Amador ledger. (Jackson, Amador County, Calif.) 1875-19??, 1907-12-06

menon. The Coming Ship. "A New
African Wax.-A Mushroom School.
-Simpli6ed First Aid-The Malaria
Fish Manganese Manure.
Two kinds of partial blindness due
to light are recognized by DIR. A.
Birch Hirschfeld = one caused by
luminous rays and the other by ultra
violet rays. Looking at the sun with
the naked eye Injuries the center of
the retina, often permanently, and
this is due to luminous rays, other
rays being nearly all sifted from sun
light by the atmosphere. The night
blindness of fatigued and iIl-nourish-
ed persons results from slow recovery
of the retinal nerves after exposure
to strong light. The electric arc,
electric spark, magnesium light and
mercury vapor lamp emit az large pro-
portion of ultra violet rays, and these
produce such effects as snow blind
ness, electric light blindness, lightn-
ing blindness, and erythropsia or
"seeing red'' The snow blindness
usually occurs in high attitudes,
where sunlight is rich in ultraviolet
rays. Smoke colored glasses give the
best protection against luminous
rays, but thickness of the glass is
more important than color as shield
from the ultraviolet rays. The eyes
of the weak nervous and ill-nourish-
ed especially need guarding from
intense light.
Exposure to radium for a month,
in Prof. Bordas' experiments, seems
to have changed light red corundum
to ruby red, violet to sapphire blue,
and blue to emerald green, while
white became topaz yellow. An ex-
pert pronounced the changed speci
mems genuine precious stones, the
ruby of large value, and the ruby and
sapphire appear to differ in no re-
spect from the natural gems.
Photography, or change of color in
light and restoration to original color
in darkness, has been found by
Marck waldt in a very few substances.
Of possible value in photography,
the discovery is especially interesting
as representing a possible direct CON
version of light waves into chemical
energy.
Electrical engineers foresee at least
one more stage in the evolution of
Atlantic liners. The steam turbine
is most efficient at high speed, while
the propeller slips without doing full
work when driven beyond a COM
paratively slow rate, and gearing
down is impracticable with the great
horsepower of large vessels. With
turbines like those of the Lusitania,
made large for rate of only $50 re-
volutions per minute, much steam
reaches. the condensers without giving
up its full energy. A suggestion
that is being worked out already is
the use of turbines to drive electric
generators, which would propel the
vessel through electric motors, and
it is believed that the gain in en-
ploying high speed turbines would
more than balance the loss in trans
forming mechanical energy into
electricity and back again. The re-
arrangement of machinery would
leave more room for cargo. 1t is pre-
dicted that the coming fast passenger
ship may be given a speed of thirty
knots by six tuI DO generators of 20,
600 horsepower each, one to be used
only in case of break down, with four
propellers each having six motors of
5000 horsepower, one to be kept in
reserve for instant use in emergency.
The motors could be reversed almost
instantaneously, while the navigation
officer would control the vessel direct
from the bridge instead of through
signals to the engineers.
A material for which not much use
has yet been found is the wax of
My1ica cordifolIa, shrub originally
planted in Cape Colony,'Jo bind drift
sands. The Cape berry, as the fruit is
known. is about as large as a pea.
and three bushels produce ten to
fourteen pounds of wax, which is now
valued in London at 1915 per ton.
The wax seems to be adapted for
making soap, and possibly for can
dies
A novel institution of Tarare.
France. is theological laboratory,
where expert judgment is pronounced