Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1880-01-10
SCIENCE FAIRY LAND.
How to Amuse and Instruct both Old and
Young by few Simple scien-
tifc Experiments
NUMBER THREE. ]

into flask full Of water powdered sugar
may be sifted gently to considerable guam
tity. Why? Because the cotton wool is
matter which, if compressed, may be placed
in a very small bulk, which would not in
compressed form cause the spirits to over
flow from the flask. 1t is therefore not
contradiction of the rule that two things
cannot occupy the same space at once. As
to the sugar, that is difficult to explain
and understand. The ultimate, or smallest
particles or atoms of bodies only, are i'm
penetrable, and we may believe they are
not in close contact with each other. To
explain, fill turfbler with marbles, and
you will see spaces between them-for they
are round-and only the extremes of the
curves touch. Now, you can pour in and
shake down quantity of rape seed, and
still the tumbler is not full. Now, the
seeds being round, still leave spaces be-
tween them, and so you can put in fine
sand and shake it between the seeds, as
the sand-grains are round If you
could get anything finer, you could with
ease work it between the sand grains. If
you suppose the marbles to be the water,
and the rape seed to be the sugar, you will
see how it is the glass holds the sugar
though already full of water. The particles
of one body may thus enter into the spaces
left between those of another, without in
creasing its volume.
TWENTY FIRST EXPERIMENTATION say
vessel is empty when you pour out of it all
the water or apparent substance it contains.
Fill two glasses with water. Place each in
an empty pan. Lay an orange on the sur
face of the water of one of them. Take
cylindrical glass, open at one end, Ia fruit
or candy jar will do well). Make a small
hole through the closed end Place your
finger over the hole and endeavor, by in
verting the glass over the orange and
pressing upon the surface of the water, to
make it enter the glass cylinder. The re-
sistance of the air will cause the water to
overflow into the pan and the orange will
not enter, but try it on the other vessel,
leaving the hole open, and you will find the
orange will enter the glass and the air will
rush out of the hole. This makes clear to
the young mind how it is that air and all
gases fill space the same as other things do,
and only are displaced by being crowded
out of the way.
TWENTY SECOND EXPERIhENT-Cen
fugal force may be illustrated by spinning
parasol in the hand As it revolves it
will open, illustrating that power which
drives revolving body from the center,
and is called centrifugal force. Boys will
find fine illustration oil centrifugal force
by suspending broad tin can, broader at
top than bottom, by three strings, which,
being filled with water and the strings
twisted and then released, revolves rapidly
The water will be seen to fly from the
edges of the can in circle of spray The
rolling of a hoop, the spinning of top,
etc., illustrate the fact that the force of
gravitation (by which every particle at
tracts every other particle) is overcome by
centrifugal force which imparts to the re-
volving body motion in the direction of a
tangent tango, to touch) to circle.
TwENTY-THIRD EXPERIMENT. - Illus
trate the manner of the occurrence of sim.
pie echpses by passing small spherical
body between the rays of toy magic
lantern and large spherical body as an
apple and a nut, suspended by strings
Suppose your spectator to be on the apple
at the point where the shadow falls. look
ing toward the lantern, representing the
sun, and his sight being intercepted by the
moon passing between him and the sun, he
may be presumed to understand why the
moon appears black. By moving the
small globe here and there it can be shown
why eclipses are only visible at certain
points on the earth, because it would take
fifty globes as large as the moon to make
one equal in size to the earth, and hence
the shadow of the moon is necessarily small
and cannot obscure the whole hemisphere
of the earth turned toward it. This illus
trates an eclipse of the sun, and gives the
appearance of black body or screen pass
ing over the face of the sun. An eclipse
of the moon may be illustrated by causing
the earth sphere to pass between the light
and the moon sphere, when the shadow of
the earth will darken the moon. 1t will
be easy to show to the child by this means
why an eclipse of the moon can be seen
from more points on the earth than is pos
sible in an eclipse of the sun. The differ
ence between an annular and total eclipse
will be hereafter explained.
TWENTY FOURTH EXPERIMENT. = The
attraction of cohesion is an invisible force
Cast lead into two pieces like weights and
scrape the ends nicely and evenly, taking
care not to touch the surfaces with the
fingers. Press the scraped surfaces to-
gether with slight grinding motion, and
the two pieces will cohere or cling together
so that one may be lifted by lifting the
other, and will, if suspended, for some time
retain their positions. This is not caused
by pressure of the air, for they will CO.
here in a vacuum, i. e., in space from
which the air has all been drawn by an
air pump. Break the attachment forcibly
and examine one of the surfaces and you
will see but limited number of points,
like pin points, where the cohesion &C.
Cured. Glass, when melted, is soft and
liquid mass, but when cooled becomes hard
and firm, the particles clinging together by
the attractive force of cohesion. If you
cannot cast the leaden weights above
mentioned take bit of bar lead, to be had
at any grocery store, nearly, and cut off
two pieces clearly and use them
for the experiment. Next take four
inches of the bar, dexterously
shave off thick shaving, and press
part of its face upon the planed surface of
the large piece, and you will be able $50
powerful is the cohesion) to lift the larger
by the smaller piece. Cut an apple
through with sharp knife and then press
the surfaces together, and the two pieces
will cohere. So, too, with an incised or
cut wound, if the edges of the
flesh are put together and so held
few moments, cohesion occurs.
Should you cut off the top of your finger
you can place back the severed part, and
by cohesion it will adhere and grow fast
very soon. The art of plating copper with
silver which is afterwards gilt, and then
drawn out into fiattened wire for the manu-
facture of gold lace, usually called bullion,
is wonderful example of the power of
cohesion, the cohesion of the particles of
gold, of which single grain may be ex-
tended over the finest plate-wire 345 feet
in length. Thus the tenacity of metals is
but the power of cohesion of the metallic
PARTICLES.
TWENTY FIFTH ExPERIMENT.-Take a
piece of tin, some II inches long and 6
inches broad. Lay its ends on two blocks.
Thus suspended a few ounces of weight
bends it down to the ground. But roll it
up in a tight roll and you may suspend
very many pounds from it without its
yelling particle. This illustrates the
strength of cellular construction. On this
plan the Great Eastern steamship was
built, She having, up to the water-mark,
an inner and outer metal shell of three
quarter-inch plate, placed three feet ten
inches apart, and between them, at inter
walls of six feet, run horizontal webs of
iron plates, which convert the whole into
a series of continuous cells or iron boxes