The Baltimore County union., 1886-11-06
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
SPANISH GEOGRAPHY.

SPANISH GEOGRAPHY.
The field for geographical exploration is not
yet exhausted even in Europe. Schroeder states
that in the north of Spain several ranges of noun
tains exist, some reaching height of 900 feet
which have no place on any geographical map.
In the Aran valley another discovery has recently
been made. Triangulation showed gap untitled
between two chains of peaks which, approached
from different sides, had been supposed to form a
single range; and further exploration proved
that the gap contained large and hitherto un-
known lake.
VALUABLE QUARTZ.
A'favorite form of manufacturing quartz crys
tails is tho sphere, and balls of three inches or
more in diameter are very valuable on account of
the rarity of large masses OF perfectly clear stone
One of the largest and most perfect balls OF crys
tai known is 500 inches in diameter, and is now
in Dresden. The finest ball in this country is
owned BY Mr.. r. e. Moore, measures 6.625 inches,
and is valued at $500. So the large
pieces of fine quartz that one dealer is said to
keep a standing offer of 81 600 for material for
fve-inch ball, ST. 500 for one of five and a halt
inches, and 81, 900 for a seven inch ball.
RAILWAY EXPANSION.
In climates having difference of seventy de-
grees in temperature between the hot and cold
seasons, railway track of 400 miles is 33S yards
longer in summer than in winter. OF course the
length of road remains the same, but expansion
forces the lengths of metal closer together making
aggregate
rails of nearly yard in each mile
LAND ELEVATION.
Dana finds that the average height OF the land
above sea- level is about 900 feet, and that this
would probably cover the bottom of the sea to the
depth of 375 feet that, taking the average
depth at 16 600 feet, it would take forty times as
much land as exists above sea- level to fiji the
oceanic depressions The mean height of Europe
has been stated to be $40 feet (Leitpodt makes it
974 feet) ASIA 1,150; Europe and Asia together,
10l0 North America, 74S; South America,
1l32 all America, $50 Africa, probably about
1000 feet; and Australia, perhaps 500. So far
as now known, the extremes of level in the land
are 1000 feet ADORE the level of the ocean, in
Noun, Everest of the Himaayas, and 1900 feet
6elo,o it, at the Dead Sea. Asia has also a great
depressed Caspian area; Africa, in the Algerian
'chotts' sinks to 100 feet below level while
in America, Deaths Valley, California, reaches
from 100 to 200 feet lower than the ocean sur
face.
SOIL, CROPS AND MOISTURE.
The interesting researches in Germany of Prof.
E. Wollny have shown that both soil and crops
have great influence upon the proportion OF
moisture in the atmospheric. Other things being
euual the atmospheric moisture is greatest
over humus soils, least over sands, and takes an
intermediate position clays. The air over
fiat and concave surfaces is moister than that
over adjacent slopes. Ground inclining to the
north contributes more to the moisture OF the air
than southern slopes, while easterly and westerly
inclines take an intermediate place. The mois-
ture is greater over plcnt-covered tract than
over bare SOIL and increases with the density of
the vegetation. Among ordinary crops, meadows
impart most moisture to the air; then follow
perennial fodder plants, such as clover and lucern;
then summer crops which have prolonged vege-
tation, such as turnips, maize, oats, beans and
potatoes then those of briefer growth, as TAX
rye, barley and peas; and, lastly, winter wheat.
COURAGE IN DISEASE
Considering tEep siologicaJ effects of courage,
prominent medical authority concludes that,
contrary to a common notion, no effort of the will
can check the development of hydrophohia-
Courage is powerful and not entirely understood
remedial agent, but it cannot prevail against
germ disease that directly attacks the Immediate
vicinity of the vital centres. the mere pin prick
ing of which inevitably terminates in death.
THE SEVEN STARS.
An interesting test of visual power may be
found in the Pleades commonly called "the seven
stars" Ordinarily only six stars are visible to
the naked eye, although the telescope shows
large number of smaller ones IN the group. But
nearly thirty years before the discovery OF the
telescope Moestlin mapped eleven stars and may
have observed fourteen while Prof. w. f. Den
ming, the we'll known English astronomer, claims
that be can usually discern thirteen of the stars
with the naked eye, and on one occasion was able
to see the fourteenth.
MISCELLANEOUS.
The discovery of new gutta percha tree Is
reported from East Nicaragua, the milk of the
"tuno" being said to furnish gutta -percha of
superior quality. The supply is stated to be
practically inexhaustihle
At the Vesuvian Observatory, Palmierl has
found that when steam is condensed by cold, mega
tive electricity is developed, but that positive
electricity is produced during evaporation.
The Swedish Academy of Sciences is about to
establish, near Stockholm, botanic garden like
the famous Kew Gardens in England.
The advantage of country life to physical de-
velopment is shown by Galton, who has found
- that English country boys of fourteen years
average an inch and quarter more in height,
and seven pounds more in weight, than city
boys Of the same age. -..l
The great rejecting telescope at Melbourn Is
devoted chiefly to the observation of nebulae.-
With it have been discovered indications of great
changes in some of these celestial bodies during
the last few y ears, such changes being sought to
confirm the generally acce ted nebular theory of
tha 0in of the solar stem. y y