The Stark County Democrat. [volume] (Canton, Ohio) 1833-1912, 1900-06-08
SCIENTIFIC
MISCELLANY.
Swimming Magnets-.-Fish De-
ceptiOn.-.A French Want.
THE PROBLEM OF FLIGHT.

Economical Separation of Sea Water Gold
-Uniform Time by Electric Waves
The New Brick-NIaking-A Re-
markabie Cement.
Magnetic attraction and repulsion are
illustrated in a very interesting manner
in new experiment devised by Prof.
s. p. Thompson. A circular coil of wire
is placed with it's axis horizontal in a
tank of water, and a number of small
bar magnets sealed into glass tubes are
also dropped into the tank. The weight
Of the tubes is so adjusted that some
Just float while others just sink. When
current Is passed through the wire
the magnets are attracted and sucked
into the coil, and IL the current is sud-
denly cut off and reversed as they are
approaching, they are repelled and turn
back. BY careful manipulation the
tubes seem simply to dart at and
through the coil.
So great is the sensibility of the leech
Clepsine that the creature is disturbed
by the touch of needle point on the
surface of the water of its containing
vessel. There is reason to believe that
fishes also quickly detect disturbances
in the water, but DR.. r. w. Shufeldt
thinks the peculiar sensitiveness to
teasing of the snowy grouper (Epine-
phelus niveatus), requires special ex-
planation. On being much disturbed,
this fish appears to have fit, then
floats, belly upwards, at the same time
changing color. 1t Is suggested that
this seeming death struggle Is in
tended to keep off predatory fishes,
which prefer to take their prey in
health.
Fish scales have been cleansed and
dyed, and considerably used for decor
ative purposes. In France a novel de-
mand has now sprung up for the white
mucus with which these scales are
fabricated. This mucus is supplied by
| the bleak and other species, and it takes
10000 fishes to furnish a single pound.
Glass bulbs lined with this material
afford beautiful imitation pearls.
The Oldest mining company in the
world is represented in the Swedish de-
partment Of the Paris exposition. This
company began to produce copper in
production for nearly three centuries.
Reviewing the progress made in air
navigation Mr.. Henry Wilde finds that
the problem of flight remains about
where Leonardo da Vinci left 1t in 1900,
after inventing the arial screw and par
achute. Recent experiments have
strangely neglected the essential re-
quirements, which are that a flying
machine should have the power under
ordinary conditions to ascend or de-
scend at any place and any time; that
1t should be able to move in any direc-
ton or remain stationary above the
EARTH and that 1t should contain some
automatic principle Of safety to en-
able the aeronauts to reach the earth
without danger in the event of accident
to the mechanism. All means of navi-
eating the air thus far devised are lack
ing in one or more of these essentials.
Unless some new property of matter
should be discovered, the only promis-
ing means Of solving the problem seems
to be by applying power to the para
chute, for when the power Of ascending
is once given this, travelling in a hori-
zontal direction may be brought about
by inclining the parachute in the di-
rection Of motion required, while safe
descent is assured by the sustaining
surface. Soaring aeroplanes fail con-
spicuously, partaking more Of the
character of projectiles than Of the
means of locomotion.
The new gold-from- sea water scheme
pf prif fnuantnr
construction of shallow reservoir on
at high tide, allowing the water to en-
ter with such force as to scour the bot
| tom Of the reservoir and stir up the
sludge, and the discharge would be
gradual through an out let just above
| low water mark. 1t Is claimed that the
gold would adhere to the sludge, set
Ting with 1t in the reservoir. AS each
ton of sea water is assumed to con-
| tain from two to five grains Of gold, II
is easy to figure for such a reservoir
a valuable accumulation of precious
metal, which would be obtained periodi-
cally by fusion or dissolving the chalk
In acid.
A clock regulated by Hertzian waves
was novelty shown at the late Roya
society conversazione. 1t was sug
gested that all the clocks Of London
public and private could be controlled
by wireless telegraphy. coherer OF
each clock receiving the electric waves
and causing the time to be set to tina
4 the central transmitting clock.
A model of the human heart, working
as in life and pumping blood to and fr'
through artificial arteries, Is the worl
of French physician.
Bricks OF quartziferous sand mixe'
with small proportion of lime can b
made in many places where clay Is no
available, and they have the advan
tages Of being proof against water