The National tribune., 1898-03-31

coal oil may be mixed with it. In either
case, it is well to treat it with acid as
described for turpentine, since the presence
OF even trace OF water hinders solution of
rubber. The benzine solution so obtained
is thin liquid containing about one per
cent. OF caoutchouc. 1t must be kept in
the dark. Chloroform, carbon, bisulphide,
ether and benZol can also be used as sol
vents. But none Of these are thoroughly
satisfactory.
81. The so-called pebble glasses" fspec-
tacleS) are made of transparent colOrlcSS
rock crystal or quartz, usually from Brazil,
which is harder than glass and so less
liable To be scTatched.-Asa W. Slayton.
So. hen the metal aluminium burns in
air, it forms white oxide called alumina.
This alumina is found native in crystal
line form as variously-colored, intensely
hard crystals. Those crystals which are
transparent enough are used as gems; the
blue ones being called sapphres, the red
ones rubeS the yellow ones Oriental
tOpazes, the violet ones Oriental anne
thystS. When Opaque, and not suited for
ieWelry, cryStalliZed alumina is called cor
undum, and largely used as an abrasive.
When corundum is found in an impure,
granular state it is called emery. But all
these various substances are one and the
same chemically, that Il cheap emery
wheel may represent what would be an
enormous fortune had the alumina con-
in large and clear transparent red crystals
instead OF little Opaque black ones.
81. In answer To the question, How many
arc lights it would take 10 light a town a s
well as the moon does if removed to an equal
distance, should say 300 billion. The
conditions stated are: An electric light tower
14S.5 feet high carries 4 arc lights, casts
at 800 rods distance shadow Of equal
density to that cast by the full moon.
Tower 1877 feet high equals rods; Souar-
ing this and distance from tower 30H
rods, add, and extract root. we have al
most 32-call it 32-rods TO the lights and
2i0 600 miles TO the moon. Now, the in
tensty of light is inversely as the square
of the distance; that is, 3 times farther
away, nine times less light; four times
farther, 16 times less, etc. Thirty two
rods is one-tenth of mile; square 10 and
we have the equivalent Of 100 towers at
one mile; square moons distance and
multiply by 100 gives $50 billion towers.
q, 0i0 billion lights; enough placed one
foot apart TO reach around the earth;
enough for 6,325,S ST. on each square mile
of the face of the moon, or to cover the
whole face toward the earth if two feet
apart each way. And that would only be
'moonshine," one 300-thousandth-som
say 618-thousandth-Of sunshine. Fetch
out your dynamOs,-Asa W. Slayton.
S.. A weber is the amount OF electricity
flowing in one second through a circuit
"ncTc the force Is one volt ana the re-
sistance is one ohm.-Asa w Slayton.
So. If the revolution Of the earth on its
axis should stop, everything movable
would 90 tumbling eastward with velocitieS
varying from 600 miles an hour down, ac-
cordng to distance from the Equator. Trees
would be uprooted, all buildings thrown
down mountainous torn asundcr and the
continents flooded by the oceans. There
after we should have but one day and one
night in a year, each six months long all
over the earth; and the sun would rise in
the west and set in the east and so would
the moon. The stars would never rise and
set, each six months night showing the
same stars cons family in the same places
We would have new, half and full moon
six and half times each night. The
ocean waters would flow to the poles, MAX
ing the polar oceans about seven miles
deeper, flooding the adjacent continents,
and lowering the equatorial oceans about
five miles, probably, leaving continuous
continent clear around the earth with all
its lands and mountains about five miles
higher above Sea-leyel than they now are
Equatorial currents would cease, and there
would be but two flood tides in each
month, and they would flow east instead
of west. II the stop happened while il wa S
Summer and day in North America, then
We should always have Summer during
our six months day and Winter in our six
months night; and Asia would have six
months Summer all her night, and all
Winter during her day. Patagonia would
have Winter her six months day, and
Summer during her night Australia ha We
Summer her day, and Winter her night.
The Mississippi, Hudson and Voga would
flow north ms tead of south and with fearful
| VelOcitieS.-Asa w. SlaytOn