Amador ledger., 1908-09-04

Lack of respiration by inland lakes
explains to Prof. II. A. Birge many
of the failures in stocking with trout
and other fish. The lake absorbs air
fer animal and plant life and exhales
nitrogen, oarbonic acid and some
times other gases; but it takes It's
only full inspiration in autumn, with
less complete one in spring, does
ing summer has but very shallow re-
spiration. When cooled to uniform
temperature near freezing, the wind
turns it over and over, saturating it
with one per cent by volumne of
oXygen-twice what the water can
hold at summer heat. This store
may suffice, life being most inactive
in winter, but there is sometimes a
shortage of oxygen ere the Ice is
gone. Another turning is given by
winds in spring. 1t is imperfect,
however, for the fast warming sur
face soon stops circulation of water
below, and the oxygen supply is
iessened during the warm period of
activity and greatest need. Tnus it
is that the bottom except in some
very deep lakes, where the stock Of
dissolved oxygen is large accumu-
lates carbonic acid and products of
decay to such an extent as to limit
the fish life that can be supported.
| As the earth crosses the orbits of
certain comets, shooting stars appear,
indicating that streams of fragments
are following in the wake of the
comets. Mr. W. +. Denning, the
British astronomer has lately suggest
ed that meteors radiating from the
constellation Aquarius during the
first week in May are in the orbit
of the famous Halley's comet, the
awaited, and as these meteors are
visible nearly every year the comet
dust must form an immense 'elliptical
ring reaching from near the sun to
point beyond Neptune's orbit. The
stream being densest just behind the
comet, great shower may come near
the periheliou passage probably In
May, 1910.
The great size of Jupiter, its mass
being greater than all other planets
combined and 2l3 times that OF the
earth, gives it great possible influence
upon such wanderers from space as
comets. 1t is supposed that most of
the comets of short period have been
visitors from outer space that ap-
preached near this great planet and
were so powerfully attracted that
they were unable again to pass be-
yond the attraction OF the sun but
were slowed down and confined to the
solar system in comparatively small
elliptic orbits. Prof. George Forbes
now attributes an even more remaIk
able capture to Jupiter by seeking to
identity the newly discovered eighth
satellite with the LeXelles comet of
1770. Good reasons for the theory
are shown but Prof. Iarrida del
Ma,moI, himself believing that the
satellite has been recently acquired
by Jupiter, finds evidence OF differ
ent source. lie thinks it was once an
asteroid. A late discovery is that the
asteroid ring between Mars and
Jupiter spreads out beyond the orbit
of the latter, and it is easy to sup
pose that one OF the little bodies has
come so near as to, be permanently
entIapped. This astronomer regards
the sixth and seventh satellites also
as former asteroids with Others yet
undiscovered.
Experiments have shown that the
human body. between the feet and
the hands, has an average electrical
resistance OF about 3. 600 ohms when
the hands and the oe-soles are wet,
and from 10000 to 10000 ohms when
hands aud feet are practically dry.
With the last resistance, l-20O
ampere current will pass through the
body if the hand completes 100 volt
circuit through the earth. In the
commonly used Alternating circuit of
100 volts and 50 cycles per second
there may be diHeulty in letting go
of the wire, and such a circuit of
500 volts is very danger Gus, especial
Iy ii traversing vital organs.
The photograph is suggested by a
French photograph as means of
timing when clock cannot be
watched lie has fitted his machine