seen by a good many others
since then. Mr.. Blake was down there as
geologist for the party Of Exploration and
surveys for the Pacific railroad" Dr. j. Il.
Cooper of the Academy Of Sciepc in this
city was one Of his number. Mr.. Blake Is
at present professor in the scientific de.
partment Of Yale College. He explained
the mirage in this way:
cater reaching Fort Yuma ninety miles
distant from Carrie creek, and witnessing
the strangely precipitous and pinnacled out
line OF the mountains beyond 1t was at
once apparent the mirage consisted OF their
distorted images. When in the northern
part OF the desert we often saw tue peak of
Signal mountain, distorted and raised above
the horrIson. Points Of distant ranges
seemed to be elevated above the surf ace
precisely as headlands Of coast sometimes
appear to rise above the water at sea.
MANY OF the phenomena called mirage
are not due 10 fetraetion, bat are believed
TO be the result OF reflection from smooth
surfaces of clay or sand.
THE beautiful surface Of a pebbly plain
may be regarded as Il combination of myr-
lads OF re6ectors, for each highly polished
pebble reflects light almost like a looking
glass. The reflection from such brilliant
surfaee, when seen at a favorable angle,
looks like a sheet of water, the similarity
being heightened by the motion Of the
stratum OF heat and air"
The last clause may be taken as an ex-
PLANTATION Of the distorted mountain mirage
which Mr.. Blake described. but did not dis
sect
The motion of the stratum Of heated air
has the effect of enlarging distant objects,
bringing those beyoud the focus of the
eye into clear vision. That kind Of air
taken in connection with rays of light, may
assume fantastical shades and colors
On the Mojave desert and through the
San Joaquin valley from Fresno 70 Bakers
field, a mirage showing depressed or ell
evated appearance OF the ground is COM
mon. 1t may be seen at most any place
along the line on either side or the railroad.
The distortion of objects at this time Is no
ticeable. You can see farm houses plainly
that are usually not visible. Streets of a
town that is In the dim distance are in plain
sight. Everything comes TO you as II You
were looking through field glass and en-
larged as IL under microscope
The ground becomes very heated IN this
valley during the day. II coois off cons
siderably during the night. There is a
vibratory motion of air caused by radiation
when the sun again strikes the earth. That
is the explanation.
Now, in the evening in the San Joaquin
the picture is turned. Instead of depres-
sion you notice an elevation OF the ground.
1t goes up from you instead OF going do wn.
Otherwise the picture is about tbe same.
The difference is due to the condition Of the
ground. The surface is heating in the
morning and cooling in the evening. These
same conditions are sometimes tonnd In the
Sacramento valley. A mirage answering
this description that is quite persistent there
is at point about forty miles south of
SACRAMENTO, looking east from the Central
Pacific railrord.
East, but not least, is one at Santa Bar
barA. The best view of it is from the hill
at the old mission, looking toward the
town which seems to be in the air Look
ing over the town and out to sea, you will
see we'll trimmed vessels moving like air
ships far above your head, and the cliffs Of
the Santa Cruz Island, thirty miles away,
are from you stones throw